ENULIUS FLAVITORQUES
PACIFIC LONGTAIL SNAKE

(COPE, 1869)

ADULT LENGTH
53/4–193/4 in (400–500 mm)

The Pacific Longtail Snake occurs from Jalisco, on the southwestern coast of Mexico, through Central America to Colombia, being found up to elevations of 5,910 ft (1,800 m) asl, inhabiting both wet and dry forest. It also inhabits savannas or thornscrub and is active both diurnally and nocturnally, although it is a secretive, semi-fossorial species that inhabits rotten logs and hides under rocks or in crevices in the soil. It feeds on termites, ants, and their larvae, and also reptile eggs. The scientific name suggests this species has a yellow color but unicolor specimens lacking such a marking are common. The tails of longtail snakes are thick but fragile and they are often truncated. This is an oviparous snake that lays up to two eggs.

RELATED SPECIES

Three other species of Enulius are recognized: the Endangered Roatán Longtail Snake (E. ruatanensis) and Guanaja Longtail Snake (E. bifoveatus), both from the Islas de la Bahia, and the Mexico Longtail Snake (E. oligostichus) from southern Mexico. The related Colombian Longtail Snake (Enuliophis sclateri) was once also included in the genus Enulius. Three subspecies are recognized, two in Mexico (E. f. sumichrasti and E. f. unicolor), while the nominate subspecies occurs in Central America.

FAMILY	Dipsadidae: Dipsadinae
RISK FACTOR	Rear-fanged, mildly venomous, harmless to human
DISTRIBUTION	Central America: southwestern Mexico to Colombia
ELEVATION	0–5,910 ft (0–1,800 m) asl
HABITAT	Lowland and midmontane wet and dry tropical or deciduous forest, savanna, thornscrub
DIET	Termites, ants, and reptile eggs
REPRODUCTION	Oviparous, with clutches of 1–2 eggs
CONSERVATION STATUS	IUCN Least Concern

The Pacific Longtail Snake is a small, extremely slender snake with smooth glossy scales, a rounded head slightly broader than the neck, and a long tail. It is gray in color, darker above than below, sometimes with a broad off-white or yellow collar, but frequently lacking this marking.

GEOPHIS BRACHYCEPHALUS
SHORT-HEADED EARTHSNAKE

COPE, 1871

ADULT LENGTH
113/4–18 in (300–460 mm)

The Short-headed Earthsnake is found in central Costa Rica and western Panama, with a small disjunct population in eastern Panama, just east of the Canal, possibly attributed to this species. It is an inhabitant of low montane and lowland rainforest, although it is much more common at higher elevations than in the lowlands. It is also found in disturbed areas and low montane pastures. It may be found under rocks, logs, fallen branches, and other forest-floor debris. As with all other Geophis earthsnakes for which dietary preferences are known, this species feeds exclusively on earthworms. Although a rear-fanged, mildly venomous species, it is completely harmless to humans, does not bite, and could do no damage if it did. Females are egg-layers.

RELATED SPECIES

The genus Geophis takes over from the South American genus Atractus (shown here) in Central America, with few of the 50 known species entering eastern Panama or the Chaco of Colombia. Colombian specimens of G. brachycephalus are regarded as representing a different species, the Colombian Earthsnake (G. nigroalbus).

FAMILY	Dipsadidae: Dipsadinae
RISK FACTOR	Rear-fanged, mildly venomous; harmless to humans
DISTRIBUTION	Central America: Costa Rica and Panama
ELEVATION	50–6,940 ft (15–2,115 m) asl
HABITAT	Low montane and lowland rainforest, and rough grassland or cleared areas
DIET	Earthworms
REPRODUCTION	Oviparous, with clutches of 3–6 eggs
CONSERVATION STATUS	IUCN Least Concern

The Short-headed Earthsnake is a small, keel-scaled snake with a blunt head, small eyes, and a short tail. Its coloration and patterning consist of a brown, gray, or black dorsum, with a fine white nuchal collar in juveniles, and either a pair of red-orange dorsolateral longitudinal stripes or orange-red blotches on the flanks that may form crossbars. The venter is immaculate white. This species has a shorter, more rounded head than some of its congeners.

GEOPHIS LATIFRONTALIS
SAN LUIS POTOSÍ EARTHSNAKE

GARMAN, 1883

ADULT LENGTH
113/4–161/2 in (300–420 mm)

The San Luis Potosí Earthsnake is one of the northernmost members of the North and Central American earthsnake genus Geophis. It is found only in the Mexican states of San Luis Potosí, Hidalgo, and Querétaro. It inhabits low montane rainforest where it exists as a semi-fossorial burrower living under rotten logs, rocks, and forest-floor debris. It may also be found under trash discarded by humans. In common with its congeners it is an oviparous species with clutches of up to four eggs. It feeds on earthworms, and possibly other soft-bodied invertebrates. The San Luis Potosí Earthsnake defends itself by smearing noxious-smelling cloacal secretions on its perceived enemy. A mildly venomous rear-fanged species, it is of no threat to humans.

RELATED SPECIES

Two subspecies of Geophis latifrontalis are recognized, the unicolor nominate San Luis Potosí Earthsnake (G. l. latifrontalis) and the Red-banded Mountain Earthsnake (G. l. semiannulatus). A further 30 species of Geophis earthsnakes occur in Mexico but none enter the United States.

FAMILY	Dipsadidae: Dipsadinae
RISK FACTOR	Rear-fanged, mildly venomous; harmless to humans
DISTRIBUTION	North America: Mexico
ELEVATION	2,620–8,530 ft (800–2,600 m) asl
HABITAT	Low montane rainforest
DIET	Earthworms, possibly soft-bodied invertebrates
REPRODUCTION	Oviparous, with clutches of up to 4 eggs
CONSERVATION STATUS	IUCN Data Deficient

The San Luis Potosí Earthsnake is a small, smooth-scaled snake with a rounded head, small eyes, and a short tail. It may be uniform brown or gray above, with some specimens exhibiting body patterning comprising a series of orange or red-orange rings or broken bands. The venter is off-white but may be flecked with grayish brown.

HYDROMORPHUS CONCOLOR
CENTRAL AMERICAN WATERSNAKE

PETERS, 1859

ADULT LENGTH
283/4–331/2 in (730–850 mm)

The widely distributed, but infrequently encountered, Central American Watersnake is found from northeastern Guatemala to Panama. It is an aquatic or semi-aquatic inhabitant of lowland and low montane rainforest where it occurs along streams, and in or near ponds. It shelters under piles of decaying vegetation or on the muddy bottom and, being aquatic, it has relatively dorsally positioned nostrils to enable it to breathe at the surface. It is most active at night and it may even be found crossing roads after heavy rain. It is believed to feed on freshwater shrimps, fish, or frogs but there are few definitive reports regarding the diet of this species. Females are oviparous, laying clutches of four to seven eggs. The Central American Watersnake is harmless to humans.

RELATED SPECIES

A second species of Hydromorphus is recognized, the Panamanian Watersnake (H. dunni), which is known only from a single low montane locality in western Panama. The genus Hydromorphus is most closely related to the Central American swamp snake genus Tretanorhinus (shown here).

FAMILY	Dipsadidae: Dipsadinae
RISK FACTOR	Nonvenomous
DISTRIBUTION	Central America: Guatemala, Honduras, Nicaragua, Costa Rica, and Panama
ELEVATION	0–4,920 ft (0–1,500 m) asl
HABITAT	Streams and ponds in lowland and low montane rainforest
DIET	Possibly freshwater shrimps, fish, or frogs
REPRODUCTION	Oviparous, with clutches of 4–7 eggs
CONSERVATION STATUS	IUCN Least Concern

The Central American Watersnake is a shiny, smooth-scaled snake with a cylindrical body, a narrow head that is barely distinct from the neck, small eyes, and a short tail. It is uniform light or dark brown above, although the dorsum may also bear scattered dark brown spots, while the venter is yellowish or pale brown.

HYPSIGLENA CHLOROPHAEA
DESERT NIGHTSNAKE

COPE, 1860

ADULT LENGTH
8–113/4 in, rarely 233/4 in (200–300 mm, rarely 600 mm)

The most northerly member of the genus Hypsiglena, the Desert Nightsnake is found from southern British Columbia in Canada, throughout western USA, to the northwest Mexican states of Chihuahua and Sonora. As its common name suggests it is a nocturnally active denizen of desert and semidesert. It shelters during the day, either burrowed into the sand or in the burrows of small mammals, reptiles, or spiders, emerging at night to hunt its primary prey of small lizards. Desert Nightsnakes also occasionally take small snakes, mice, toads, and large invertebrates. Although its toxic oral secretions will rapidly paralyze small prey, the small size of this snake, its reluctance to bite, and its lack of large rear fangs mean it is considered harmless to humans. Desert Nightsnakes may be found on desert roads at night.

RELATED SPECIES

Hypsiglena chlorophaea was formerly treated as a subspecies of the Collared Nightsnake (H. torquata), which is now confined to Mexico. As a separate species it contains four subspecies: the nominate Sonoran Nightsnake (H. c. chlorophaea), the Northern Desert Nightsnake (H. c. deserticola), the Mesa Verde Nightsnake (H. c. loreala), and the Tiburon Island Nightsnake (H. c. tiburonensis). A former subspecies, the Santa Catalina Island Nightsnake (H. catalinae) has been elevated to specific status. Hypsiglena contains a further six species in western USA and Mexico.

FAMILY	Dipsadidae: Dipsadinae
RISK FACTOR	Mildly venomous; harmless to humans
DISTRIBUTION	North America: Canada, USA, and Mexico
ELEVATION	0–5,070 ft (0–1,545 m) asl
HABITAT	Desert and semidesert
DIET	Lizards; also toads, snakes, invertebrates, and small mammals
REPRODUCTION	Oviparous, with clutches of 2–9 eggs
CONSERVATION STATUS	IUCN not listed

The Desert Nightsnake is a small snake with smooth scales, an angular, pointed head that is distinct from the neck, and eyes with vertically elliptical pupils. Coloration is predominantly pastel shades, like its habitat, with pale grays or browns, rows of darker blotches of the same color, and large blotches over the neck forming a broken collar.

IMANTODES CENCHOA
COMMON BLUNT-HEADED TREESNAKE

LINNAEUS, 1758

ADULT LENGTH
3 ft 3 in–4 ft 3 in (1.0–1.3 m)

Although the Common Blunt-headed Treesnake is a very common and widely distributed species, it often evades discovery due to its nocturnal and highly arboreal habits, its cryptic coloration, and liana-like body shape, combined with its ability to remain stationary for long periods. This species is primarily an inhabitant of pristine wet or dry forest, especially near water, but it is also found in plantations and secondary growth. It is believed to sleep during the day, inside bromeliads or under bark, but even then it is difficult to find. Sometimes specimens are seen on the ground, crossing trails. It preys on frogs and lizards, particularly anoles, which are captured while they sleep, and it uses its weak venom and constriction to subdue its prey.

RELATED SPECIES

The genus Imantodes contains seven other species. Three widely distributed species, with which I. cenchoa occurs in sympatry, are the Central American Blunt-headed Treesnake (I. gemmistratus), the Western Blunt-headed Treesnake (I. inornatus), and the Amazon Blunt-headed Treesnake (I. lentiferus). Other species are more localized, in the Yucatán, Mexico (I. tenuissimus), Darién Gap, Panama (I. phantasma), Chocó, Colombia (I. chocoensis), and Santander, Colombia (I. guane). These snakes also resemble the slug- and snail-eating snakes (Dipsas and Sibon).

FAMILY	Dipsadidae: Dipsadinae
RISK FACTOR	Rear-fanged, mildly venomous; harmless to humans
DISTRIBUTION	North, Central, and South America: southern Mexico to northern Argentina
ELEVATION	0–6,560 ft (0–2,000 m) asl
HABITAT	Low montane and lowland rainforest and dry forest, plantations, and secondary growth
DIET	Lizards and frogs
REPRODUCTION	Oviparous, with clutches of 1–3, rarely 8, eggs
CONSERVATION STATUS	IUCN not listed

The Common Blunt-headed Treesnake is an extremely slender and elongate, laterally compressed snake with smooth scales, a long tail, and a bulbous head with large protruding eyes and vertically elliptical pupils. It is orange to tan dorsally with a series of bold, black-edged, dark orange to red vertebral saddles, and a yellow iris to the eye.

LEPTODEIRA ANNULATA
BANDED CAT-EYED SNAKE

(LINNAEUS, 1758)

ADULT LENGTH
153/4–271/2 in, rarely 311/2 in (400–700 mm, rarely 800 mm)

The Banded or Common Cat-eyed Snake is so-called because it has the vertically elliptical pupils of a nocturnal predator. It inhabits secondary growth, disturbed habitats, savanna–forest edge situations, and the vegetation around or along watercourses, where it hunts tree frogs and their eggs, with lizards also featuring in its diet. It is also frequently encountered around buildings and as a semi-arboreal species it may be found moving over the ground at night. Although a rear-fanged venomous species, the commonly encountered Banded Cat-eyed Snake is generally inoffensive and its venom is too weak to harm humans. It is widely distributed through the northern half of South America, east of the Andes, and it also occurs on several offshore islands, including Trinidad, Tobago, and Isla Margarita, off Venezuela.

RELATED SPECIES

Three subspecies are recognized, the nominate form (Leptodeira annulata annulata) in the Amazon Basin, a northern form (L. a. ashmeadi), and southern form (L. a. pulchriceps). The genus Leptodeira also contains a further 11 species. The Northern Cat-eyed Snake (L. septentrionalis) occurs as far north as Texas, while Baker’s Cat-eyed Snake (L. bakeri) is found in Venezuela and on Aruba Island. Leptodeira is related to the treesnakes of genus Imantodes (shown here).

FAMILY	Dipsadidae: Dipsadinae
RISK FACTOR	Rear-fanged, mildly venomous; harmless to humans
DISTRIBUTION	South America: Panama to northern Argentina, also Trinidad, Tobago, and Isla Margarita
ELEVATION	0–7,550 ft (0–2,300 m) asl
HABITAT	Lowland and upland secondary forest, gallery forest, and edge situations
DIET	Frogs and their eggs, and lizards
REPRODUCTION	Oviparous, with clutches of 3–6 eggs
CONSERVATION STATUS	IUCN not listed

The Banded Cat-eyed Snake is a relatively slender, laterally compressed snake with smooth scales, a long tail, and a broad head with large, protruding eyes and vertically elliptical pupils. It is brown to orange with a dorsal pattern of black or dark brown diamonds or blotches that may coalesce to form an irregular zigzag pattern.

NINIA SEBAE
RED COFFEE SNAKE

(DUMÉRIL, BIBRON & DUMÉRIL, 1854)

ADULT LENGTH
6–151/4 in (150–386 mm)

The tiny, forest floor-dwelling Red Coffee Snake is a mimic of several Central American coralsnake species (Micrurus), but is itself harmless. It is found in a wide variety of closed canopy and open habitats from Mexico to Panama, hiding under logs or in leaf litter during the day. At night it is active, hunting earthworms, slugs, and snails, as part of a guild of snakes referred to by ecologists as “goo-eaters.” Snakes in this guild possess special oral secretions to enable them to feed on slimy prey without becoming “glued-up” with their defensive secretions. Snakes of the genus Ninia are referred to as “coffee snakes” because they are often found in coffee plantations. The Red Coffee Snake is named for Albertus Seba (1665–1736), a Dutch collector and author of Cabinet of Natural Curiosities.

RELATED SPECIES

Four subspecies are recognized, from the Yucatán, Mexico (Ninia s. morleyi), Guatemala (N. s. punctulata), and southeast Nicaragua to Panama (N. s. immaculata), with the nominate form occupying the remainder of the range. Ten other species of coffee snake occur from Mexico to Trinidad. Espinal’s Coffee Snake (N. espinali), from Honduras and El Salvador, is considered to be Near Threatened by the IUCN, while a recently described species(N. franciscoi) is known only from its Trinidadian holotype.

FAMILY	Dipsadidae: Dipsadinae
RISK FACTOR	Rear-fanged, mildly venomous; harmless to humans
DISTRIBUTION	North and Central America: southern Mexico, Belize, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, and Panama
ELEVATION	0–6,560 ft (0–2,000 m) asl
HABITAT	Lowland and low montane rainforest, dry forest, savanna, pasture, and coffee plantations
DIET	Earthworms, slugs, and snails
REPRODUCTION	Oviparous, with clutches of 1–4 eggs
CONSERVATION STATUS	IUCN Least Concern

The Red Coffee Snake is a diminutive snake with smooth scales, a head distinct from the neck, small eyes with vertically elliptical pupils, and a moderately long tail. It is red to pink above with a black cap over the dorsum of the head, and a yellow and black collar. It is immaculate white below.

NOTHOPSIS RUGOSUS
ROUGH COFFEE SNAKE

COPE, 1871

ADULT LENGTH
8–15 in, rarely 17 in (200–380 mm, rarely 430 mm)

The Rough Coffee Snake is unlike any other snake within its range. It has been linked with the xenodermatid snakes of Southeast Asia, such as the Dragon Snake (Xenodermus javanicus), due to its unusual appearance. Unique features of the Rough Coffee Snake include the fragmentation of most of its dorsal head scutes into numerous granular scales, and the keeling of the head and body scales, a morphology usually associated with boas or pitvipers. Distributed from Honduras to Ecuador, it is a rare snake known from only a few specimens. It is a secretive inhabitant of tropical rainforest floors, hiding under logs or in leaf litter. Prey includes salamanders and small frogs, and possibly also small lizards. It has enlarged rear teeth and possibly Duvernoy’s glands, but is harmless to humans.

RELATED SPECIES

Despite appearances, the monotypic Nothopsis rugosus is related to other Central American snakes such as the blunt-headed treesnakes (Imantodes) and the cat-eyed snakes (Leptodeira).

FAMILY	Dipsadidae: Dipsadinae
RISK FACTOR	Rear-fanged, mildly venomous; harmless to humans
DISTRIBUTION	Central and South America: Honduras, Nicaragua, Costa Rica, Panama, Colombia, and Ecuador
ELEVATION	0–3,280 ft (0–1,000 m) asl
HABITAT	Lowland to low montane rainforest
DIET	Frogs, salamanders, possibly lizards
REPRODUCTION	Oviparous, with clutches of up to 3 eggs
CONSERVATION STATUS	IUCN Least Concern

The Rough Coffee Snake is a slender snake that is characterized by its strongly keeled body scales, and rugose, granular head scales. It has a relatively long tail, a head distinct from the neck, and small eyes with vertical pupils. It may be dark brown or light yellowish brown with darker brown reticulations, wavy stripes, and blotches.

PLIOCERCUS ELAPOIDES
VARIEGATED FALSE CORALSNAKE

COPE, 1860

ADULT LENGTH
113/4–193/4 in, rarely 303/4 in (300–500 mm, rarely 780 mm)

As its common name suggests, this is an extremely variably patterned snake. It occurs across a wide area of Mexico and northern Central America and may be difficult to identify to species. The Variegated False Coralsnake is an excellent mimic of several highly venomous coralsnakes (Micrurus), its pattern seemingly varying to match that of the local coralsnakes across its range. Although not lethal, bites should be avoided as they have caused localized pain and swelling, and even severe pain and tissue discoloration that may take weeks to recover. A wet or dry forest species, this snake is also found in coffee plantations and other cultivated areas, where it is active by day or night on the forest floor. It feeds on frogs, salamanders, and amphibian eggs.

