chapter three

crafty critters

which creature can drop its tail off?

Many types of lizard, including skinks, have the ability to drop off their tails when threatened by a predator. Their tails have special fracture points, so that, if they are being chased or grabbed by a predator, their tail will drop off. Amazingly, the tail will carry on wriggling for several minutes, confusing the predator and creating the illusion of a continued struggle. With luck, this should buy the lizard enough time to escape.

In the weeks after losing one tail, the lizard will usually be able to grow another, although this one will contain cartilage rather than bone and will often be smaller than the original tail. Sometimes, if the first tail doesn’t drop off fully, the new tail will grow alongside it, giving the lizard the freaky appearance of having two tails.

Glass lizards do something even more surprising. Like skinks, they drop off their tails when threatened, but when a glass lizard’s tail drops off, it breaks into a number of pieces, shattering like glass. A glass lizard’s tail makes up as much as two-thirds of the creature’s length, so it is a shocking and extraordinary sight when the tail drops off and shatters, since it looks as if the creature has spontaneously smashed into pieces (and technically it has). Often the broken pieces of the tail will continue to twitch, while the glass lizard itself remains motionless, confusing and distracting the predator, and helping the lizard make its escape.

why do moles squeeze earthworms?

Moles are cute, furry, burrowing mammals that are around 6 inches (15 cm) long and weigh just 3.5 ounces (100 g). They spend most of their lives foraging in a network of underground tunnels, through which they burrow at incredible speed. Moles have short, powerful legs and very broad front feet, which they use for digging. Just one small mole can dig its way through an amazing 46 feet (14 m) of soil in only one hour.

Moles have an active, high-energy lifestyle, which means they usually need to eat their own weight in food each day. Their diet can include insects, spiders, grubs, and even an occasional mouse, if it comes too close, but their main foodstuff is earthworms. When it finds an earthworm, a mole will pull it through its paws, squeezing it tightly, to force out any earth and mud from the worm’s guts.

Then the mole will either eat the worm or keep it for later. Moles have a toxin in their saliva that can paralyze earthworms, so they often bite off the worm’s head, paralyzing but not killing it. They store the headless worm in a specially constructed underground larder. Scientists have found well-stocked mole larders containing as many as a thousand paralyzed earthworms.

how do fireflies tell fire-lies?

Fireflies are celebrated for their wonderful ability to produce cold light (meaning that there is no heat emitted) through a process called bioluminescence, in which the light is produced by the reaction of two chemicals in the presence of oxygen. Female fireflies use these green, yellow, and pale red lights to attract a mate. They flash their lights in a distinct pattern that is unique to their species and acts as a signal to nearby males. This system helps the males and females of each species to find eligible partners and to avoid wasting time paying visits to fireflies of other species.

However, some crafty female fireflies have found a way to subvert this system. Photuris fireflies, which are