RELATED SPECIES

Five subspecies are recognized, from Puebla to Chiapas (Pliocercus elapoides elapoides), Veracruz to Yucatán and Honduras (P. e. aequalis), Oaxaca to Guatemala (P. e. diastema), Pacific coastal Oaxaca (P. e. occidentalis), and Caribbean coastal Veracruz (P. e. wilmarai). The genus Pliocercus also contains three other species: Andrew’s False Coralsnake (P. andrewsi) on the northern Yucatán Peninsula, the Northern False Coralsnake (P. bicolor) from Tamaulipas to Veracuz, and the Southern False Coralsnake (P. euryzonus) from Guatemala to Peru. Pliocercus is closely related to the thick-tailed snakes of genus Urotheca (shown here).

FAMILY	Dipsadidae: Dipsadinae
RISK FACTOR	Rear-fanged, venomous
DISTRIBUTION	North and Central America: southern Mexico, Guatemala, Belize, Honduras, and El Salvador
ELEVATION	0–6,500 ft (0–1,980 m) asl
HABITAT	Lowland and low montane rainforest and dry forest, also coffee plantations and cultivated areas
DIET	Frogs, salamanders, and amphibian eggs
REPRODUCTION	Oviparous, with clutches of 4–8 eggs
CONSERVATION STATUS	IUCN Least Concern

The Variegated False Coralsnake is a moderately slender snake with a rounded head, distinct from the neck, and round pupils to the eyes. It has smooth scales and the tail is often truncated. Many populations exhibit a banded coralsnake-mimic pattern of red-yellow-black-yellow-red, but some specimens (P. e. wilmarai) lack the black bands.

PSEUDOLEPTODEIRA LATIFASCIATA
FALSE CAT-EYED SNAKE

(GÜNTHER, 1894)

ADULT LENGTH
153/4–193/4 in, rarely 271/2 in (400–500 mm, rarely 700 mm)

The boldly patterned False Cat-eyed Snake occurs in the southwest Mexican states of Colima, Oaxaca, Guerrero, Michoacán, Morelos, Puebla, and Jalisco, where it inhabits tropical semi-deciduous forest and coastal lowland forest. Terrestrial and nocturnal, it is not a commonly encountered species. Although it resembles the cat-eyed snakes of genus Leptodeira, it is not closely related to them and it possesses ungrooved, rather than strongly grooved, rear fangs, among other defining characteristics. This species is known to enter buildings in search of geckos, but it also eats frogs. The False Cat-eyed Snake is a poorly known species that is believed to be oviparous, but its clutch size is unknown.

RELATED SPECIES

Although Pseudoleptodeira latifasciata does resemble members of the genus Leptodeira it is more closely related to the nightsnakes of genus Hypsiglena (shown here), and it was at one time included in that genus. Pseudoleptodeira is now a monotypic genus, Uribe’s Cat-eyed Snake (L. uribei) being transferred to Leptodeira.

FAMILY	Dipsadidae: Dipsadinae
RISK FACTOR	Rear-fanged, mildly venomous; harmless to humans
DISTRIBUTION	North America: southern Mexico
ELEVATION	330–5,910 ft (100–1,800 m) asl
HABITAT	Tropical semi-deciduous forest
DIET	Lizards and frogs
REPRODUCTION	Oviparous, clutch size unknown
CONSERVATION STATUS	IUCN Least Concern

The False Cat-eyed Snake is a laterally compressed snake with smooth scales, a relatively long tail, and a distinct head with moderate eyes and vertically elliptical pupils. The head is white with a heavy infusion of black on every scale and a red dorsum and neck, followed by a black nape band. The body is white with broad black or brown saddles that almost form complete rings, the white interspaces being unmarked and relatively narrow.

RHADINAEA DECORATA
CENTRAL AMERICAN GRACEFUL BROWNSNAKE

(GÜNTHER, 1858)

ADULT LENGTH
133/4–153/4 in, rarely 181/2 in (350–400 mm, rarely 470 mm)

Also known as the Adorned Graceful Brownsnake, this species is found from southeastern Mexico, through Central America, to Colombia and Ecuador in northwestern South America. It is a diurnal leaf-litter inhabitant of lowland and low montane rainforest, and also inhabits secondary growth areas and coffee plantations, though it is less common in disturbed habitats than pristine rainforest. It preys on terrestrial frogs and their eggs, and also salamanders, lizards, and earthworms. It appears to be most active on overcast days or following rain. As a small snake, the female Central American Graceful Brownsnake produces clutches comprising up to four eggs.

RELATED SPECIES

The 21 snakes of genus Rhadinaea are also known as forest snakes or littersnakes. Eleven species belong to the R. decorata group, but only R. decorata itself occurs outside of Mexico. Rhadinaea is related to the dwarf brownsnakes (Rhadinella) and the leaf-litter snakes (Taeniophallus).

FAMILY	Dipsadidae: Dipsadinae
RISK FACTOR	Rear-fanged, mildly venomous; harmless to humans
DISTRIBUTION	North, Central, and South America: southeastern Mexico, Belize, Guatemala, Honduras, Nicaragua, Costa Rica, Panama, Colombia, and Ecuador
ELEVATION	0–5,740 ft (0–1,750 m) asl
HABITAT	Lowland and low montane rainforest, secondary growth, and coffee plantations
DIET	Frogs, salamanders, amphibian eggs, lizards, and earthworms
REPRODUCTION	Oviparous, with clutches of 1–4 eggs
CONSERVATION STATUS	IUCN not listed

The Central American Graceful Brownsnake is a slender, smooth-scaled snake, with a long, often truncated tail, a narrow but distinct and pointed head, and moderately large eyes with round pupils. It is dark brown with a pair of pale brown longitudinal stripes, which begin on the neck as yellow stripes and broaden as they continue onto the body. A white stripe passes along the lips, while broken yellow or white lines exit the rear of the eye.

RHADINAEA FLAVILATA
PINEWOODS SNAKE

(COPE, 1871)

ADULT LENGTH
93/4–113/4 in, rarely 153/4 in (250–300 mm, rarely 400 mm)

The only member of the genus Rhadinaea in the United States, the Pinewoods Snake is found from the Carolinas to Florida and west to southern Louisiana and Mississippi. It inhabits pinewood flatlands and adjacent hardwood hammocks in Florida, and coastal marshes and islands in the Carolinas, and adopts a semi-fossorial existence, living under logs or bark or buried in the sandy soil. It is said to estivate in crayfish burrows during dry weather. Prey consists of small frogs, salamanders, and lizards, which are subdued by the snake’s weak venom. Like many small snakes it has many enemies, such as ophiophagous snakes, birds of prey, and carnivorous mammals, and it is also vulnerable to habitat destruction, fragmentation, or alteration. Pinewoods Snakes do not bite, but expel a noxious secretion from the cloacal glands.

RELATED SPECIES

Rhadinaea flavilata is the only member of its genus in the United States. A close relative may be the Crowned Graceful Brownsnake (R. laureata) from central Mexico.

FAMILY	Dipsadidae: Dipsadinae
RISK FACTOR	Rear-fanged, mildly venomous; harmless to humans
DISTRIBUTION	North America: southeastern USA
ELEVATION	0–625 ft (0–190 m) asl
HABITAT	Lowland pinewoods, hardwood hammocks, and coastal marshes
DIET	Frogs, salamanders, and lizards
REPRODUCTION	Oviparous, with clutches of 1–4 eggs
CONSERVATION STATUS	IUCN Least Concern

The Pinewoods Snake is a small, smooth-scaled snake with a short tail that ends in a terminal spine, a head slightly broader than the neck, and moderately large eyes with round pupils. It is red-brown in color, paler below, with yellow or white lips and a red iris.

RHADINELLA SERPERASTER
COSTA RICAN GRACEFUL BROWNSNAKE

(COPE, 1871)

ADULT LENGTH
14–171/2 in (360–445 mm)

The Costa Rican Graceful Brownsnake, also known as the Striped Littersnake, is confined to low to medium elevations in the Cordilleras de Tilarán and Talamanca in north and central Costa Rica. This small snake is terrestrial or semi-fossorial, being located under logs on the rainforest floor but sometimes found as deep as 20 in (50 cm) below the surface in soft, humid rainforest soil. It is believed to feed on reptile eggs, especially those of earthsnakes of the genus Geophis (shown here). Although it is technically venomous it is inoffensive and harmless to humans. It is oviparous, with clutches of up to six eggs being laid.

RELATED SPECIES

The genus Rhadinella contains 17 species, most of which previously constituted the Rhadinaea godmani group. Most species are extremely localized in their distribution, the only other species occurring in Costa Rica being the widely distributed Godman’s Graceful Brownsnake (R. godmani).

FAMILY	Dipsadidae: Dipsadinae
RISK FACTOR	Rear-fanged, mildly venomous; harmless to humans
DISTRIBUTION	Central America: Costa Rica
ELEVATION	3,810–7,220 ft (1,160–2,200 m) asl
HABITAT	Low montane wet forest and rainforest
DIET	Reptile eggs
REPRODUCTION	Oviparous, with clutches of up to 6 eggs
CONSERVATION STATUS	IUCN Least Concern

The Costa Rican Graceful Brownsnake is a diminutive snake with smooth scales, a relatively short tail, and a slightly pointed head with small eyes and round pupils. The dorsum of the head is dark brown, the lips are white, and the body is brown with a series of tan and dark brown longitudinal stripes.

SIBON LONGIFRENIS
LICHEN SNAIL-EATER

(STEJNEGER, 1909)

ADULT LENGTH
193/4–271/2 in (500–700 mm)

The Lichen Snail-eater occurs in Honduras, Nicaragua, Costa Rica, and Panama where it inhabits lowland wet forest and rainforest, especially near water. Nocturnal and arboreal, its cryptic camouflage means it is rarely encountered, and less well known than some of its congeners. It patterning resembles that of lichen-patterned Eyelash Palm-pitvipers (Bothriechis schlegelii), but whether this is coincidental or mimicry is not known. The Lichen Snail-eater feeds on slugs and snails, withdrawing the latter from their shells by hooking them with the teeth of the lower jaw. It also feeds on earthworms. Oviparous, like its congeners, its clutch size is unknown.

RELATED SPECIES

Sibon longifrenis appears similar to the recently described Costa Rican Snail-eater (Sibon lamari). Nine other snail-eaters occur in Costa Rica, five in Sibon, three in Dipsas, and Sartorius’ Terrestrial Snail-sucker (Tropidodipsas sartorii).

FAMILY	Dipsadidae: Dipsadinae
RISK FACTOR	Nonvenomous
DISTRIBUTION	Central America: Honduras, Nicaragua, Costa Rica, and Panama
ELEVATION	0–2,620 ft (0–800 m) asl
HABITAT	Low montane wet forest and rainforest
DIET	Slugs and snails, and possibly earthworms
REPRODUCTION	Oviparous, clutch size unknown
CONSERVATION STATUS	IUCN Least Concern

The Lichen Snail-eater has a laterally compressed body, a long tail, a broad head with protruding eyes, and catlike, vertically elliptical pupils. Its patterning consists of a complex green, brown, and gray lichen pattern with white spots on the lower flanks.

SIBON NEBULATUS
CLOUDY SNAIL-EATER

(LINNAEUS, 1758)

ADULT LENGTH
271/2–323/4 in (700–830 mm)

The Cloudy Snail-eater is the most widely distributed member of genus Sibon, occurring from southeastern Mexico to Ecuador, west of the Andes, and the Guianas east of the Andes. It occurs in a variety of low- to medium-elevation rainforest and wet forest habitats, but also inhabits dry forest, gallery forest along rivers, and secondary growth. In common with other Sibon snakes, this species is nocturnal and arboreal, and feeds on slugs and snails. Numerous snail-eaters have been found on trees hosting large arboreal snail populations, but they were found to be absent from trees lacking snails. This species is also thought to feed on tree frogs’ eggs. This is a commonly encountered snake that is also known to enter roof spaces in houses.

RELATED SPECIES

The genus Sibon contains 16 species of snail-eaters or snail-suckers, but none resemble Sibon nebulatus, the most widely distributed member of the genus. Its closest relatives are believed to be the Tegucigalpa Snail-eater (S. carri) from Honduras and El Salvador, and the Imbabura Snail-eater (S. dunni) from Ecuador, which together form the S. nebulatus group.

FAMILY	Dipsadidae: Dipsadinae
RISK FACTOR	Nonvenomous
DISTRIBUTION	North, Central, and South America: southeast Mexico to Brazil and Ecuador, the Guianas, Trinidad and Tobago, and Isla Margarita
ELEVATION	0–8,630 ft (0–2,630 m) asl
HABITAT	Low montane wet forest and rainforest, dry forest, gallery forest, and secondary growth
DIET	Slugs and snails, and possibly tree frogs’ eggs
REPRODUCTION	Oviparous, with clutches of 3–9 eggs
CONSERVATION STATUS	IUCN not listed

The Cloudy Snail-eater is a slender snake with a laterally compressed body, a long tail, a broad head, and protruding eyes with vertically elliptical pupils. It is gray in color with irregular light-edged, dark gray bands that continue under the venter, and dark speckling on the interspaces. Specimens may vary considerably.

SIBYNOMORPHUS NEUWIEDI
EASTERN SLUG-EATER

(IHERING, 1911)

ADULT LENGTH
193/4–271/2 in (500–700 mm)

The Eastern Slug-eater is found in southeastern Brazil from Bahia to Rio Grande do Sul, and also on the Ilhas São Sebastião and São Vicente. It inhabits the Atlantic coastal forests but is also found in disturbed and suburban areas. Unlike the genera Sibon and Dipsas, snakes in Sibynomorphus are terrestrial, or semi-arboreal, and feed on terrestrial slugs and snails. Slug- and snail-eaters are generally known as “goo-eaters.” They have specialized oral glands that secrete toxins to combat their prey’s secretions, which would otherwise gum up their mouths, but these oral secretions are not dangerous to humans and the snakes are inoffensive. Slug- and snail-eaters are known as “dormideiras,” or sleeping snakes, in Brazil. Maximilian Alexander Philipp, Prinz zu Wied-Neuwied (1782–1867) was a Prussian naturalist who explored Amazonia.

RELATED SPECIES

The genus Sibynomorphus contains 11 species of South American slug- or snail-eating snakes. Other Brazilian species include the White-collared Slug-eater (S. mikanii), the Southern Slug-eater (S. ventrimaculatus), and the Bolivian Slug-eater (S. turgidus).

FAMILY	Dipsadidae: Dipsadinae
RISK FACTOR	Nonvenomous
DISTRIBUTION	South America: southeastern Brazil
ELEVATION	0–2,100 ft (0–640 m) asl
HABITAT	Low montane wet forest and dry forest, also disturbed and suburban areas
DIET	Slugs and snails
REPRODUCTION	Oviparous, with clutch size unknown
CONSERVATION STATUS	IUCN not listed

The Eastern Slug-eater is a relatively stocky, laterally compressed, smooth-scaled snake with a broad head and small, protruding eyes with vertical pupils. It is pale brown with a pattern of broad, dark brown transverse bars that may or may not meet middorsally, but patterning may be variable.

SYNOPHIS BICOLOR
BICOLORED FISHING SNAKE

PERACCA, 1896

ADULT LENGTH
8–153/4 in, rarely 311/2 in (200–400 mm, rarely 800 mm)

The common name, “fishing snakes,” applied to snakes of the genus Synophis, is a misnomer, as none of the nine species described actually feed on fish. The diets of these snakes are poorly documented but seem to feature small lizards. The type species of the genus, the Bicolored Fishing Snake, occurs at low to medium elevations in Colombia, but authorities now believe that this species may actually constitute three similar but distinct species from the Ecuadorian Chocó, Ecuadorian Andes, and Colombian Andes. The first of these three forms inhabits lowland rainforest while the other two occur in Andean cloud forest. Specimens of all three have been found in low vegetation or leaf litter, and they are reportedly active by day and night.

RELATED SPECIES

The genus Synophis comprises nine species, one of which, the Valle de Cauca Fishing Snake (S. plectovertebralis), which was only described in 2001 from Colombia, is listed as Critically Endangered by the IUCN. Closely related genera include the terrier snakes (Emmochliophis) and the frog-eating snakes (Diaphorolepis).

FAMILY	Dipsadidae: Dipsadinae
RISK FACTOR	Nonvenomous
DISTRIBUTION	South America: Colombia
ELEVATION	655–5,580 ft (200–1,700 m) asl
HABITAT	Lowland rainforest and Andean cloud forest
DIET	Unknown but probably lizards
REPRODUCTION	Oviparous, with clutches of 2–8 eggs
CONSERVATION STATUS	IUCN not listed

The Bicolored Fishing Snake is a slender species with a laterally compressed body, keeled scales, a relatively broad head with bulbous eyes, round pupils, and a long tail. As its common name suggests it is two-tone, being brown above and bright yellow below.

TRETANORHINUS NIGROLUTEUS
ORANGE-BELLIED SWAMP SNAKE

COPE, 1861

ADULT LENGTH
Male
8–251/4 in (200–640 mm)

Female
223/4–353/4 in (575–900 mm)

The Orange-bellied Swamp Snake occurs at low and medium elevations from southeastern Mexico, through Central America, including the Honduran Islas de la Bahía and the Nicaraguan Corn Islands, and into Colombia. It can be very common in parts of its range but is reportedly a rare snake in Costa Rica. It is found in aquatic habitats, from freshwater streams and tree swamps to brackish mangrove forests, where it is nocturnally active. Prey consists of small fish, frogs, and their tadpoles, which may be actively hunted or ambushed by the snake lying in wait on the bottom of the watercourse. When resting the snake keeps its snout at the surface, ready to dive if danger threatens. Small specimens are taken by waders and other waterbirds.

RELATED SPECIES

Four subspecies are recognized by some authors, but they are poorly defined and are generally not accepted. Tretanorhinus also contains three other species, Mocquard’s Swamp Snake (T. mocquardi) in Panama and Ecuador, the Striped Swamp Snake (T. taeniatus) in Colombia and Ecuador, and the Caribbean Swamp Snake (T. variabilis) on Cuba and the Cayman Islands.

FAMILY	Dipsadidae: Dipsadinae
RISK FACTOR	Nonvenomous
DISTRIBUTION	North, Central, and South America: southeast Mexico, Guatemala, Belize, Honduras, Nicaragua, Costa Rica, Panama, and Colombia
ELEVATION	0–4,130 ft (0–1,260 m) asl
HABITAT	Lowland wet forest, tree swamps, freshwater streams, and mangrove forest
DIET	Fish, frogs, and tadpoles
REPRODUCTION	Oviparous, with clutches of 6–9 eggs
CONSERVATION STATUS	IUCN Least Concern

The Orange-bellied Swamp Snake is a glossy, smooth-scaled snake, with a long tail and a narrow but distinct head with small eyes. It is brown above and bright orange below, with the demarcation line along the lower flanks.

TRIMETOPON BARBOURI
CANAL ZONE GROUNDSNAKE

DUNN, 1930

ADULT LENGTH
8–113/4 in (200–300 mm)

The Canal Zone Groundsnake is endemic to Panama, including Barro Colorado Island. It was once believed confined to the Canal Zone, but is now known to be more widely distributed. The IUCN list this species as Vulnerable due to habitat loss. It is a semi-fossorial species that inhabits leaf litter in rainforest and secondary growth areas, but it is also found in gardens and agricultural plots. It is crepuscular in habit, but its prey preferences are unknown, although other members of the genus feed on salamanders and lizards so it may be expected to exhibit a similar diet. Likewise, it is thought to be oviparous with small clutch sizes, based on the data from congeners. Thomas Barbour (1884–1946) was an American zoologist with a specialist interest in Central America.

RELATED SPECIES

Genus Trimetopon contains five other leaf litter-dwelling species in Costa Rica and western Panama: the Cartago Groundsnake (T. gracile), San José Groundsnake (T. pliolepis), Reventazon Groundsnake (T. simile), Chiriquí Groundsnake (T. slevini), and Siquirres Groundsnake (T. viquezi).

FAMILY	Dipsadidae: Dipsadinae
RISK FACTOR	Nonvenomous
DISTRIBUTION	Central America: Panama
ELEVATION	0–3,610 ft (0–1,100 m) asl
HABITAT	Lowland rainforest, secondary regrowth, and gardens and agricultural patches
DIET	Probably salamanders and lizards
REPRODUCTION	Presumed oviparous, with clutches of 1–2 eggs
CONSERVATION STATUS	IUCN Vulnerable

The Canal Zone Groundsnake is a small snake with smooth scales, a slender body, a head indistinct from the neck, and moderate-sized eyes with round pupils. It is brown above with a pair of dark-edged, pale brown longitudinal stripes. The lower flanks are gray and the venter is white. A pair of pale spots are present on the neck in some specimens.

TROPIDODIPSAS SARTORII
SARTORIUS’ TERRESTRIAL SNAIL-SUCKER

COPE, 1863

ADULT LENGTH
Male
153/4–281/4 in (400–720 mm)

Female
153/4–34 in (400–860 mm)

Most snail-eating snakes are arboreal (Dipsas, and Sibon), but those in genus Tropidodipsas are primarily terrestrial. Sartorius’ Terrestrial Snail-sucker is the most widely distributed member of the genus, being found from southern Mexico to Costa Rica. It inhabits both wet and dry lowland tropical forest, gallery forest, wet premontane forest, and secondary growth, and is active nocturnally. It is also found in areas of secondary growth and is most abundant in limestone areas, entering caves and crevices in search of prey or shelter. It feeds exclusively on slugs and snails, which are subdued by the oral toxins of the snail-sucker, these secretions also combating the mucus produced by the mollusks. Christian Carl Wilhelm Sartorius (1796–1872) was a German naturalist who collected in Mexico.

RELATED SPECIES

Two subspecies of Tropidodipsas sartorii are recognized, a western or Mexico form (T. s. macdougalli) and an eastern or Central American form (T. s. sartorii). Six other Latin American species are known: the Western Snail-eater (T. annulifera), Banded Snail-eater (T. fasciata), Fischer’s Snail-eater (T. fischeri), Philippi’s Snail-eater (T. philippii), Sonoran Snail-eater (T. repleta), and Zweifel’s Snail-eater (T. zweifeli).

FAMILY	Dipsadidae: Dipsadinae
RISK FACTOR	Rear-fanged, mildly venomous; harmless to humans
DISTRIBUTION	North and Central America: Mexico, Guatemala, Belize, Honduras, El Salvador, Nicaragua, and Costa Rica
ELEVATION	0–8,010 ft (0–2,440 m) asl
HABITAT	Lowland dry and gallery forest, lowland and premontane wet forest, and secondary growth
DIET	Slugs and snails
REPRODUCTION	Oviparous, with clutches of 3–5 eggs
CONSERVATION STATUS	IUCN Least Concern

Sartorius’ Terrestrial Snail-sucker is a glossy, smooth-scaled snake with a long tail and a bulbous head with small, protruding eyes. It is black with well-spaced yellow bands, the first being across the rear of the head.

UROTHECA GUENTHERI
GÜNTHER’S BROWNSNAKE

(DUNN, 1938)

ADULT LENGTH
113/4–191/4 in, rarely 261/2 in (300–490 mm, rarely 670 mm)

Günther’s Brownsnake is found from northeastern Honduras to central Panama, at low and medium elevations in rainforest habitats, especially over limestone, where it feeds on frogs, salamanders, and lizards. This diurnal snake is secretive, hiding inside rotten logs or in leaf litter when it is not active. Members of the genus Urotheca have long tails, but many specimens are found with truncated tails due to their practice of caudal pseudautotomy as a defense against predation. This is a defense similar to the caudal autotomy practiced by lizards such as skinks and geckos. Unlike the lizard, snakes that practice pseudautotomy do not regenerate their lost tails. Albert Günther (1830–1914) was a German-born zoologist who worked in the British Museum of Natural History.

RELATED SPECIES

The genus Urotheca contains seven other species distributed from Honduras to Peru. Urotheca is related to graceful brownsnakes (Rhadinaea) and the false coralsnakes (Pliocercus).

FAMILY	Dipsadidae: Dipsadinae
RISK FACTOR	Rear-fanged, mildly venomous; harmless to humans
DISTRIBUTION	Central America: Honduras, Nicaragua, Costa Rica, and Panama
ELEVATION	0–6,890 ft (0–2,100 m) asl
HABITAT	Lowland and low montane wet and dry forest
DIET	Frogs, salamanders, and lizards
REPRODUCTION	Oviparous, with clutches of 3–5 eggs
CONSERVATION STATUS	IUCN Least Concern

Günther’s Brownsnake is a small, smooth-scaled snake with a very long, but often truncated, tail, a head only slightly distinct from the neck, and medium-sized eyes with round pupils. It is brown dorsally and orange ventrally, with a pair of fine yellow longitudinal stripes on either flank, the upper ones beginning as a pair of yellow nape spots.

ALSOPHIS SAJDAKI
GREAT BIRD ISLAND RACER

HENDERSON, 1990

ADULT LENGTH
233/4–301/2 in, rarely 3 ft 3 in (600–776 mm, rarely 1.0 m)

The Great Bird Island Racer is a former subspecies of the Antiguan Racer (Alsophis antiguae). It is one of the most endangered snakes in the world, the Antiguan population going extinct at the end of the nineteenth century following the accidental introduction of rats, and deliberate introduction of mongooses to control the rats. In 1995 the Great Bird Island population comprised 50–70 individuals. Conservation management measures, including rat eradication, captive breeding, and reintroduction to York, Green, and Rabbit Islands, have raised the wild racer population to over 1,000 individuals. Harmless to humans, these diurnally active racers inhabit low-lying rocky scrubland and prey on lizards and mice, ambushed from cover in the leaf litter. This species is still Critically Endangered according to the IUCN. Richard A. Sajdak is an American herpetologist.

RELATED SPECIES

In addition to Alsophis antiguae and A. sajdaki, the genus Alsophis contains a further seven species of Antillean racers. These include the Guadeloupe Racer (A. antillensis), Dominican Racer (A. sibonius), Montserrat Racer (A. manselli), Terre-de-Bas Racer (A. danforthi), Terre-de-Haut Racer (A. sanctonum), Anguilla or Leeward Island Racer (A. rijgersmaei), and Orange-bellied Saba Racer (A. rufiventris). The last three of these are also listed as Endangered by the IUCN.

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous; harmless to humans
DISTRIBUTION	West Indies: Great Bird Island (Antigua)
ELEVATION	0–98 ft (0–30 m) asl
HABITAT	Open, dry, rocky scrubland
DIET	Lizards and small mammals
REPRODUCTION	Oviparous, with clutches up to 11 eggs (based on two females)
CONSERVATION STATUS	IUCN Critically Endangered, as A. antiguae

The Great Bird Island Racer is a smooth-scaled snake with a slightly elongate, pointed head, and small eyes with round pupils. This species is sexually dichromatic, males being dark brown with cream markings while females are silver-gray with pale brown markings. Specimens may be blotched, striped, or spotted. Females also possess larger heads than males and achieve slightly larger overall sizes.

APOSTOLEPIS AMMODITES
TWIN-COLLARED CERRADO SANDSNAKE

FERRAREZZI, ERRITTO BARBO & ESPAÑA ALBUQUERQUE, 2005

ADULT LENGTH
173/4–25 in (450–634 mm)

No common English name exists for snakes of the genus Apostolepis, so Twin-collared Cerrado Sandsnake is coined to combine its most distinctive characteristic, two white rings around the neck, with its distribution and habitat preferences. It is found in the arid sandy habitat known as Cerrado, which occurs across a wide swath of central and northeastern Brazil, where it adopts a primarily fossorial existence in the sandy soil. The only prey recorded from the guts of museum specimens have been amphisbaenians, or worm-lizards, a group of similarly fossorial reptiles considered distinct from other lizards. Twin-collared Cerrado Sandsnakes may be rear-fanged and venomous, but they have extremely small mouths. Even so, there are snakebites on record from A. dimidiata, which has a hemorrhagic venom, and caution is recommended with any unusual snake species.

RELATED SPECIES

The genus Apostolepis contains 33 species. Apostolepis ammodites belongs to the A. assimilis group, which may contain five other species, A. assimilis from southeastern and central Brazil, Paraguay and Argentina, A. cearensis from Ceará, Brazil, A. arenaria and A. gaboi from Bahia, Brazil, and A. quirogai from Rio Grande do Sul, Brazil and Misiones, Argentina.

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, venomous: possibly hemorrhagins
DISTRIBUTION	South America: central and northeastern Brazil
ELEVATION	755–2,820 ft (230–860 m) asl
HABITAT	Open Cerrado on sandy soils
DIET	Amphisbaenians
REPRODUCTION	Oviparous, with clutches of up to 3 eggs
CONSERVATION STATUS	IUCN Data Deficient

The Twin-collared Cerrado Sandsnake is an extremely slender, elongate snake with smooth scales, a narrow head that is indistinct from the neck, small eyes, and a shovel-shaped snout for burrowing. Like many of its congeners it is red in color with a black tail tip and a series of black and white rings around the head and neck, but it differs from its relatives in possessing two broad white rings, rather than a single white collar.

ARRHYTON TAENIATUM
BROAD-STRIPED RACERLET

GÜNTHER, 1858

ADULT LENGTH
153/4–18 in (400–460 mm)

Secretive, semi-fossorial to fossorial, and probably nocturnal based on its vertical pupils, this small snake is rarely encountered unless it is excavated from the earth by a plow or found sheltering under a flat stone. It is believed more fossorial in its habits than some of its long-tailed congeners, which are more terrestrial and less adapted for burrowing. It inhabits open grassland and pasture, especially areas with large stones or rocks, and is recorded from eastern, western, and southern Cuba, and Isla de la Juventud. The prey of the Broad-striped Racerlet comprises other fossorial reptiles, such as amphisbaenians (commonly known as worm- lizards), blindsnakes (Typhlopidae), and threadsnakes (Leptotyphlopidae). The Cuban racerlets are poorly known, with very few ecological observations documented.

RELATED SPECIES

The genus Arrhyton contains eight species of Cuban racerlets, but only the equally widely distributed Cuban Short-tailed Racerlet (A. vittatum) also occurs on the Isla de la Juventud. These species can be distinguished on the presence (A. vittatum) or absence (A. taeniatum) of a loreal scale, between the preocular and nasal scales, and by the longer tail of A. vittatum. The remaining species are much more localized in their distribution on the Cuban mainland.

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Probably rear-fanged, mildly venomous
DISTRIBUTION	West Indies: Cuba, including Isla de la Juventud
ELEVATION	0–330 ft (0–100 m) asl
HABITAT	Open grasslands and rocky pasture
DIET	Amphisbaenians and small snakes
REPRODUCTION	Presumed oviparous, but unknown
CONSERVATION STATUS	IUCN Least Concern

The Broad-striped Racerlet is a small, smooth-scaled snake with a slightly pointed and compressed head that is just distinct from the neck, small eyes with vertically elliptical pupils, a pattern comprising two pale longitudinal dorsolateral stripes on a mahogany background, and a yellow venter.

BOIRUNA MACULATA
BLACK-TAILED MUSSURANA

(BOULENGER, 1896)

ADULT LENGTH
5–6 ft (1.5–1.8 m)

The Black-tailed Mussurana inhabits a wide range of different environments from southeastern Brazil to Paraguay, Bolivia, Uruguay, and Argentina. It is found in wet coastal forests and dry Chaco woodlands and even occurs in arid elevated desert habitats. This is a species that goes through a considerable ontogenetic color change from juvenile to adult. The generic name Boiruna is derived from a Tupi-Guarani term, “Mboi-r-ú,” which means “eats snakes.” Mussuranas are ophiophagous species that prey primarily on other species, including highly venomous lanceheads of genus Bothrops (shown here). They are immune to the pitvipers’ bites. Lizards and small mammals are also taken. Bites to humans have caused localized pain and swelling similar to bites from lanceheads, although much less serious. However, bites from large specimens to children may be life-threatening.

RELATED SPECIES

The genus Boiruna contains a second species, the Sertão Mussurana (B. sertaneja), from the open xeric habitats of northeastern Brazil. Several other genera of mussuranas also occur in South America, including Clelia (shown here), Mussurana (shown here), and Paraphimophis (shown here). Adult B. maculata can be distinguished from most other mussuranas within their range by the black pigment on the underside of the posterior body and tail. Closely related genera include the Brazilian Birdsnake (Rhachidelus brazili) and the scarlet snakes (Pseudoboa).

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, venomous: possibly cytotoxins, composition unknown
DISTRIBUTION	South America: southeast Brazil, east Bolivia, Paraguay, Uruguay, and Argentina
ELEVATION	98–2,890 ft (30–880 m) asl
HABITAT	Wet Atlantic forests, dry Chaco woodland, and arid desert
DIET	Snakes, lizards, and small mammals
REPRODUCTION	Oviparous, with clutches of 4–15 eggs
CONSERVATION STATUS	IUCN not yet assessed

The Black-tailed Mussurana is a large, smooth-scaled snake with a relatively large head and moderately large eyes. Juveniles are black on the dorsum of the head with a white, yellow, or red nape band behind and a broad black vertebral stripe. The remainder of the dorsal scales are red with black tips, the undersides and lips being white. Adults are much darker, the black pigment overwhelming all other dorsal patterns.

BORIKENOPHIS PORTORICENSIS
PUERTO RICAN RACER

(REINHARDT & LÜTKEN, 1862)

ADULT LENGTH
2 ft 7 in–3 ft 3 in (0.8–1.0 m)

The Puerto Rican Racer is found in Puerto Rico and the US and British Virgin islands. It is diurnally active in habitats ranging from rainforest to pastures and plantations. It may be found on beaches or under human trash, but is an early morning snake that is rarely seen after 10 a.m. Although terrestrial it is also highly agile and has been found up to 245 ft (75 m) from the ground in rainforest trees. It preys on lizards, frogs, and smaller snakes, which are killed by its hemolytic and hemorrhagic venom (see shown here), although prey often has to be restrained with the coils while the venom takes effect. Bites to humans have caused severe but not life-threatening results. There are no highly venomous snakes on Puerto Rico or the Virgin Islands.

RELATED SPECIES

There are six recognized subspecies of Borikenophis portoricensis. The nominate form and one other subspecies (B. p. prymnus) occur on Puerto Rico, while other subspecies are found on Isla de Vieques (B. p. aphantus), Isla Culebra and St. Thomas (B. p. richardi), Buck Island, off St. Thomas (B. p. nicholsi), and Anegada and the British Virgin Islands (B. p. anegadae). The genus Borikenophis contained two other species, the Isla Mona Racer (B. variegatus), and the St. Croix Racer (B. sanctaecrucis), from the US Virgin Islands, but now listed as Extinct by the IUCN.

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, venomous: hemotoxins and hemorrhagins
DISTRIBUTION	West Indies: Puerto Rico, and the US and British Virgin islands
ELEVATION	0–1,480 ft (0–450 m) asl
HABITAT	Rainforest, open pasture, rocky hillsides, coconut plantations and groves, gardens, mangrove swamps, and beaches
DIET	Lizards, frogs, and snakes
REPRODUCTION	Oviparous, with clutches of 4–10 eggs
CONSERVATION STATUS	IUCN not yet assessed

The Puerto Rican Racer is a slender, long-tailed snake with a long, pointed head, slightly distinct from the neck, and large eyes with round pupils. It may be variably patterned, depending on which island it originated from, but commonly it is brown or gray above with fine black longitudinal stripes and pale gray to white below and on the lips. A black stripe may pass from the snout, through the eye.

CARAIBA ANDREAE
CUBAN BLACK AND WHITE RACER

(REINHARDT & LÜTKEN, 1862)

ADULT LENGTH
153/4–193/4 in (400–500 mm)

Also known as the Cuban Lesser Racer, this is one of the most widely distributed Cuban snakes. The Cuban Black and White Racer is found throughout mainland Cuba, the Isla de la Juventud, and the smaller cays off the north and south coasts. This snake is an inhabitant of palm forest, coastal scrub, and brackish lagoons, but it is also found in agricultural areas and will enter houses. It is terrestrial, diurnally active, and highly alert, hunting frogs and lizards, and using a burst of speed to escape predators. It is also sometimes fossorial as specimens have been turned up by plows. Captain F. Andréa was the Danish sea captain who collected the original type series for the Copenhagen Museum.

RELATED SPECIES

Although Caraiba andreae is a monotypic species, it does contain six subspecies, three from mainland Cuba and three from the Isla de la Juventud, the Cayo Cantiles, and the Cayos Santa María and Guajaba. Its closest relative is the Hispaniolan Racer (Haitiophis anomalus), which some authors also place in Caraiba. Both these species are related to the Greater Antillean racers (Cubophis).

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Nonvenomous
DISTRIBUTION	West Indies: Cuba, including Isla de la Juventud
ELEVATION	0–330 ft (0–100 m) asl
HABITAT	Palm forest, coastal scrub, dry scrub, wooded areas, brackish lagoons, pastures, fields, and houses
DIET	Frogs and lizards
REPRODUCTION	Oviparous, with clutches of up to 3 eggs
CONSERVATION STATUS	IUCN Least Concern

The Cuban Black and White Racer is a small, smooth-scaled snake with a distinctive head, large eyes with round pupils, and a long tail. Although variable, it is often black above with occasional white spots, while the black scales of the flanks are heavily marked with white and the undersides and lips are white with black suturing.

CLELIA CLELIA
COMMON MUSSURANA

(DAUDIN, 1803)

ADULT LENGTH
Male
3 ft 3 in–6 ft (1.0–1.8 m)

Female
5 ft–8 ft 6 in (1.5–2.6 m)

Also known as the Ratonera, this is a widely distributed mussurana, found from Belize and Guatemala to Trinidad, and south to northeastern Argentina. It occurs in lowland habitats, from pristine rainforest to secondary growth, and is encountered in human-mediated habitats, along ditches or roads, or around buildings, where it hunts its primary prey, sympatric pitvipers (Atropoides; Bothrops; Porthidium) and rattlesnakes (Crotalus). Mussuranas are immune to the bites of their quarry species. They also prey on lizards and small mammals. Following an initial venomous bite to the neck, the Common Mussurana will also use constriction to subdue its prey. It is generally inoffensive, and does not bite if handled, but caution is advised, as it is a large snake. Females are larger than males.

RELATED SPECIES

The Common Mussurana is represented by two subspecies, the nominate form inhabiting most of the range, with an island endemic (C. c. groomei) on Grenada in the Lesser Antilles. The genus Clelia also contains six other species of mussuranas. Reports of Clelia clelia from southern Mexico refer to the Mexican Mussurana (C. scytalina), while those from St. Lucia refer to the endemic St. Lucia Mussurana (C. errabunda). Other related genera of South American mussuranas include Boiruna (shown here), Mussurana (shown here), and Paraphimophis (shown here).

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, venomous, also constrictor
DISTRIBUTION	Central and South America: Belize and Guatemala, to Trinidad and Lesser Antilles, and south to northwest Argentina
ELEVATION	0–8,200 ft (0–2,500 m) asl
HABITAT	Lowland forests, secondary growth, cultivated areas, and along ditches and roads
DIET	Snakes, lizards, and small mammals
REPRODUCTION	Oviparous, with clutches of 10–22 eggs
CONSERVATION STATUS	IUCN not yet assessed, CITES Appendix II

The Common Mussurana is a large, powerful snake with a stout body, glossy, smooth scales, and a large head with small eyes and round pupils. Adults are gunmetal gray above, without markings, and white below, while juveniles are red above and white below, with a black head and a broad yellow or cream neck band, followed by a dorsal black patch. The juvenile resembles juveniles of the scarlet snakes (Pseudoboa) and adult coffee snakes (Ninia).

CONOPHIS LINEATUS
CENTRAL AMERICAN ROAD GUARDER

(DUMÉRIL, BIBRON & DUMÉRIL, 1854)

ADULT LENGTH
3 ft–3 ft 10 in (0.7–1.16 m)

The Central American Road Guarder is the most widely distributed member of the genus Conophis, occurring from central Mexico to Costa Rica. It inhabits savanna grassland, dry tropical forest, beaches, and wet tropical forest, and is both terrestrial and arboreal. As a “road guarder,” a snake that predates other snakes, it often preys on highly venomous sympatric coralsnakes (Micrurus), but its prey consists primarily of lizards, hence the alternative name “lizard killer.” Small mammals, birds, and frogs are also taken. The long rear fangs inject fairly toxic venom. This is an irascible species that will bite readily if handled. Given that snakebite victims report an intense painful burning sensation and swelling, widespread tingling, and prolonged bleeding from the bite site, road guarders should be considered potentially dangerous and treated with caution.

RELATED SPECIES

The genus Conophis also contains four localized species, treated as synonyms of subspecies by some authors: the Yucatan Road Guarder (C. concolor), a former unicolor subspecies of C. lineatus; the Tuxtlas Road Guarder (C. morai); the Southwest Mexican Road Guarder (C. vittatus); and the Beautiful Road Guarder (C. pulcher) from Chiapas, Guatemala, and El Salvador. Nevermann’s Road Guarder (Crisantophis nevermanni), from Guatemala to Costa Rica, was also once included in Conophis.

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous: possibly anticoagulants; potentially dangerous
DISTRIBUTION	North and Central America: Mexico, Guatemala, El Salvador, Honduras, Nicaragua, and Costa Rica
ELEVATION	0–4,920 ft (0–1,500 m) asl
HABITAT	Dry savannas, beaches, dry tropical forest, roads, and open areas in wet tropical forest
DIET	Lizards, snakes, frogs, and small mammals or birds
REPRODUCTION	Oviparous, with clutches of 5–10 eggs
CONSERVATION STATUS	IUCN Least Concern

The Central American Road Guarder is a smooth-scaled snake with a narrow head, a pointed snout, moderately large eyes, round pupils, and a long tail. It may be brown or olive and it is patterned dorsally with a series of light and dark longitudinal stripes, although the color, width, and number of these stripes varies. The throat and belly are immaculate white.

CRISANTOPHIS NEVERMANNI
NEVERMANN’S ROAD GUARDER

(DUNN, 1937)

ADULT LENGTH
233/4–321/2 in (600–828 mm)

Nevermann’s Road Guarder is found along the Pacific versant of Central America from Guatemala to Costa Rica, and on the Atlantic versant in Nicaragua. It inhabits dry lowland forest but has also been found in submontane wet forest. Although it is called a “road guarder,” a snake that eats other snakes, it primarily takes frogs and lizards, but snakes are also eaten, including smaller specimens of its own species. It uses a combination of venom and constriction to subdue its prey. The effects of a bite to a human are unknown and, as with other “unknown” rear-fanged snakes, caution is recommended. Often called Dunn’s Road Guarder, this species was described by Dunn in honor of his German coleopterist friend Wilhelm Nevermann (1881–1938).

RELATED SPECIES

The monotypic genus Crisantophis is possibly most closely related to the Central American Road Guarder (Conophis lineatus), but it is considered incertae sedis (of unknown status) within the Dipsadinae by some authors.

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous
DISTRIBUTION	Central America: Guatemala, El Salvador, Honduras, Nicaragua, and Costa Rica
ELEVATION	0–4,580 ft (0–1,395 m) asl
HABITAT	Lowland dry forest and submontane wet forest, especially along streams, lakes, and rice paddies
DIET	Frogs, toads, and small snakes, including cannibalism
REPRODUCTION	Oviparous, with clutches of up to 10 eggs
CONSERVATION STATUS	IUCN Least Concern

Nevermann’s Road Guarder is a smooth-scaled, relatively slender snake with an elongate head, moderately large eyes, and a long tail. It is black above with a series of four fine yellow longitudinal stripes, the lower stripes being twice the width of the upper stripes, and a yellow to cream venter.

CUBOPHIS CANTHERIGERUS
CUBAN RACER

(BIBRON, 1840)

ADULT LENGTH
3 ft–4 ft 3 in (0.95–1.3 m)

A widespread species, the Cuban Racer is found throughout Cuba in many different habitats, from beaches and mangrove swamps to fields and scrubby hillsides. It is also found close to human habitations and may be found sheltering under human trash. It is an active predator of frogs, lizards, snakes, birds, bats, and rodents, but its venom is weak so it also relies on constriction to subdue its prey. There are no accounts of bites to humans, but caution is recommended when handling any rear-fanged species of a reasonable size. Although primarily a terrestrial, diurnal snake, which may be seen dashing about after prey, it has also been observed to be active at night.

RELATED SPECIES

There are four subspecies of Cubophis cantherigerus distributed throughout mainland Cuba, on Isla de la Juventud, and on small islands and cays (low banks) around the coast. The Greater Antillean racer genus Cubophis also contains five other species: the Swan Island Racer (C. brooksi), Grand Cayman Racer (C. caymanus), Cayman Brac Racer (C. fuscicauda), and Little Cayman Racer (C. ruttyi), all former subspecies of C. cantherigerus, and the Bahamian Racer (C. vudii). Closely related taxa are the Cuban Black and White Racer (Caraiba andreae) and the Hispaniolan Racer (Haitiophis anomalus).

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous
DISTRIBUTION	West Indies: Cuba, including Isla de la Juventud
ELEVATION	0–985 ft (0–300 m) asl
HABITAT	Hillsides, scrubland, beaches, pasture, wooded areas, mangrove swamps, and around human habitations
DIET	Frogs, lizards, snakes, birds, and small mammals
REPRODUCTION	Oviparous, with clutches of 10–24 eggs
CONSERVATION STATUS	IUCN not yet assessed

The Cuban Racer is a smooth-scaled snake with an elongate head, large eyes with round pupils, and a long tail. It is variably patterned, but many specimens are gray to light brown with dark suturing around every scale, presenting a reticulate effect. A black cap is often present on the posterior of the head, and dark postocular stripes are also present.

DREPANOIDES ANOMALUS
LIZARD EGG-EATING SNAKE

(JAN, 1863)

ADULT LENGTH
153/4–211/4 in (400–540 mm)

The Lizard Egg-eating Snake is a western Amazonian species found in southern Colombia, western Brazil, eastern Ecuador, Peru, and northern Bolivia, but it is also reported from the Guianas in the northeast. It is a nocturnal, forest-floor species that is usually found in clearings or along trails, where it forages for lizard eggs, its only documented diet. It has also been reported to be both semi-fossorial and semi-arboreal. This is a small snake, and females only lay two or three eggs. This species may easily be mistaken for a juvenile mussurana (Clelia) or scarlet snake (Pseudoboa), with which it occurs in sympatry, and from which it can be distinguished by the lack of a loreal scale. Although rear-fanged and venomous it is not thought to be dangerous to humans.

RELATED SPECIES

The genus Drepanoides is monotypic, and closely related to the snake-eating mussuranas (Boiruna; Clelia; Mussurana; and Paraphimophis).

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous
DISTRIBUTION	South America: Colombia, Ecuador, Brazil, Peru, Bolivia, and the Guianas
ELEVATION	165–1,640 ft (50–500 m) asl
HABITAT	Rainforest clearings or trails
DIET	Lizard eggs
REPRODUCTION	Oviparous, with clutches of 2–3 eggs
CONSERVATION STATUS	IUCN not yet assessed

The Lizard Egg-eating Snake is a small, smooth-scaled snake with a head slightly distinct from the neck, small eyes, and a long tail that is often truncated. It is bright red with black scale tips, which provides a reticulate effect, and a glossy black head, with a white cream band across the black nape collar, which extends forward onto the lips.

ECHINANTHERA CYANOPLEURA
YELLOW-BELLIED FOREST SNAKE

(COPE, 1885)

ADULT LENGTH
233/4–311/2 in (600–800 mm)

First described from a holotype collected at São Joao de Montenegro in Rio Grande do Sul, southeastern Brazil, this species is now known to occur as far north as Rio de Janeiro and as far south as Misiones, Argentina. It is primarily an inhabitant of the threatened Atlantic coastal forests, but has also been found farther inland. Its prey consists of frogs and possibly small lizards. It is a diurnal species that inhabits leaf litter on the forest floor, and it is rarely encountered at night. Females are oviparous but the clutch size is unknown. If disturbed this nonvenomous snake defends itself by body-flattening and expelling the foul-smelling contents of its cloacal glands.

RELATED SPECIES

There are five other species in the genus Echinanthera, distributed from Bahia to Rio Grande do Sul in eastern Brazil and into Uruguay and northeast Argentina, although the Undulated Forest Snake (E. undulata) is found in southeastern Colombia. The most similar species is the Line-headed Forest Snake (E. cephalostriata). The closest related genus is another leaf-litter genus, Taeniophallus (shown here).

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Nonvenomous
DISTRIBUTION	South America: southeastern and southern Brazil, and northern Argentina
ELEVATION	1,670–3,360 ft (510–1,025 m) asl
HABITAT	Atlantic coastal forests
DIET	Frogs, and possibly lizards
REPRODUCTION	Oviparous, clutch size unknown
CONSERVATION STATUS	IUCN not yet assessed

The Yellow-bellied Forest Snake is a small, smooth-scaled snake with a long tail and a head slightly distinct from the neck, with moderately large eyes and round pupils. It is brown above, darker on the flanks than the dorsum, with pale punctuated longitudinal stripes. The undersides are yellow, as is a broken collar around the neck, but the lips are white.

ELAPOMORPHUS QUINQUELINEATUS
FIVE-LINED BURROWING SNAKE

(RADDI, 1820)

ADULT LENGTH
1 ft 8 in–3 ft 3 in (0.5–1.0 m)

The Five-lined Burrowing Snake is a rare leaf-litter inhabitant of southeastern Brazilian lowland rainforest, from southern Bahia to Rio Grande do Sul. Adults prey on amphisbaenians, (also known as worm-lizards) and small snakes, while juveniles eat earthworms. The commonly used name, Raddi’s Lizard-eating Snake, seems inappropriate given this diet. Although known to be oviparous, its clutch size is unknown. This is a diurnal, terrestrial, or fossorial species that shelters under logs or in litter-filled tree buttresses. If handled it will thrash about violently, expel its cloacal gland contents, and may bite. The venom has not been studied, but despite the relatively small size of its head this snake should be treated with caution because Elapomorphus is closely related to the genus Phalotris (shown here), which has caused a life-threatening snakebite.

RELATED SPECIES

The genus Elapomorphus contains a second species, Wucherer’s Burrowing Snake (E. wuchereri) from Bahia and Espírito Santo, eastern Brazil. Genera related to Elapomorphus include Phalotris (shown here) and Apostolepis (shown here).

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, venomous; potentially dangerous
DISTRIBUTION	South America: southeastern Brazil
ELEVATION	0–1,150 ft (0–350 m) asl
HABITAT	Lowland and coastal forests
DIET	Earthworms, amphisbaenians, and small snakes
REPRODUCTION	Oviparous, clutch size unknown
CONSERVATION STATUS	IUCN not yet assessed

The Five-lined Burrowing Snake is a smooth-scaled snake with a short tail, a narrow head that is indistinct from the neck, and small eyes with round pupils. It is brown above and yellow on the flanks and undersides, with a yellowish collar around the neck and five dark brown longitudinal stripes.

ERYTHROLAMPRUS AESCULAPII
AESCULAPIAN FALSE CORALSNAKE

(LINNAEUS, 1758)

ADULT LENGTH
251/2–311/2 in (650–800 mm)

The Aesculapian False Coralsnake is a common Amazonian coralsnake mimic found throughout most of northern South America, east of the Andes, including Trinidad. It occurs as far south as northeastern Argentina. Across its extensive range it demonstrates a variation of tricolor banded patterns to match the coralsnakes (Micrurus) within its range, but it differs from true coralsnakes by possessing a loreal scale. The Aesculapian False Coralsnake is a forest-floor species that inhabits leaf litter in primary rainforest habitats, often being found along trails or in freshly cleared plots. It preys on other snakes, amphisbaenians (worm-lizards), and lizards, which it kills with a venomous bite, but it is not believed to possess venom toxic enough to affect humans. Caution is recommended with any coralsnake mimic, in case it isn’t a mimic.

RELATED SPECIES

Erythrolamprus aesculapii is represented by four subspecies, the nominate form in the Amazon, and subspecies in the Brazilian Atlantic forests (E. a. monozona), Bolivia (E. a. tetrazona), and southeastern Brazil to Argentina (E. a. venustissimus). Until relatively recently the genus Erythrolamprus contained only five other species, but it has been greatly expanded, with the inclusion of many species formerly in Liophis. There are now 50 species in the genus Erythrolamprus.

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous
DISTRIBUTION	South America: Colombia to Trinidad and northeast Argentina
ELEVATION	0–7,550 ft (0–2,300 m) asl
HABITAT	Rainforest
DIET	Other snakes, amphisbaenians, and lizards
REPRODUCTION	Oviparous, with clutches of up to 5 eggs
CONSERVATION STATUS	IUCN not yet assessed

The Aesculapian False Coralsnake is a smooth-scaled snake with a narrow head, only slightly distinct from the neck, a rounded, white-tipped snout, and moderately large eyes with round pupils. A tricolor snake, it is banded black-white-black, including over the head, with broad red interspaces, although older animals are more melanistic. White and red scales are black-tipped. There are geographical variations in this pattern to match the local coralsnakes.

ERYTHROLAMPRUS REGINAE
ROYAL GROUNDSNAKE

(LINNAEUS, 1758)

ADULT LENGTH
133/4–213/4 in, rarely 271/2 in (350–550 mm, rarely 700 mm)

Also sometimes referred to as the Common Swamp Snake, this is a widely distributed and frequently encountered American snake that occurs from Colombia to northern Argentina. It inhabits both primary and secondary rainforest and also cultivated gardens and cultivated plots, but is usually associated with wetlands. Its preference is for shallow watercourses with abundant littoral or floating vegetation. Prey consists of frogs, geckos, and the microteiid lizards that also occupy aquatic habitats and low vegetation into which the snake may climb. Some relatives of the Royal Groundsnake are known to possess toxic saliva containing an anticoagulant, but whether it would have any effect on humans is unknown. Its defense involves neck-flattening to expose the contrasting orange and blue interstitial skin, but this snake is generally inoffensive. The name reginae means “royal.”

RELATED SPECIES

Erythrolamprus reginae was formerly in the genus Liophis, along with 42 other species now synonymized within the genus Erythrolamprus. Three subspecies of E. reginae are recognized, the nominate northern South American form (E. r. reginae), an Amazonian and Atlantic coastal form (E. r. semilineatus), and a southern Brazilian, Paraguayan, and northern Argentinian form (E. r. macrosoma). The Military Groundsnake (E. miliaris) is a close relative of E. reginae.

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous; may contain an anticoagulant
DISTRIBUTION	South America: Colombia to the Guianas and Trinidad, and south to northern Argentina
ELEVATION	0–9,840 ft (0–3,000 m) asl
HABITAT	Rainforest, secondary growth, and cultivated areas, usually near water
DIET	Frogs and lizards
REPRODUCTION	Oviparous, with clutches of 1–6 eggs
CONSERVATION STATUS	IUCN not yet assessed

The Royal Groundsnake is a smooth-scaled snake with a rounded head, large eyes, and round pupils. It is brown or olive-green above with a speckling of yellow and black. The undersides are checkerboarded with black and either yellow or red.

GOMESOPHIS BRASILIENSIS
BRAZILIAN BALLSNAKE

(GOMES, 1918)

ADULT LENGTH
113/4–193/4 in (300–500 mm)

The Brazilian Ballsnake is confined to the southeastern states of Brazil, from Minas Gerais to Rio Grande do Sul. It is terrestrial to semi-aquatic, inhabiting shallow watercourses and gallery forest, and is most often found burrowing in muddy substrates in these habitats. This species is believed to feed exclusively on earthworms and is a member of a guild of snakes known as “goo-eaters”—feeders on earthworms, slugs, or snails. Although a rear-fanged venomous species, the Brazilian Ballsnake is so named because its primary defense is to roll into a defensive ball in the same manner as the Ball Python (Python regius), Northern Rubber Boa (Charina bottae), and Asian pipesnakes (Cylindrophis). It is unusual within the Xenodontinae in being live-bearing, which is probably an aquatic adaptation.

RELATED SPECIES

This species was originally described as Tachymenis brasiliensis by the Brazilian herpetologist João Florêncio Gomes (1886–1919), before being transferred to the newly created monotypic genus Gomesophis in 1959. Gomesophis is closely related to the scrub snakes (Tachymenis), the pampas snakes (Tomodon), and the mock vipers (Thamnodynastes).

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous
DISTRIBUTION	South America: southeastern Brazil
ELEVATION	1,820 ft (555 m) asl
HABITAT	Gallery forest and watercourses over muddy substrates
DIET	Earthworms
REPRODUCTION	Viviparous, litter size unknown
CONSERVATION STATUS	IUCN not yet assessed

The Brazilian Ballsnake is a glossy, smooth-scaled snake with a narrow, pointed head that is indistinct from the neck, small eyes, and a short tail. It is light brown above, often with either broad or fine brown longitudinal stripes, and dark brown on the flanks.

HELICOPS ANGULATUS
BANDED KEELED WATERSNAKE

(LINNAEUS, 1758)

ADULT LENGTH
233/4–311/2 in, rarely 3 ft 4 in (600–800 mm, rarely 1.02 m)

The Banded Keeled Watersnake is an inhabitant of slow-moving rivers and heavily vegetated marshes and swamps throughout northern South America, from Colombia, east to Trinidad, and south to Bolivia, and Goiás in central Brazil. It is nocturnal and semi-aquatic and preys on fish, frogs, and occasionally the lizards associated with aquatic habitats. Giant earthworms are also included in its diet when other prey is less abundant. Although generally inoffensive, this species can be truculent if disturbed, flattening its body in defense and voiding the contents of its cloacal glands if handled. It may also bite easily, with bites causing localized inflammation, swelling, and pain, but it is not considered dangerous to humans. Large females may lay up to 20 eggs in a single clutch.

RELATED SPECIES

The genus Helicops is the equivalent of the North American watersnake or keelback genus Nerodia (shown here), albeit in a different family. The genus contains 17 other species, with the Spotted Keeled Watersnake (H. leopardinus) occurring in sympatry with H. angulatus through much of its range. The São Paulo Keeled Watersnake (H. gomesi) is a close relative of H. angulatus.

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous
DISTRIBUTION	South America: Colombia to Trinidad, south to Brazil and Bolivia
ELEVATION	0–7,910 ft (0–2,410 m) asl
HABITAT	Slow rivers, grassy marshes, swamps
DIET	Fish, frogs, lizards, and earthworms
REPRODUCTION	Oviparous, with clutches of 4–20 eggs
CONSERVATION STATUS	IUCN not yet assessed

The Banded Keeled Watersnake is a small snake with strongly keeled scales, a short tail, and a moderately broad head, with small, dorsolaterally positioned eyes and round pupils. Patterning comprises irregular dark or reddish bands on a light brown background. The bands may continue onto the cream, gray, orange, or red belly. The subcaudal scales are also keeled.

HELICOPS LEOPARDINUS
SPOTTED WATERSNAKE

(SCHLEGEL, 1837)

The Spotted Watersnake is an inhabitant of slow-moving rivers, small quiet ponds, and heavily vegetated marshes and swamps, especially those with floating littoral vegetation, throughout northern South America, from the Guianas and Brazil, where it is common and widely distributed, as far south as the Rio Parana region of Argentina. It is nocturnal and semi-aquatic in habit, preying on frogs and fish. Although generally inoffensive all members of this genus will bite if handled, with bites causing localized inflammation, swelling and pain, but these watersnakes are not considered dangerous to humans. The Spotted Watersnake is viviparous, with litters of 7–31 neonates, in contrast to its congener, Helicops angulatus, which lays eggs.

RELATED SPECIES

The genus Helicops contains 18 species. Helicops leopardinus occurs in sympatry with the South American Banded Keeled Watersnake (H. angulatus) across much of its range, especially in Brazil, although the two species differ in their reproductive strategy.

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous
DISTRIBUTION	South America: the Guianas and Brazil to northern Argentina
ELEVATION	0–7,910 ft (0–2,410 m) asl
HABITAT	Slow rivers, small ponds, and grassy marshes and swamps
DIET	Frogs and fish
REPRODUCTION	Viviparous, with litters of 7–31 neonates
CONSERVATION STATUS	IUCN not listed

The Spotted Watersnake is a small snake with strongly keeled scales, a short tail, and a moderately broad head, distinct from the neck, with small, dorsolaterally positioned eyes and round pupils. The dorsal patterning consists of four rows of dark spots on a gray background, some of the spots being occasionally connected by narrow bands, while the undersides exhibit a checkerboard of red and black posteriorly and white and black anteriorly.

HYDRODYNASTES GIGAS
GIANT FALSE WATER COBRA

(DUMÉRIL, BIBRON & DUMÉRIL, 1854)

ADULT LENGTH
6 ft 7 in–9 ft, possibly up to 10 ft (2.0–2.7 m, possibly up to 3.0 m)

Called a “false cobra” because of its ability to spread a narrow, cobra-like hood when threatened, albeit horizontally and not vertically, this is a popular species in collections. It is a large, showy, diurnal snake, but not one without problems as people respond in different ways to its bites, some experiencing no symptoms but others suffering gross swelling and localized pain. As a large, rear-fanged venomous snake it demands respect. It inhabits lowland aquatic habitats from the Guianas, through eastern Amazonia, to northern Argentina, with a preference for slow-moving rivers and marshes, though it is also encountered away from water. This is one of South America’s largest snakes, after the boas. It preys on a wide variety of aquatic and terrestrial vertebrates and is an adept climber.

RELATED SPECIES

Two additional species are included in genus Hydrodynastes, which was once known as Cyclagras: Hermann’s Watersnake (H. bicinctus), also from northern South America, and the recently described Black False Water Cobra (H. melanogigas) from Tocantins state, central Brazil. This genus appears to be most closely related to the monotypic Amaral’s Groundsnake (Caaeteboia amarali) and the flat-headed snakes (Xenopholis). Hydrodynastes gigas is known locality as Boipevaçu.

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, venomous
DISTRIBUTION	South America: the Guianas to northern Argentina
ELEVATION	0–330 ft (0–100 m) asl
HABITAT	Slow rivers, marshes, and lakes
DIET	Fish, frogs, small mammals, birds, and other reptiles
REPRODUCTION	Oviparous, with clutches of 20–30 eggs
CONSERVATION STATUS	IUCN not yet assessed

The Giant False Water Cobra is a large, smooth-scaled snake with a moderately broad, pointed head and eyes with round pupils. It is mottled brown above with a series of darker-centered and black-edged rhomboid blotches on the back and a broad, black postocular stripe that runs onto the neck. It is pale yellow to grayish brown below. The defensive hood is very impressive.

HYDROPS MARTII
AMAZONIAN SMOOTH-SCALED WATERSNAKE

(WAGLER, 1824)

ADULT LENGTH
2 ft 7 in–3 ft 3 in (0.8–1.0 m)

Also known as the Coral Mudsnake, this brightly colored Amazonian species is recorded from Pará in the mouth of the Brazilian Amazon, to Venezuela, Colombia, Peru, and Ecuador, in the western Amazon. It may be both diurnal and nocturnal and shows a preference for shallow, slow-moving waterways, including oxbow lakes, swamps, and the side channels of larger rivers. Its prey is fairly specialized and consists of synbranchid eels, and possibly also caecilians (legless amphibians), which can be swallowed easily by narrow-mouthed snakes. The reproductive strategy of this species appears to be bimodal, with both egg-laying and live-bearing reported. Nothing is known of the toxicity of its saliva or venom so caution is recommended. This species is named for Carl Friedrich Philipp von Martius (1794–1868), a German botanist who visited Brazil.

RELATED SPECIES

The genus Hydrops contains two other species, the widely distributed Triangle Watersnake (H. triangularis), which has six subspecies across northern and central South America, and the recently described Pantanal Watersnake (H. caesurus), from Paraguay, southern Brazil, and northern Argentina. The most closely related genera are the smooth-scaled glossy pondsnakes (Pseudoeryx), and the South American keeled watersnakes (Helicops), which have keeled scales.

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous
DISTRIBUTION	South America: Amazonian Brazil, Venezuela, Colombia, Ecuador, and Peru
ELEVATION	0–820 ft (0–250 m) asl
HABITAT	Slow and shallow rivers, marshes, and lakes
DIET	Freshwater eels and possibly caecilians
REPRODUCTION	Oviparous or viviparous, with clutches or litters of up to 7
CONSERVATION STATUS	IUCN Least Concern

The Amazonian Smooth-scaled Watersnake is a small snake with a narrow head and small eyes. It is stunningly patterned, with white-edged black bands, or rings, separated by red interspaces, these becoming pale yellow on the venter. The head bears a black-edged white band across the snout, and a white and black collar.

HYPSIRHYNCHUS FEROX
HISPANIOLAN CAT-EYED SNAKE

GÜNTHER, 1858

ADULT LENGTH
271/2–311/2 in (700–800 mm)

The Hispaniolan Cat-eyed Snake occurs in both Haiti and the Dominican Republic, and on Île de la Gonâve (Dominican Republic) and Isla Saona (Haiti). It is a common snake of arid lowland and submontane habitats such as mesic woodland and xeric cactus scrub, where it may be either terrestrial or arboreal. Despite its vertically elliptical, catlike pupils, which suggest nocturnal activity, this snake is often seen during the height of the day. It is an active forager or ambush predator of both terrestrial and arboreal lizards. Juveniles show a preference for anoles. Larger, more terrestrial lizards such as ameivas, galliwasps, and curlytail lizards feature more in the adults’ diet. Females are oviparous.

RELATED SPECIES

Three subspecies are recognized, from the mainland (Hypsirhynchus ferox ferox), Île de la Gonâve (H. f. exedrus), and Isla Saona (H. f. paracrousis). This species’ closest relative is the Tiburon Cat-eyed snake (H. scalaris), a former Haitian subspecies. The genus Hypsirhynchus contains between two and eight species, because some authors place the Hispaniolan and Jamaican species into different genera (Antillophis, Ocyophis, and Schwartzophis). It is feared the Jamaican Racer (H. ater) and the La Vega Racer (H. melanichnus), from Hispaniola, may be extinct.

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Nonvenomous
DISTRIBUTION	West Indies: Hispaniola (Haiti and Dominican Republic)
ELEVATION	0–5,580 ft (0–1,700 m) asl
HABITAT	Dry coastal forest and lowland cactus scrub
DIET	Lizards
REPRODUCTION	Oviparous, with clutches of 3–15 eggs
CONSERVATION STATUS	IUCN not yet assessed

The Hispaniolan Cat-eyed Snake is a small snake with smooth scales, a long tail, a narrow, pointed head, a slightly upturned snout, and small eyes with vertically elliptical pupils. Specimens are dorsally brown or gray, usually with a narrow, dark, viper-like vertebral zigzag pattern. The shape and patterning of this species resembles that of the unrelated bark snakes (Hemirhagerrhis) of Africa.

IALTRIS DORSALIS
HISPANIOLAN FANGED RACER

(GÜNTHER, 1858)

ADULT LENGTH
3 ft–3 ft 3 in (0.9–1.0 m)

The Hispaniolan Fanged Racer is a diurnally active, terrestrial predator of frogs, lizards, and small mammals. It occurs throughout mainland Hispaniola, and on the Haitian islands of Île-à-Vache, Île de la Gonâve, and Île de la Tortue. It frequents dry lowland habitats such as mesic woodland, especially woodland on limestone karst outcrops, but is also found in coffee plantations. Although a rear-fanged venomous species, the Hispaniolan Fanged Racer is not believed to be harmful to humans, and specimens kept in captivity have not attempted to bite. There are no dangerous snakes on Hispaniola or its satellite islands, but caution is advised when handling any large specimens. Females are oviparous.

RELATED SPECIES

There are three other species in the genus Ialtris, all from Hispaniola. The Barreras Fanged Racer (I. agyrtes) occurs in southwestern Dominican Republic, the Haitian Fanged Racer (I. haetianus) occurs in both Haiti and the Dominican Republic, and Parish’s Fanged Racer (I. parishi) is endemic to Île de la Tortue. Some authors place the Haitian Fanged Racer in genus Darlingtonia. Ialtris (and Darlingtonia) are closest to the Hispaniolan and Jamaica racers of genus Hypsirhynchus (shown here).

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous
DISTRIBUTION	West Indies: Hispaniola (Haiti and Dominican Republic)
ELEVATION	0–3,280 ft (0–1,000 m) asl
HABITAT	Dry coastal forest, especially on limestone karst; also coffee plantations
DIET	Frogs, lizards, and small mammals
REPRODUCTION	Oviparous, with clutches of up to 12 eggs
CONSERVATION STATUS	IUCN not yet assessed

The Hispaniolan Fanged Racer is a smooth-scaled snake with a long tail, a moderately broad head with a pointed snout, and small eyes with round pupils. It is usually gray in color, with darker gray flecking on the dorsum of the body, a dark gray nape band, a fine dark gray “W” on the back of the head with the bars forming the postocular stripes, and a fine vertebral stripe. The undersides are brown or gray.

LYGOPHIS LINEATUS
NORTHERN LINED GROUNDSNAKE

(LINNAEUS, 1758)

ADULT LENGTH
133/4–193/4 in, rarely 233/4 in (350–500 mm, rarely 600 mm)

The genus Lygophis contains eight species, with the Northern Lined Groundsnake being the northernmost, occurring from Panama, through Colombia, Venezuela and the Guianas, to Brazil and the mouth of the Amazon. The Northern Lined Groundsnake is a diurnal and terrestrial species that occupies a variety of habitats across its range, from seasonally flooded savanna to dry deciduous woodland, and from wetlands and moist gallery forest to dry thorn scrub. It preys primarily, if not exclusively, on amphibians, mostly frogs. This is a nonvenomous species of no danger to humans. It is generally inoffensive and does not bite. Females produce clutches of five to seven eggs.

RELATED SPECIES

The other species of Lygophis are found through southeastern and central Brazil, Bolivia, Paraguay, Uruguay, and Argentina. The Southern Lined Groundsnake (L. meridionalis) from southeastern Brazil, Bolivia, Paraguay, and Argentina is a former subspecies. Until recently, Lygophis was synonymized within Liophis, itself now a synonym of Erythrolamprus (shown here). It is now considered the sister taxon to a clade comprising Erythrolamprus and Xenodon (shown here).

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Nonvenomous
DISTRIBUTION	Central and South America: Panama, Colombia, Venezuela, the Guianas, and northern Brazil
ELEVATION	0–2,950 ft (0–900 m) asl
HABITAT	Savanna, wetlands, gallery forest, dry deciduous forest, and thorn scrub
DIET	Frogs
REPRODUCTION	Oviparous, with clutches of 5–7 eggs
CONSERVATION STATUS	IUCN not yet assessed

The Northern Lined Groundsnake is a smooth-scaled snake with a long tail, a narrow, pointed head, and moderately large eyes with round pupils. It is light brown above and white to gray below, with three broad, dark brown stripes that begin as a middorsal stripe and two lateral stripes on the head and continue longitudinally down the body. The lateral stripes may become less evident posteriorly.

MAGLIOPHIS STAHLI
PUERTO RICAN RACERLET

(STEJNEGER, 1904)

ADULT LENGTH
53/4–193/4 in (400–500 mm)

The Puerto Rican Racerlet inhabits the majority of Puerto Rico, only being absent from the southern coastal region where a different species occurs. It is generally a secretive, diurnal inhabitant of leaf litter and piles of dead vegetation. It may be found in wet habitats such as rainforest or coastal forest, or in dry woodland, cactus thicket, and also in open pasture. Being relatively small and easily overlooked it can also adapt to living in man-made monocultures such as coconut groves and plantations, and it may inhabit gardens. It is a harmless snake that preys on frogs and small lizards such as anoles or geckos, and it also eats tadpoles and frogs’ eggs when they are available. Females are oviparous, laying up to 18 eggs. Agustín Stahl (1842–1917) was a Puerto Rican medical doctor and naturalist.

RELATED SPECIES

The Puerto Rican Racerlet was previously a subspecies of the Virgin Island Racerlet (Magliophis exiguus). It shares Puerto Rico with another sub-species (M. e. subspadix), which inhabits the south, while the nominate sub-species occurs on the British and US Virgin Islands. The genus Magliophis is closely related to the Greater Antillean racers i.e. Cubophis (shown here), Borikenophis (shown here), Haitiophis, Caraiba (shown here), and Alsophis (shown here).

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Nonvenomous
DISTRIBUTION	West Indies: Puerto Rico
ELEVATION	0–795 ft (0–243 m) asl
HABITAT	Rainforest, coastal forest, dry woods, cactus thicket, open pasture, coconut groves, and gardens
DIET	Frogs, their eggs, tadpoles, and lizards
REPRODUCTION	Oviparous, with clutches of 6–18 eggs
CONSERVATION STATUS	IUCN Least Concern

The Puerto Rican Racerlet is a small, smooth-scaled species with a narrow, slightly pointed head, moderately large eyes with round pupils and a relatively long tail. It is dark gray-brown on the flanks, chestnut brown on the dorsum, separated by a black stripe, which begins on the snout and runs through the eye. The lips are off-white to light gray and the undersides may be yellow-tan, greenish-tan, or orange-brown with brown speckling and a large spot on the outer ventral scales.

MANOLEPIS PUTNAMI
MEXICAN THIN-SCALED SNAKE

(JAN, 1863)

ADULT LENGTH
Male
153/4–221/2 in (400–570 mm)

Female
193/4–281/4 in (500–720 mm)

Also known as the Ridgehead Snake, the Mexican Thin-scaled Snake is distributed along the Pacific coast of Mexico from Nayarit to Chiapas. It inhabits tropical deciduous and semi-deciduous woodland and pine–oak forest and is a diurnal predator of terrestrial lizards such as whiptails and spiny lizards, which are killed by constriction. The Mexican Thin-scaled Snake is reported to be most active in the wet season and is also unusual in that it exhibits a degree of sexual dimorphism, females being much larger, and dichromatism, with females generally being much darker than males, though with a pale center to the distinctive vertebral stripe. In common with most xenodontines, this species is oviparous. Frederic Ward Putnam (1839–1915) was an American anthropologist, zoologist, and museum curator.

RELATED SPECIES

The monotypic genus Manolepis is most closely related to the South American smooth watersnakes (Hydrops), South American keeled watersnakes (Helicops), and glossy pondsnakes (Pseudoeryx).

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Nonvenomous, constrictor
DISTRIBUTION	North America: western Mexico
ELEVATION	0–6,230 ft (0–1,900 m) asl
HABITAT	Tropical deciduous woodland, semi-deciduous woodland, and pine-oak forest
DIET	Lizards
REPRODUCTION	Oviparous, with clutches of up to 10 eggs
CONSERVATION STATUS	IUCN Least Concern

The Mexican Thin-scaled Snake is a small snake, with smooth to slightly carinate scales, a slender body, a relatively long tail, and a narrow, pointed, angular head with large eyes and round pupils. It is brown to yellow dorsally, with a broad, dark vertebral stripe, which is light-centered in females but fully dark in males. The head is light or dark gray, flecked with black and with black marks on the dorsum and under the eyes. The undersides of the head and body are dark in females, and much lighter in males.

MUSSURANA BICOLOR
BICOLORED MUSSURANA

(PERACCA, 1904)

ADULT LENGTH
Male
193/4–251/2 in (500–650 mm)

Female
193/4–291/2 in, rarely 39 in (500–750 mm, rarely 990 mm)

The Bicolored Mussurana is the smallest species of mussurana in South America, and the only species that fails to achieve 3 ft 3 in (1 m) in total length. Terrestrial and nocturnal, it occurs in central and southern Brazil, Paraguay, and northern Argentina, where it inhabits dry Chaco forest and seasonally flooded Pantanal wetlands. It is also present in the transition zone to the wet Atlantic coastal forests, but is nowhere a commonly encountered species. It is therefore relatively little studied. It preys on snakes, including South American keeled watersnakes (Helicops), but is also a generalist vertebrate predator that takes frogs, lizards, and small mammals. Prey is dispatched with a combination of venom and constriction. This species is generally inoffensive and rarely bites, but as with most rear-fanged species care is advised.

RELATED SPECIES

The genus Mussurana contains two other species, the Montane Mussurana (M. montana) and Quim’s Mussurana (M. quimi), named in honor of the herpetologist Joaquim (Quim) Cavalheiro. Both species are found in southeastern Brazil. This genus is closely related to the other mussurana genera, Boiruna (shown here), Clelia (shown here), and Paraphimophis (shown here), and the Lizard Egg-eating Snake (Drepanoides).

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous; also constrictor
DISTRIBUTION	South America: central and southern Brazil, Paraguay, and northern Argentina
ELEVATION	410–1,530 ft (125–465 m) asl
HABITAT	Chaco dry forest and seasonally flooded Pantanal wetlands, to the transition with wet coastal forest
DIET	Snakes, lizards, small mammals, and frogs
REPRODUCTION	Oviparous, clutch size uncertain, probably 7–10 eggs
CONSERVATION STATUS	IUCN Least Concern

The Bicolored Mussurana is a small snake, with smooth, glossy scales, a rounded, flattened head, and moderately small eyes with round pupils. It exhibits an ontogenetic color change, from a juvenile and immature adult with red flanks, a dark red to brown dorsum, and a pale venter, to an adult with a totally black dorsum, contrastingly white lips, and pale undersides and sometimes white bands on the dorsum.

OXYRHOPUS FORMOSUS
BEAUTIFUL CALICO SNAKE

(WIED-NEUWIED, 1820)

ADULT LENGTH
311/2–353/4 in (800–910 mm)

Also known as the Yellow-headed Calico Snake, the Beautiful Calico Snake is found across northern South America from Colombia to Peru and Brazil. It usually inhabits pristine rainforest habitats but is also found in secondary growth areas and cultivated plots, and it may be nocturnal or crepuscular, and terrestrial to semi-arboreal in habit. The only prey documented for this species was a microteiid lizard, but with the knowledge that other calico snakes also prey on frogs, snakes, and rodents it is reasonable to assume that the diet of the Beautiful Calico Snake is more catholic than just lizards. The prey is restrained in the snake’s constricting coils while the slow-acting venom takes effect. Calico snakes are usual inoffensive and not considered dangerous to humans.

RELATED SPECIES

Generally called calico snakes, the 14 brightly colored species of the genus Oxyrhopus are distributed from Mexico to Argentina. Several are false coralsnakes, mimicking highly venomous true coralsnakes (Micrurus) within their ranges. The calico snakes form a sister clade to a group comprising the mussuranas (Boiruna; Clelia; Mussurana; and Paraphimophis) and their kin. Oxyrhopus formosus is most closely related to the Brazilian Calico Snake (O. trigeminus), a distinctive false coralsnake.

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous
DISTRIBUTION	South America: Colombia, Venezuela, northern Brazil, Ecuador, Peru, and Bolivia
ELEVATION	655–3,280 ft (200–1,000 m) asl
HABITAT	Primary and secondary rainforest, and cultivated gardens
DIET	Lizards, and possibly other vertebrates
REPRODUCTION	Oviparous, with clutches of up to 17 eggs
CONSERVATION STATUS	IUCN not yet assessed

The Beautiful Calico Snake is a slender snake, with smooth scales, a slightly pointed head, small eyes with round pupils, and a long tail. It may be banded dark gray and red like the Broad-banded Calico Snake (O. petolarius) or it may be orange to red throughout, with each scale tipped with black, a black cap over the posterior of the head being present or absent, and a yellow snout and lips. The iris is often bright red, contrasting strongly with the head markings.

OXYRHOPUS PETOLARIUS
BROAD-BANDED CALICO SNAKE

(LINNAEUS, 1758)

ADULT LENGTH
Male
361/4–441/2 in (920–1,130 mm)

Female
381/2–471/4 in (980–1,200 mm)

The Broad-banded Calico Snake is the most widely distributed member of its genus, being found from Mexico to Argentina, in lowland and low montane wet forests and savannas. It is a nocturnal species that spends most of its time on the ground, especially after heavy rainfall, but also climbs well and is encountered during the day. It preys on small lizards, with frogs and rodents also featuring in its diet. Birds and snakes are also sometimes taken, including rustyhead snakes (Amastridium). Prey is killed with a combination of weak venom and constriction. The Broad-banded Calico Snake is another false coralsnake that may gain a degree of protection by mimicking more dangerous true coralsnakes (Micrurus). Inoffensive and disinclined to bite, it is not believed dangerous to humans.

RELATED SPECIES

Three subspecies are recognized, the nominate form (Oxyrhopus petolarius petolarius) occurring across northern South America from Colombia to Trinidad and Tobago, with an Amazonian subspecies (O. p. digitalis) throughout the Amazon Basin to Argentina, and a northern form (O. p. sebae) in Mexico and Central America.

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous; also constrictor
DISTRIBUTION	North, Central, and South America: southeastern Mexico to Panama, Colombia to the Guianas and Trinidad, and south to Argentina
ELEVATION	0–9,020 ft (0–2,750 m) asl
HABITAT	Lowland and low montane wet forests and savannas
DIET	Lizards, small mammals, frogs, snakes, and birds
REPRODUCTION	Oviparous, with clutches of 5–15 eggs
CONSERVATION STATUS	IUCN not yet assessed

The Broad-banded Calico Snake is a medium-sized snake with a slender body, smooth scales, a long tail, an elongate head that is slightly broader than the neck, and small eyes with round pupils. It is usually light or dark gray with a distinctive series of red or orange bands over the back, these bands often being lighter, even white, anteriorly, and beginning with a broad band over the posterior of the head behind a black-capped snout. The undersides are pale gray.

PARAPHIMOPHIS RUSTICUS
BROWN MUSSURANA

(COPE, 1878)

ADULT LENGTH
311/2–351/2 in, rarely 4 ft 3 in (800–900 mm, rarely 1.3 m)

The Brown Mussurana was formerly included in the genus Clelia, the mussuranas or snake-eaters. A southern species, from southern Brazil, Uruguay, and northern and central Argentina, it is not a large snake, rarely exceeding 3 ft 3 in (1 m) in total length. It is terrestrial and nocturnal, but unlike many other mussurana species it inhabits semiarid to wet open habitats such as grasslands, wetlands, and sand dune areas, and is also found on the outskirts of towns. This is an inoffensive snake that does not bite when handled. Its prey consists of small snakes, such as small swamp snakes (Erythrolamprus reginae), as well as lizards, small birds, and rodents, which are killed by constriction and venom injected via the rear fangs. Females are oviparous, producing clutches of seven to eight eggs between February and March.

RELATED SPECIES

The genus Paraphimophis was created to include this single species, which has also been placed in Clelia (shown here), Oxyrhopus (shown here), and Pseudoboa (shown here). Within the mussurana clade, its closest relatives are the pampas snakes (Phimophis).

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous; also constrictor
DISTRIBUTION	South America: southern Brazil, Uruguay, and Argentina
ELEVATION	No elevations available
HABITAT	Open habitats, grassland, wetlands, sandy areas with coarse grass, dunes, suburban areas
DIET	Snakes, lizards, birds, and small mammals
REPRODUCTION	Oviparous, with clutches of up 7–8 eggs
CONSERVATION STATUS	IUCN not yet assessed

The Brown Mussurana is a small, muscular snake with smooth, glossy scales, a narrow, pointed head, large eyes, and round pupils. It is generally uniform brown, though more yellow-brown on the lower flanks and venter than on the dorsum.

PHALOTRIS LEMNISCATUS
ARGENTINE BLACK-HEADED SNAKE

(DUMÉRIL, BIBRON & DUMÉRIL, 1854)

ADULT LENGTH
113/4–271/2 ft (300–700 mm)

Sometimes called Duméril’s Diadem Snake, the Argentine Black-headed Snake is a terrestrial or semi-fossorial species found in meadows, on rocky hillsides, and on sandy banks in southeastern Brazil, Bolivia, Paraguay, Uruguay, and northern Argentina. It is nocturnal and secretive, often sheltering in mammal burrows underground during the day. Due to its small mouth gape, its prey is usually elongate in shape. It takes amphisbaenians (worm-lizards), slender lizards, small snakes, earthworms, slugs, and some insects. Although a small snake, with a small mouth and rear fangs, it possesses remarkably toxic venom and one herpetologist, who was bitten between the fingers, suffered an extremely serious envenoming with renal failure and bleeding, and almost died. Therefore this species, and all its generally inoffensive relatives, must be treated with extreme caution.

RELATED SPECIES

Four subspecies are recognized, the nominate form (Phalotris lemniscatus lemniscatus) from northeastern Argentina, and three subspecies in the rest of the range (P. l. trilineatus, P. l. divittatus, and P. l. iheringi). Some authors treat these taxa as full species. Phalotris also contains 15 other species, mostly distributed though southern South America. These snakes were previously contained within the genus Elapomorphus (shown here), which is still recognized for two species.

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, venomous: possibly hemorrhagins
DISTRIBUTION	South America: southeastern Brazil, Bolivia, Paraguay, Uruguay, and northern Argentina
ELEVATION	0–1,640 ft (0–500 m) asl
HABITAT	Meadows and rocky hillsides, sandbanks, and mammal burrows
DIET	Amphisbaenians, lizards, snakes, slugs, insects, and earthworms
REPRODUCTION	Oviparous, with clutches of 1–8 eggs
CONSERVATION STATUS	IUCN Least Concern

The Argentine Black-headed Snake is a very slender, smooth-scaled snake with a short tail, a narrow head that is indistinct from the neck, small eyes, and round pupils. It is brown above and yellowish below, with a pair of orange paravertebral stripes along the back and a yellow collar around the neck, posterior to the black head.

PHILODRYAS BARONI
BARÓN’S BUSH RACER

BERG, 1895

ADULT LENGTH
3 ft 3 in–5 ft, occasionally 6 ft (1.0–1.5 m, occasionally 1.8 m)

Probably the most instantly recognizable member of its genus, Barón’s Bush Racer is a South American species from Bolivia, northwestern Paraguay, and northern Argentina. It is an open country snake, found in grasslands, on rocky hillsides, and even on salt pans. Although primarily terrestrial, it easily adopts an arboreal lifestyle when required. It feeds on frogs, lizards, and birds, and may also take small mammals. As with all members of its genus, Barón’s Bush Racer is irascible, biting at any opportunity and chewing vigorously to bring its rear fangs into play. Given the proven toxicity of its congener, Lichtenstein’s Green Racer (Philodryas olfersii), snakebites from this species are to be avoided, especially as this is a popular species in captivity with owners often unaware of its potential. Manuel Barón Morlat collected the holotype.

RELATED SPECIES

The genus Philodryas contains 23 species. Philodryas baroni can be distinguished from its two most similar, sympatric species, the Patagonian Bush Racer (P. patagoniensis) and the Argentine Bush Racer (P. trilineata), by its distinctive fleshy snout protuberance. Barón’s Bush Racer is also closely related to Natterer’s Bush Racer (P. nattereri) from eastern and southern Brazil, which also lacks a snout protuberance.

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, venomous: possibly hemorrhagins
DISTRIBUTION	South America: Bolivia, Paraguay, and northern Argentina
ELEVATION	490–985 ft (150–300 m) asl
HABITAT	Open grassland, rocky hillsides, and salt pans
DIET	Frogs, lizards, and birds; possibly small mammals
REPRODUCTION	Oviparous, with clutches of 4–11 eggs
CONSERVATION STATUS	IUCN not yet assessed

Barón’s Bush Racer is a large, smooth-scaled snake with a moderately long tail and a narrow head that terminates in a characteristically upturned fleshy snout protuberance. Its eyes are large with round pupils. Two color morphotypes are known, an all-green morphotype that is paler green below and on the lips, and a brown morphotype, which has a dark brown vertebral stripe, a paler brown lateral stripe that begins on the snout, and white lips and undersides that may have a pinkish tinge.

PHILODRYAS CHAMISSONIS
CHILEAN LONG-TAILED BUSH RACER

(WIEGMANN, 1835)

ADULT LENGTH
3 ft 3 in–5 ft (1.0–1.5 m)

The Chilean Long-tailed Bush Racer is endemic to Chile, being found only in the area between the Atacama Desert and Bío-Bío. It is an inhabitant of relatively dry habitats, including rocky hillsides, open grasslands, and dry stone walls around cultivated areas. It preys on lizards, frogs, nestling birds, and small mammals, including young rabbits. Prey is killed with a combination of venom and constriction. This species can be truculent and may bite freely if handled. Other members of the genus Philodryas have caused painful and potentially serious snakebites, and, similarly, extensive edema has been observed in cases of severe envenoming following bites by this species. Recovery may take four to six days, so caution is advised with all Chilean rear-fanged snakes.

RELATED SPECIES

Chile is home to only six snake species, four of which are in the genus Philodryas, but were previously included in Dromicus: P. chamissonis, the Elegant Bush Racer (P. elegans), the Peruvian Bush Racer (P. tachymenoides), and Simons’ Bush Racer (P. simonsii). There are also two species of scrub snakes (Tachymenis). Chile is the only mainland American country to lack any front-fanged pitvipers or coralsnakes, but its rear-fanged species warrant caution.

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, highly venomous: contains an anticoagulant and proteolytic; also a constrictor
DISTRIBUTION	South America: central Chile
ELEVATION	0–6,230 ft (0–1,900 m) asl
HABITAT	Dry hillsides, grassland, agricultural habitats, and dry stone walls
DIET	Small mammals, frogs, birds, and lizards
REPRODUCTION	Oviparous, with clutches of 6–8 eggs
CONSERVATION STATUS	IUCN Least Concern

The Chilean Long-tailed Bush Racer is a moderately stout snake with smooth scales, a long tail, and a head slightly broader than the neck, with large eyes and round pupils. It is generally brown in color with a series of four yellow longitudinal stripes, edged with black, white lips, and an off-white underbelly.

PHILODRYAS OLFERSII
LICHTENSTEIN’S GREEN RACER

(LICHTENSTEIN, 1823)

ADULT LENGTH
291/2–371/2 in, rarely 3 ft 7 in (750–950 mm, rarely 1.1 m)

Usually called Lichtenstein’s Green Racer, this species should really be called Von Olfers’ Green Racer, because the German zoologist Martin Lichtenstein (1780–1857) named it in honor of his compatriot, Ignaz Franz Werner Maria von Olfers (1793–1871). Lichtenstein’s Green Racer is widely distributed through most of northern and central South America, east of the Andes. It is diurnal, terrestrial and semi-arboreal, and inhabits degraded forest, grassland, scrubland, and cultivated areas. It feeds on frogs, lizards, birds, other snakes, and rodents, and possesses a particularly toxic venom. Numerous snakebites are on record, with painful swelling and discoloration common, and there is also the possible fatality of a small child. This species, and its conspecifics, should therefore be treated with respect and caution.

RELATED SPECIES

Three subspecies are recognized, the nominate eastern subspecies (Philodryas olfersii olfersii), a northern subspecies (P. o. herbeus), and a western and southern subspecies (P. o. latirostris). The species most similar in appearance to P. olfersii is the Common Green Racer (P. viridissima), with which it occurs in sympatry, but the two can be separated by their ventral scale counts, which come to fewer than 205 in P. olfersii, and over 205 in P. viridissima.

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, venomous: contains hemorrhagins, procoagulants, myotoxins, and postsynaptic neurotoxins
DISTRIBUTION	South America: Colombia, Venezuela, the Guianas, Brazil, Peru, Bolivia, Paraguay, Uruguay, and northern Argentina
ELEVATION	0–1,640 ft (0–500 m) asl
HABITAT	Savanna, degraded forest, scrubland, and cultivated areas
DIET	Frogs, lizards, birds, snakes, and small mammals
REPRODUCTION	Oviparous, with clutches of 7–8 eggs
CONSERVATION STATUS	IUCN not yet assessed

Lichtenstein’s Green Racer is a relatively slender snake with smooth scales, a long tail, a head slightly wider than the neck, and large eyes with round pupils. It is grass- or yellow-green above, often with blue on the throat, and paler green below. A fine black line runs through the eye above the pale green lips.

PHIMOPHIS GUIANENSIS
GUIANAN SHOVEL-NOSED PAMPAS SNAKE

(TROSCHEL, 1848)

ADULT LENGTH
193/4–251/2 in (500–650 mm)

The Guianan Shovel-nosed Pampas Snake is a distinctive but rarely encountered species. Found in Panama and northern South America, it is an inhabitant of relatively arid habitats, from savanna to thornbush and dry deciduous forest. In the Guianas it is largely confined to the narrow coastal savanna strip, but it is more widely distributed in Venezuela, where it occurs in the Llanos region, and in the savannas and gallery forest to the north and south of the Orinoco. It is nocturnal, and both terrestrial and semi-fossorial in habit. Prey consists primarily of lizards, and sometimes frogs. When handled these small snakes are reluctant to bite, but will void the contents of their cloacal glands or defecate defensively. Although technically rear-fanged and venomous, they are not generally considered dangerous to humans.

RELATED SPECIES

Two other species are recognized within the genus Phimophis: the Eastern Shovel-nosed Pampas Snake (P. guerini), from the Guianas, eastern and southern Brazil, Paraguay, and northern Argentina, and the Striped Shovel-nosed Pampas Snake (P. vittatus) from southern Bolivia, Paraguay, and northern Argentina. The genus Phimophis, and its close relative, the Brown Mussurana (Paraphimophis rusticus), form the sister clade to all the other mussuranas (Boiruna; Clelia; Mussurana; and Paraphimophis, and the scarlet snakes (Pseudoboa).

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous; also constrictor
DISTRIBUTION	Central and South America: Panama, Colombia, Venezuela, Guyana, Suriname, and French Guiana; possibly northern Brazil
ELEVATION	0–2,950 ft (0–900 m) asl
HABITAT	Coastal savanna, riverine grasslands, dry woodland, thornbush woodland, gallery forest, and deciduous forest
DIET	Lizards and frogs
REPRODUCTION	Oviparous, with clutches of 4–7 eggs
CONSERVATION STATUS	IUCN not yet assessed

The Guianan Shovel-nosed Pampas Snake is a smooth-scaled snake with a relatively short tail, a broad head that terminates in an upturned shovel-snout, and moderately large eyes with round pupils. Dorsal coloration is fairly variable, being yellow or white with brown, yellow, or red mottling on every scale, while the venter and lower flanks are immaculate white or pale yellow. The dorsum of the head and neck are distinctively dark.

PSEUDALSOPHIS STEINDACHNERI
STRIPED GALAPAGOS RACER

(VAN DENBURGH, 1912)

ADULT LENGTH
Male
193/4–24 in (500–610 mm)

Female
193/4–211/4 in (500–540 mm)

The Striped Galapagos Racer is found on the central Galapagos Islands of Baltra, Rábida, Santa Cruz, and Santiago. It inhabits coastal and inland arid areas and hunts geckos, lava lizards, rodents, nestling birds, and possibly large insects. Vertebrate prey is killed by constriction. Even given the popularity of the Galapagos Islands, its snakes are poorly studied, herpetologists possibly concentrating more on the famous tortoises and iguanas. Yet before Charles Darwin famously visited the Galapagos in 1835, the presence of the racers was noted by the English buccaneer and naturalist William Dampier (1651–1715). Although the racers are believed to be oviparous, there are no data for clutch sizes available. Franz Steindachner (1834–1919) was an Austrian zoologist.

RELATED SPECIES

The genus Pseudalsophis contains seven species. Only the Western Elegant Racer (P. elegans) occurs on the mainland, in Ecuador, Peru, and northern Chile. Pseudalsophis steindachneri occurs in sympatry with the Central Galapagos Racer (P. dorsalis). The Eastern Galapagos Racer (P. biserialis) inhabits San Cristóbal, Floreana, and neighboring islands, the Española Racer (P. hoodensis) occurs on Española, and the Western Galapagos Racer (P. occidentalis) and Banded Galapagos Racer (P. slevini) occur on Isabela, Fernandina, and neighboring islands. Several of these species contain island endemic subspecies.

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Nonvenomous, constrictor
DISTRIBUTION	Pacific Islands: Galapagos Islands (Ecuador)
ELEVATION	0–2,620 ft (0–800 m) asl
HABITAT	Coastal and arid habitats
DIET	Lizards, small mammals, birds, and insects
REPRODUCTION	Oviparous, clutch size unknown
CONSERVATION STATUS	IUCN not yet assessed

The Striped Galapagos Racer is a small, smooth-scaled snake with a long tail, a narrow, elongate head, large eyes, and round pupils. It is dorsally dark brown with a pair of dorsolateral yellow to buff stripes, which begin behind the eyes, and a white throat, lips, and underbelly. The Española Racer (Pseudalsophis hoodensis) is similarly patterned.

PSEUDOBOA MARTINSI
BLACK-STRIPED SCARLET SNAKE

ZAHER, OLIVEIRA & FRANCO, 2008

ADULT LENGTH
3 ft 3 in–3 ft 7 in (1.0–1.09 m)

Snakes in the genus Pseudoboa are often called “false boas,” a literal translation of the generic name, although they do not resemble boas. Scarlet snake or false mussurana are more apt. The Black-striped Scarlet Snake is a stunning species, only described in 2008, from the northern Brazilian states of Pará, Amazonas, Roraima, and Rondônia. It may yet be discovered in neighboring countries. It inhabits primary rainforest and is associated with watercourses. One specimen contained the remnants of a snake, the common prey of mussuranas. Nothing else is known of its natural history, other than it occurs in leaf litter or under logs, and is oviparous. It does not bite or defend itself in any way. The species is named for the Brazilian herpetologist Marcio Martins from Universidade do São Paulo.

RELATED SPECIES

The genus Pseudoboa contains five other species. The Northern Scarlet Snake (P. neuwiedii) and the Amazonian Scarlet Snake (P. coronata), bright red species with black heads, occur in northern South America. The Serrana False Mussurana (P. serrana), of southeastern Brazil, and Haas’ False Mussurana (P. haasi), of southern Brazil and Argentina, are red with black stripes and black heads. The Black False Mussurana (P. nigra), of eastern Brazil and Paraguay, is black with white markings. Closely related species include the Black-tailed Mussurana (Boiruna maculata) and the Brazilian Birdsnake (Rhachidelus brazili).

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous
DISTRIBUTION	South America: northern Brazil
ELEVATION	No elevation available
HABITAT	Primary rainforest and streamsides
DIET	Snakes
REPRODUCTION	Oviparous, clutch size unknown
CONSERVATION STATUS	IUCN not yet assessed

The Black-striped Scarlet Snake has smooth, glossy scales, a long tail, and a head only slightly distinct from the neck, with small eyes and round pupils. It is bright red above with a black snout, a broad red posterior head and nape band, and a wide black vertebral stripe that continues the length of the body and tail. The undersides are immaculate white. Juveniles are similarly patterned, but with a broad white collar, a common feature of juveniles of all species in the genus.

PSEUDOERYX PLICATILIS
SOUTH AMERICAN GLOSSY PONDSNAKE

(LINNAEUS, 1758)

ADULT LENGTH
3 ft 3 in–3 ft 7 in, occasionally 5 ft (1.0–1.1 m, occasionally 1.5 m)

The South American Glossy Pondsnake is found through northern and central South America, east of the Andes, from Colombia to northern Argentina. This species is nocturnal or diurnal and inhabits slow-moving rivers, oxbow lakes, ponds, canals, and marshes where the water flow is gentle. It feeds almost exclusively on fish, including eels, but also takes frog tadpoles. It is generally believed to be oviparous, with large clutches of eggs, but some authors suggest that certain populations may be viviparous. The usual defense of the South American Glossy Pondsnake is to hide its head under its coils and flatten its body, and although nonvenomous, it bites easily if handled. This species goes through an ontogenetic color change from light, bright juvenile to drab, dark adult livery.

RELATED SPECIES

There are two subspecies recognized, the nominate form (Pseudoeryx plicatilis plicatilis), which occupies the bulk of the range, and a southwestern form (P. p. mimeticus), from Amazonian Bolivia and neighboring Brazil. Another species has recently been described, the Lake Maracaibo Pondsnake (P. relictualis), from northwestern Venezuela. Pseudoeryx is most closely related to the South American smooth watersnakes (Hydrops) and keeled watersnakes (Helicops). In habit it appears similar to the Rainbow Snake and Mudsnake (Farancia) of North America.

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Nonvenomous
DISTRIBUTION	South America: Colombia, Venezuela, the Guianas, Brazil, Peru, Bolivia, Paraguay, and northern Argentina
ELEVATION	0–1,350 ft (0–410 m) asl
HABITAT	Slow-moving watercourses, oxbow lakes, marshes, canals, and ponds
DIET	Fish (including eels), and tadpoles
REPRODUCTION	Oviparous, clutch size up to 49 eggs; possibly also viviparous
CONSERVATION STATUS	IUCN Least Concern

The South American Glossy Pondsnake is a fairly large snake with glossy, smooth scales, a short tail, and a short head with large, slightly forward-facing eyes and round pupils. It is medium to dark brown above with a pair of dark brown lateral stripes that run off the head and down the body, broken by a pale spot on the neck, with a pair of yellow-brown stripes above and yellow on the lips below. The undersides are cream, or red in juveniles, with rows of small black spots.

PSOMOPHIS JOBERTI
JOBERT’S GROUNDSNAKE

(SAUVAGE, 1884)

ADULT LENGTH
141/2 in (370 mm)

Jobert’s Groundsnake is a diurnal and terrestrial inhabitant of lowland semiarid Cerrado savanna woodland, campo grasslands, and Caatinga thorn forest and arid scrubland. It is found in eastern Brazil, from Pará to Rio Grande do Norte, and south to Minas Gerais and São Paulo, although its collection localities are scattered over a wide area, some being separated by areas of wet forest, in which it does not occur, so its distribution is unlikely to be continuous. The Ilha de Marajó is one such isolated savanna area. Jobert’s Groundsnake preys on lizards, and is an oviparous species, with a clutch of four eggs documented. The holotype was collected on the Ilha de Marajó, in the mouth of the Amazon, by Clément-Léger-Nicolas Jobert (1840–1910), a French zoologist and botanist who documented the Amerindian use of curare (arrow poison).

RELATED SPECIES

Two additional species are recognized in the genus, the Spirit Groundsnake (Psomophis genimaculatus) from southwestern Brazil, Bolivia, Paraguay, and northern Argentina, and the Wide Groundsnake (P. obtusus) from southern Brazil, Paraguay, Uruguay, and northern Argentina, both of which can be distinguished from P. joberti by a downward-pointing dark patch beyond the last supralabial. The most closely related genera are the Central American road guarders (Conophis and Crisantophis).

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous
DISTRIBUTION	South America: eastern Brazil
ELEVATION	0–410 ft (0–125 m) asl
HABITAT	Cerrado savanna woodland, campo grasslands, and Caatinga thorn forest and scrubland
DIET	Lizards
REPRODUCTION	Oviparous, with clutches of up to 4 eggs
CONSERVATION STATUS	IUCN not yet assessed

Jobert’s Groundsnake is a slender snake with smooth scales, a long tail, and a head slightly wider than the neck, with large eyes and round pupils. It is brown above with a dark brown vertebral stripe the length of the body and tail, and fainter brown lateral stripes. A dark stripe runs from the snout, through the eye, to the angle of the jaw, above the white lips. The undersides are pale brown to cream.

RODRIGUESOPHIS IGLESIASI
IGLESIAS’ LONG-NOSED PAMPAS SNAKE

(GOMES, 1915)

ADULT LENGTH
191/4–193/4 in (490–500 mm)

Iglesias’ Long-nosed Pampas Snake is the most widely distributed member of its genus, occurring in the Brazilian states of Bahia, Minas Gerais, Piauí, and Tocantins. It forms part of the highly specialized psammophilous (sandy habitat) herpetofauna associated with the São Francisco River. This species inhabits arid Caatinga woodland and savanna grasslands, where it exhibits a nocturnal and fossorial lifestyle in the sandy substrate. Its prey comprises equally fossorial microteiid lizards. Fossorial snakes are, by definition, difficult to study in nature. This species is known to be oviparous, but there are no clutch size data available. Miguel Trefaut Urbano Rodrigues is a Portuguese herpetologist, and an expert on the fossorial herpetofauna of the São Francisco River. Francisco Iglesias was a Brazilian zoologist. The holotype was lost in the Instituto Butantan fire of May 2010.

RELATED SPECIES

Two other long-nosed pampas snakes are recognized, the Santo Inacio Long-nosed Pampas Snake (Rodriguesophis chui), and the Ibiraba Long-nosed Pampas Snake (R. scriptorcibatus). The name of the second species, scriptorcibatus, means “the one that eats writers,” which would be incomprehensible without the knowledge that it preys on microteiid lizards (Calyptommatus), which are locally known as “escrivoes” (clerks or writers), due to the tracks they leave in the sand.

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous
DISTRIBUTION	South America: northeastern Brazil
ELEVATION	985–1,970 ft (300–600 m) asl
HABITAT	Caatinga woodland and savanna
DIET	Lizards
REPRODUCTION	Oviparous, with clutches of up to 4 eggs
CONSERVATION STATUS	IUCN not yet assessed

Iglesias’ Long-nosed Pampas Snake is a small, smooth-scaled snake with a short tail, a remarkably long, pointed head, and small eyes with vertically elliptical pupils. It is generally pinkish or orange above and yellow or white below, with a pinkish dorsum to the head, followed by a broad black patch in the nape region.

SAPHENOPHIS BOURSIERI
BOURCIER’S ANDEAN SNAKE

(JAN, 1867)

ADULT LENGTH
191/4–231/4 in (490–590 mm)

Bourcier’s Andean Snake is the most widely distributed species in the genus, but even this species is poorly represented in museum collections. It is found at elevations between 3,280 and 6,200 ft (1,000 and 1,890 m) in the southern Colombian and Ecuadorian Andes, but there are also records from 985 ft (300 m) in the Amazonian lowlands of Ecuador. All five members of genus Saphenophis are poorly known. They occur in humid habitats and are likely diurnal due to the cool temperatures that exist at higher elevations at night, and they are oviparous, though clutch size data are lacking. Nothing is known of their prey preferences. They are rear-fanged and mildly venomous, but unlikely to be dangerous to humans. Jules Bourcier (1797–1873) was the French Consul to Ecuador and a hummingbird collector.

RELATED SPECIES

The five species in genus Saphenophis are found at elevations of up to 10,500 ft (3,200 m) in the Ecuadorian and Colombian Andes. Four are only known from their type localities, the Antioquia Snake (S. antioquiensis) at 8,400 ft (2,560 m) in Colombia, Atahuallpa Snake (S. atahuallpae) at 8,200 ft (2,500 m) in Ecuador, Von Sneidern’s Andean Snake (S. sneiderni) from El Tambo, at 5,730 ft (1,745 m), in Colombia, and the Cauca Snake (S. tristriatus), at up to 10,500 ft (3,200 m) in the Cauca Valley, Colombia.

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous
DISTRIBUTION	South America: Andean Colombia and Ecuador
ELEVATION	985 or 3,280–6,200 ft (300 or 1,000–1,890 m) asl
HABITAT	Moist montane habitats
DIET	Prey preferences unknown
REPRODUCTION	Oviparous, clutch size unknown
CONSERVATION STATUS	IUCN not yet assessed

Bourcier’s Andean Snake is a slender snake with smooth scales, a long tail, a head just distinct from the neck, large eyes, and round pupils. It is light brown above, with a pair of darker brown, yellow-edged, longitudinal stripes, although these may be faint on the anterior body. The lips, throat, and underbelly are white or yellow, the former flecked with black, and the latter with scattered black checkerboard markings.

SIPHLOPHIS COMPRESSUS
RED-HEADED LIANA SNAKE

(DAUDIN, 1803)

ADULT LENGTH
3 ft 3 in–4 ft (1.0–1.2 m)

Also known as the Tropical Flatsnake, the Red-headed Liana Snake is a widely distributed species, found from Costa Rica, to Trinidad and Paraguay. It is a highly arboreal, sometimes terrestrial, nocturnal or crepuscular species that inhabits lowland rainforest, tropical evergreen forest, and edge situations, where tropical forests meet savanna. It is believed to feed primarily on lizards, which are killed by a combination of venom and constriction. Large arthropods are reportedly also taken. The Red-headed Liana Snake is oviparous, with clutches of up to six eggs being found in parasol and leaf-cutter ant nests, presumably for protection from oophagous (egg-eating) animals. More than one clutch of eggs may be found in the same ants’ nest. Nothing is known about the effects of the venom on humans.

RELATED SPECIES

Some authors retain the monotypic genus Tripanurgos for this species. From Panama to Bolivia it occurs in sympatry with the Common Liana Snake (Siphlophis cervinus), which is banded black and white on the body, with a vertebral rows of large red spots. The remaining five species in the genus are confined to northwestern, eastern, and southeastern Brazil. The liana snakes form a clade which is the sister clade to the mussuranas (Boiruna; Clelia; Mussurana; and Paraphimophis), and the calico snakes (Oxyrhopus).

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous
DISTRIBUTION	Central and South America: Costa Rica, Panama, Colombia, Venezuela, the Guianas, Trinidad, Brazil, Ecuador, Peru, Bolivia, and Paraguay
ELEVATION	0–625 ft (0–190 m) asl
HABITAT	Lowland rainforest, humid evergreen forest, and edge situations
DIET	Lizards and large insects
REPRODUCTION	Oviparous, with clutches of up to 6 eggs
CONSERVATION STATUS	IUCN Least Concern

The Red-headed Liana Snake is an extremely elongate snake with a slender, laterally compressed body (hence the name compressus), which earns it the alternative name of Tropical Flatsnake. It has smooth scales, a long, prehensile tail, and a moderately broad head with large eyes and vertically elliptical pupils. The body is red to pink with equally spaced black bands, while the head is usually red with an orange or yellowish collar, followed by a broad black dorsal patch. The iris of the eye is also red.

TACHYMENIS CHILENSIS
CHILEAN SHORT-TAILED SCRUB SNAKE

(SCHLEGEL, 1837)

ADULT LENGTH
233/4–271/2 in (600–700 mm)

Also known as the Chilean Slender Snake, the Chilean Short-tailed Scrub Snake is the southernmost snake in Chile, occurring as far south as Puerto Montt and the Chiloé Archipelago. It is also found in the Andes to 6,560 ft (2,000 m) asl, and in Argentina, at similar elevations. Preferred habitats include pastures and meadows, humid forests, and coastal scrub. This species is found in relatively cool areas and is diurnal in activity, despite its vertically elliptical pupils, and live-bearing in reproductive strategy. Its prey consists of frogs, toads, and lizards, which are killed by the snake’s venom. Snakebites to humans have resulted in severe symptoms, including pain and swelling, so Tachymenis should be treated with respect. Chile is the only American mainland country to lack any front-fanged pitvipers or coralsnakes.

RELATED SPECIES

Chile is home to only two genera of snakes, Tachymenis (two species) and Philodryas (four species, shown here). Two subspecies of T. chilensis are recognized, a northern form (T. c. coronellina) and the nominate, southern form (T. c. chilensis). The second species of Tachymenis occurring in Chile is the Peruvian Scrub Snake (T. peruviana), which just enters northern Chile. Four other species inhabit Peru and Bolivia. Tachymenis is related to the mock vipers (Thamnodynastes) and Argentine Mock Lancehead (Pseudotomodon trigonatus).

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous: proteolytic and hemolytic; potentially dangerous
DISTRIBUTION	South America: Chile and Argentina
ELEVATION	0–6,560 ft (0–2,000 m) asl
HABITAT	Pastures, meadows, wet forests, and coastal scrub
DIET	Frogs, toads, and lizards
REPRODUCTION	Viviparous, with litters of 6–12 neonates
CONSERVATION STATUS	IUCN Least Concern

The Chilean Short-tailed Scrub Snake is a slender snake with smooth scales, a short tail, a head just distinct from the neck, relatively small eyes, and vertically elliptical pupils. It is brown above with a series of light brown longitudinal stripes, edged with black, which run the length of the body and tail. The dorsum of the head is brown with dark flecking, and the sides and lips lighter, but interrupted by a series of black stripes which radiate from the eye.

TAENIOPHALLUS BREVIROSTRIS
SHORT-NOSED LEAF-LITTER SNAKE

(PETERS, 1863)

ADULT LENGTH
113/4–193/4 in (300–500 mm)

The Short-nosed Leaf-litter Snake is one of many small, secretive, inoffensive snakes to be found on the forest floor in northern South America. Diurnal in activity, it is found in accumulated leaf litter in pristine rainforest tree buttresses and in disturbed rainforest habitats, under cut logs in clearings, and even in areas turned over to agriculture. As with many of these smaller snake species, its natural history is poorly documented in nature. It is known to be oviparous, producing small clutches of eggs, and it feeds on small lizards such as microteiids. Due to its small mouth gape it is also likely to feed on earthworms and other soft-bodied invertebrates, but it is possible that it takes more dangerous prey, such as centipedes taken by the similar-sized genus Tantilla (shown here).

RELATED SPECIES

There are nine species of Taeniophallus snakes in South America and there are many other similar-sized genera with which they can be confused. Several congeners also occur in northern South America, the Venezuelan Leaf-litter Snake (T. nebularis), Guianan Leaf-litter Snake (T. nicagus), and Bahia Leaf-litter Snake (T. occipitalis). The forest snakes (Echinanthera) are most closely related to Taeniophallus.

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Nonvenomous
DISTRIBUTION	South America: Colombia, Venezuela, the Guianas, northern Brazil, Ecuador, Peru, and Bolivia
ELEVATION	98–6,560 ft (30–2,000 m) asl
HABITAT	Secondary and primary rainforest, forest clearings, and agricultural habitats
DIET	Lizards
REPRODUCTION	Oviparous, with clutches of 2–3 eggs
CONSERVATION STATUS	IUCN not yet assessed

The Short-nosed Leaf-litter Snake is a small species with smooth scales, a slender body, a long tail, and a narrow head with moderately large eyes and round pupils. It is gray-brown above, with five dark brown longitudinal stripes. A dark stripe though the eye separates the dorsal coloration from the pale lips, which are heavily flecked with black. The undersides are pale brown to yellow-green, while the chin may be reddish.

THAMNODYNASTES PALLIDUS
PALE MOCK VIPER

(LINNAEUS, 1758)

ADULT LENGTH
133/4–173/4 in, occasionally 233/4 in (350–450 mm, occasionally 600 mm)

The Pale Mock Viper is a widely distributed member of the genus, while some of the other species are much more localized. It is a small snake that inhabits a variety of habitats from savanna to rainforest, wetland habitats, and cultivated areas, from Colombia to Bolivia, across Amazonia, and south to Argentina. It is terrestrial, semi-aquatic, and occasionally semi-arboreal in habit, and feeds on frogs, small lizards, and arthropods, including beetle larvae. Other species of Thamnodynastes also take small mammals or fish, and this prey may also potentially feature in the diet of the Pale Mock Viper. The vertically elliptical pupils are indicative of its primarily nocturnal activity cycle, but this species is also active by day. Mock vipers are live-bearers. They are also mildly venomous, but they are not considered a snakebite risk.

RELATED SPECIES

The genus Thamnodynastes contains a further 18 species which are fairly similar in appearance, with at least six other species occurring within the range of T. pallidus. In the Amazon this is reputedly the only species with 17 scale rows at midbody. The pallidus group includes the Long-tailed Mock Viper (T. longicaudus) from northeastern Brazil, and the recently described Sertão Mock Viper (T. sertanejo). Thamnodynastes resemble the Asian mock vipers (Psammodynastes), but are not related. Their closest relatives are the pampas snakes (Tomodon) and the Brazilian Keeled Watersnake (Ptychophis flavovirgatus).

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous
DISTRIBUTION	South America: Colombia, Venezuela, the Guianas, northern Brazil, Ecuador, Peru, Bolivia, Argentina, and Uruguay
ELEVATION	0–1,640 ft (0–500 m) asl
HABITAT	Savanna, primary rainforest, wetland areas, coastal forest, and cultivated habitats
DIET	Frogs, small lizards, and arthropods
REPRODUCTION	Viviparous, litter size unknown
CONSERVATION STATUS	IUCN Least Concern

The Pale Mock Viper is a small, slender snake with keeled scales, an elongate head that is broader than the neck, and large eyes with vertically elliptical pupils. It is pale brown or light orange with a pair of very faint longitudinal stripes and light and dark flecking on the scales.

TOMODON DORSATUS
SLUG-EATING MOCK VIPER

(DUMÉRIL, BIBRON & DUMÉRIL, 1854)

ADULT LENGTH
153/4–18 in (400–460 mm)

Found from São Paulo and the Atlantic forests of southern Brazil, to Misiones in extreme northeastern Argentina, the Slug-eating Mock Viper is a specialist slug-eating snake that inhabits grasslands and forests. Live-bearing, females produce up to 26 neonates. The Slug-eating Mock Viper is generally inoffensive, with a threat posture that involves body-flattening, which, when combined with its distinctive patterning, mimics the highly venomous lanceheads (Bothrops). It is known locality as “falsa yarará” (false jararaca or lancehead). It is capable of delivering a bite that may result in pain and swelling, so caution is recommended around this species.

RELATED SPECIES

Snakes in the genus Tomodon are also known as pampas snakes and T. dorsatus occurs in sympatry with the Eyed Pampas Snake (T. ocellatus). A third species, the Bolivian Pampas Snake (T. orestes), occurs in Bolivia and Argentina. These three snakes are closely related to another mock viper genus, Thamnodynastes (shown here).

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous
DISTRIBUTION	South America: southern and southeastern Brazil, northern Argentina
ELEVATION	0–625 ft (0–190 m) asl
HABITAT	Grasslands and forests
DIET	Slugs
REPRODUCTION	Viviparous, with litters of 4–26 neonates.
CONSERVATION STATUS	IUCN not yet assessed

The Slug-eating Mock Viper is a relatively stout snake with smooth scales, a short tail, and a broad head with moderately large eyes and vertically elliptical pupils. It is dorsally pale gray or brown with darker blotches or chevrons on the dorsum and a row of pale spots along the midline. A fine dark stripe runs from the rear of the eye to the angle of the jaw.

TROPIDODRYAS SERRA
SERRA SNAKE

(SCHLEGEL, 1837)

ADULT LENGTH
351/2 in (900 mm)

The Serra Snake is found in southeastern Brazil, from Bahia to Santa Catarina, and also on Santo Amaro Island. It is endemic to the highly endangered lowland Atlantic coastal forest, and associated secondary regrowth. It is a diurnally active snake, and both terrestrial and arboreal in habit. The Serra Snake preys on small lizards, frogs, and small mammals. Juveniles wiggle their white tail tips, which resemble a worm, to lure prey within strike range, in the same manner as the unrelated death adders (Acanthophis) and cantils (Agkistrodon). The Serra Snake is oviparous but its clutch size is unrecorded.

RELATED SPECIES

A second species also occurs in southeastern Brazil, the Jiboinha (Tropidodryas striaticeps), which is much darker brown than T. serra. This species does not appear to be closely related to any other xenodontines, but comprises the sister clade to the flat-headed snakes (Xenopholis), false water cobras (Hydrodynastes), and Amaral’s Groundsnake (Caaeteboia amarali).

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous
DISTRIBUTION	South America: southeastern Brazil
ELEVATION	0–330 ft (0–100 m) asl
HABITAT	Atlantic coastal forest and secondary growth
DIET	Lizards, frogs, and small mammals
REPRODUCTION	Oviparous, clutch size unknown
CONSERVATION STATUS	IUCN Least Concern

The Serra Snake is an elongate snake with an exceptionally long tail and an arrow-shaped head, with small eyes and round pupils. It is light gray or brown in color with a vertebral pattern consisting of white-edged black squares, separated by broad brown interspaces, brown marbling on the head, a brown stripe through the eye, and a white tail tip in juveniles.

UROMACER CATESBYI
HISPANIOLAN BLUNT-NOSED VINESNAKE

(SCHLEGEL, 1837)

ADULT LENGTH
2 ft 7 in–4 ft 7 in (0.8–1.4 m)

The Hispaniolan Blunt-nosed Vinesnake is a highly arboreal and sometimes terrestrial species, found in a wide variety of habitats throughout Hispaniola (Haiti and the Dominican Republic) and on its satellite islands. It may be found in tropical rainforest but also in dry woodland, and is usually found aloft. It is an active predator of small lizards and frogs, stalking them by day in the canopy, or along branches. The Uromacer vinesnakes are the West Indian equivalent of Asia’s Dryophis, Africa’s Thelotornis, and mainland America’s Oxybelis; that is, elongate, camouflaged, diurnal, rear-fanged treesnakes. These genera may represent examples of convergent evolution— unrelated species that look and act similarly in different locations. Although venomous, these snakes are not considered a snakebite risk. Mark Catesby (1683–1749) was an English naturalist who traveled widely in the Americas.

RELATED SPECIES

There are eight subspecies of Uromacer catesbyi in Haiti and the Dominican Republic, with endemic island populations on Île de la Tortue (U. c. scandax), Île de la Gonâve (U. c. frondicolor), Îles Cayemites (U. c. cereolineatus), and Île-à-Vache (U. c. insulaevaccarum), all of which are Haitian islands, and Isla Saona, Dominican Republic (U. c. inchausteguii). There are also two other species of Hispaniolan vinesnakes, both with much longer snouts than U. catesbyi: the Southeast Hispaniolan Vinesnake (U. frenatus) and Hispaniolan Long-nosed Vinesnake (U. oxyrhynchus). Both may be other colors apart from green.

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous
DISTRIBUTION	West Indies: Hispaniola (Haiti and Dominican Republic)
ELEVATION	0–5,000 ft (0–1,525 m) asl
HABITAT	Dry forest to tropical rainforest
DIET	Lizards and frogs
REPRODUCTION	Oviparous, with clutches of up to 5 eggs
CONSERVATION STATUS	IUCN not yet assessed

The Hispaniolan Blunt-nosed Vinesnake is a slender-bodied snake with smooth scales, a long, prehensile tail, and a narrow, pointed head, though not as pronounced as its congeners, with large eyes and round pupils. Adults are green, with or without a white, light green, or blue ventrolateral stripe, while juveniles may be brown or gray with green heads.

XENODON DORBIGNYI
D’ORBIGNY’S HOGNOSE SNAKE

(BIBRON, 1854)

ADULT LENGTH
Male
153/4–193/4 in (400–500 mm)

Female
153/4–233/4 in, occasionally 371/2 in (400–600 mm, occasionally 950 mm)

D’Orbigny’s Hognose Snake is a generally inoffensive snake that actively mimics highly venomous lanceheads, such as the Urutu (Bothrops alternatus), for protection, and it is often called “falsa yarará” (false jararaca or lancehead). It also buries its head under its coils and exposes the red and black underside of its tail, to intimidate potential predators with coralsnake colors. D’Orbigny’s Hogsnake Snake is found in southern Brazil, Paraguay, Uruguay, and Argentina as far south as Río Negro Province. It usually inhabits open sandy grassland, rocky hillsides, or beach-type habitats where it can quickly burrow under logs or rocks. It preys on lizards, frogs, tadpoles, fish, and beetle larvae, and although mildly venomous, is not considered a snakebite risk. Alcide d’Orbigny (1802–57) was a French naturalist and traveler who lived in Argentina.

RELATED SPECIES

The six species of South American hognose snakes, formerly in genus Lystrophis, are now placed in Xenodon, although some authors retain the original generic name. They resemble the North American hognose snakes (Heterodon), but are more closely related to the false coralsnakes and groundsnakes of genus Erythrolamprus (shown here). The Mato Grosso Hognose (X. matogrossensis), Beautiful Hognose (X. pulcher), Half-banded Hognose (X. semicinctus), and Jan’s Hognose (X. histricus) are dorsally banded or patterned red, black, and white, as coralsnakes mimics, while Natterer’s Hognose (X. nattereri) is blotched with light and dark brown.

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous
DISTRIBUTION	South America: southern Brazil, Paraguay, Uruguay, and Argentina
ELEVATION	No elevations available
HABITAT	Open grassland, rocky hillsides, sandy habitats, and pinelands
DIET	Lizards, frogs, tadpoles, fish, and insect larvae
REPRODUCTION	Oviparous, with clutches of 3–15 eggs
CONSERVATION STATUS	IUCN not yet assessed

D’Orbigny’s Hognose Snake is a relatively stout snake with smooth scales, a short tail, and a short, broad head with a distinctive upturned snout and large eyes with round pupils. It is dorsally pale gray with several dark gray chevrons on the head that continue onto the body as three series of large ocelli markings. The undersides are pale with a black checkerboard pattern and a heavy infusion of red pigment.

XENODON RABDOCEPHALUS
NORTHERN FALSE LANCEHEAD

(WIED-NEUWIED, 1824)

ADULT LENGTH
Male
233/4–271/2 in (600–700 mm)

Female
233/4–381/4 in (600–1,000 mm)

The Northern False Lancehead is the only Xenodon in Mexico and Central America. It also occurs across northern South America. It inhabits a wide range of habitats, from tropical rainforest to dry forest, at low and mid-montane elevations, usually near water. Although it superficially resembles the numerous pitvipers, with which it occurs in sympatry, it has round, rather than vertical, pupils and it lacks the pitvipers’ heat-sensitive pits. This species is a toad specialist, even feeding on the large, poisonous cane toad. Toads habitually inflate themselves to avoid predation but the Northern False Lancehead easily deflates its prey by puncturing the body cavity and lungs with its long rear fangs. Frogs or tadpoles are taken less often. Bites to humans result in swelling, localized pain, and extensive bleeding.

RELATED SPECIES

Aside from the South American hognose snakes, formerly included in Lystrophis, there are also six species of false lanceheads in the genus Xenodon, several of which were previously included in the genus Waglerophis. The northern South American species include the Amazonian False Lancehead (X. severus), Merrem’s False Lancehead (X. merremi), and Werner’s False Lancehead (X. werneri), while Günther’s False Lancehead (X. guentheri) and Neuwied’s False Lancehead (X. neuwiedii) are found farther south.

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Rear-fanged, mildly venomous
DISTRIBUTION	North, Central, and South America: southern Mexico, to the Guianas, Brazil, and Bolivia
ELEVATION	0–6,230 ft (0–1,900 m) asl
HABITAT	Rainforest, dry deciduous forest, evergreen forest, and low montane forest, especially near water
DIET	Toads and frogs
REPRODUCTION	Oviparous, with clutches of 5–15 eggs
CONSERVATION STATUS	IUCN not yet assessed

The Northern False Lancehead is a stout- bodied, viperine snake with smooth scales, a short tail, and a broad head with small eyes and round pupils. Its patterning comprises alternating irregular, white-edged light and dark brown bands, with a dark brown arrow marking on the dorsum of the head. The undersides are cream or gray with extensive dark mottling.

XENOPHOLIS SCALARIS
LADDER FLAT-HEADED SNAKE

(WUCHERER, 1861)

ADULT LENGTH
133/4–153/4 in (350–400 mm)

The flat-headed snakes are terrestrial or semi-fossorial species that inhabit primary and secondary rainforest, especially in association with small rainforest pools. The Ladder Flat-headed Snake may be either diurnal or nocturnal in habit. It is found across northern Amazonia, from Colombia to the Guianas and Brazil, and south to Peru and Bolivia. Many small leaf-litter-dwelling snakes are poorly documented in nature, due to the infrequency of encounters and their secretive habits, and this species is no exception. They are nonvenomous predators of small frogs. Females are oviparous, with clutches of four eggs on record. The defense of the Ladder Flat-headed Snake involves body-flattening to the thinness of a ribbon, a tactic intended to make the snake appear larger than it is in reality, and hopefully deter predators.

RELATED SPECIES

Two other species are recognized, the Undulated Flat-headed Snake (Xenopholis undulatus), from eastern and southeastern Brazil, and Paraguay, and Werdings’ Flat-headed Snake (X. werdingorum), from eastern Bolivia and possibly southwestern Brazil. The flat-headed snakes are related to the Jiboinha and the Serra Snake (Tropidodryas) and Amaral’s Groundsnake (Caaeteboia amarali).

FAMILY	Dipsadidae: Xenodontinae
RISK FACTOR	Nonvenomous
DISTRIBUTION	South America: Colombia, the Guianas, Brazil, Ecuador, Peru, and Bolivia
ELEVATION	0–4,920 ft (0–1,500 m) asl
HABITAT	Primary and secondary rainforest
DIET	Juvenile frogs
REPRODUCTION	Oviparous, with clutches of 4 eggs
CONSERVATION STATUS	IUCN Least Concern

The Ladder Flat-headed Snake is a smooth-scaled species with a short tail and a flattened head, just distinct from the neck, with small eyes and vertically elliptical pupils. It is dorsally light red-brown with a black vertebral stripe and a series of black blotches along either side of the middorsal line, which may fuse to form short cross-bands, hence “ladder.” The lips and lower flanks are yellow, while the venter is white.

AMBLYODIPSAS POLYLEPIS
COMMON PURPLE-GLOSSED SNAKE

(BOCAGE, 1873)

ADULT LENGTH
Male
193/4–213/4 in (500–550 mm)

Female
2 ft 4 in–3 ft 7 in (0.7–1.1 m)

The Common Purple-glossed Snake has a wide distribution, from Somalia to KwaZulu-Natal, South Africa, and westward to Angola and Namibia. It shows a preference for wet grassland and lowland forests, but is often only seen after rain. It feeds on fossorial reptiles, including blindsnakes, legless skinks, and amphisbaenians (worm-lizards). Although this species is venomous, prey may be constricted before it is swallowed, suggesting the venom is not especially toxic. Although purple-glossed snakes are not considered dangerous to humans, their venom composition, yield, and toxicity have not been studied, and the lack of snakebites may be due to their placid nature. They prefer to bury their heads under their coils rather than bite, and when threatened by a predator will elevate the tail as a mock head, to draw attention away from the real head.

RELATED SPECIES

Most of the range of Amblyodipsas polylepis is occupied by the nominate subspecies, while a second subspecies (A. p. hildebrandtii) is found from Tanzania to Somalia. The genus Amblyodipsas contains a further eight species, from the Western Purple-glossed Snake (A. unicolor) of West and Central Africa, to the Natal Purple-glossed Snake (A. concolor) in South Africa. Purple-glossed snakes may be confused with the Natal Blacksnake (Macrelaps microlepidotus) and the venomous side-stabbing or stiletto snakes (Atractaspis).

FAMILY	Lamprophiidae: Aparallactinae
RISK FACTOR	Rear-fanged, mildly venomous: venom composition unknown
DISTRIBUTION	Southern and East Africa: South Africa, Swaziland, Mozambique, Malawi, Zimbabwe, Zambia, Namibia, Angola, southern DRC, Kenya, Tanzania, and Somalia
ELEVATION	0–4,920 ft (0–1,500 m) asl
HABITAT	Moist savanna grasslands and lowland forests
DIET	Fossorial snakes, lizards, and amphisbaenians
REPRODUCTION	Oviparous, with clutches of 6 eggs
CONSERVATION STATUS	IUCN not listed

The Common Purple-glossed Snake is, as its common name suggests, a highly glossy snake with a uniform purple-brown to black coloration. It has a relatively stout body, a blunt tail, and a dorsally compressed head with a slightly pointed snout and set-back lower jaw, for burrowing. The eyes are very small.

APARALLACTUS CAPENSIS
CAPE CENTIPEDE-EATER

SMITH, 1849

ADULT LENGTH
8–113/4 in (200–300 mm)

The Cape Centipede-eater is a widely distributed snake, occurring down the eastern side of East and southern Africa, from Zambia to the Eastern Cape of South Africa, and west to the Caprivi Strip of Namibia, but it is absent from southern Mozambique. It inhabits wet savanna and lowland woodland, and is especially common around termitaria. Its prey consists entirely of centipedes, which are bitten and eventually killed by multiple bites. If the centipede turns and bites the snake, the snake will release its prey, but start again shortly afterward and eventually swallow the centipede headfirst. Centipede-eaters will struggle and try to bite if handled but their mouths are small and their fangs short, and no ill effects have been documented. Their venom is unstudied but not considered highly toxic to humans.

RELATED SPECIES

There are 11 species of Aparallactus in sub-Saharan Africa, from the Western Black Centipede-eater (A. niger) of West Africa, to the Malindi Centipede-eater (A. turneri) of coastal Kenya and the Usambara Centipede-eater (A. werneri) of Tanzania. Aparallactus capensis occurs in sympatry with the Plumbeous Centipede-eater (A. lunulatus) and Eastern Black Centipede-eater (A. guentheri). Through its range four subspecies are recognized.

FAMILY	Lamprophiidae: Aparallactinae
RISK FACTOR	Rear-fanged, mildly venomous: venom composition unknown
DISTRIBUTION	Southern and East Africa: South Africa, Lesotho, Swaziland, central Mozambique, Zimbabwe, Zambia, eastern Botswana, Namibia (Caprivi Strip), and coastal Tanzania
ELEVATION	0–5,580 ft (0–1,700 m) asl
HABITAT	Wet savanna grassland, lowland woodland, and termitaria
DIET	Centipedes
REPRODUCTION	Oviparous, with clutches of 2–4 eggs
CONSERVATION STATUS	IUCN Least Concern

The Cape Centipede-eater is a slender snake with shiny, smooth scales and a head no wider than the body. It is yellow or red-brown above, paler on the flanks, becoming off-white below. Its most defining characteristic is the black cap that covers the head and extends onto the neck, where it forms a band, contrasting with the white of the posterior labial scales.

CHILORHINOPHIS GERARDI
GERARD’S TWO-HEADED SNAKE

(BOULENGER, 1913)

ADULT LENGTH
153/4–193/4 in (400–500 mm)

Gerard’s Two-headed Snake is so-called because its tail closely resembles its head, and when it is threatened it will hide its head and elevate and writhe its tail to distract its enemy, giving the impression of a head at either end. This is different from true “two-headed” or dicephalic snakes, which are birth deformities with two heads at the same end of a single body (see here). Gerard’s Two-headed Snake is secretive, fossorial, and nocturnal, and only seen on the surface after rain. It feeds on slender fossorial skinks, amphisbaenians (worm-lizards), and small snakes, including conspecifics. Its preferred habitat is savanna grasslands on sandy substrates, but it may also be excavated in agricultural fields. Nothing is known of its venom, but its mouth is small and probably incapable of delivering a snakebite.

RELATED SPECIES

Two subspecies are recognized, the nominate form (Chilorhinophis gerardi gerardi) from Zimbabwe and eastern Zambia and a northern subspecies (C. g. tanganyikae) from northern Zambia, southern Democratic Republic of the Congo, and Tanzania. The genus Chilorhinophis also contains a second species, Butler’s Two-headed Snake (C. butleri), from South Sudan, Tanzania, and also Mozambique, where the population was formerly treated as a separate species (C. carpenteri).

FAMILY	Lamprophiidae: Aparallactinae
RISK FACTOR	Rear-fanged, mildly venomous: venom composition unknown
DISTRIBUTION	East Africa: Tanzania, Zambia, Zimbabwe, and southern DRC
ELEVATION	1,920–4,270 ft (585–1,300 m) asl
HABITAT	Sandy savanna grasslands, and fields
DIET	Fossorial lizards and amphisbaenians, and small snakes
REPRODUCTION	Oviparous, with clutches of 6 eggs
CONSERVATION STATUS	IUCN not listed

Gerard’s Two-headed Snake is an elongate snake with a short tail and a small head, which is indistinct from the neck. The body is golden yellow with three bold black longitudinal stripes, the head is black with yellow spots and a black nape band around the neck, and the tail is black above and light blue or white on the flanks. The venter is orange, while the throat is white.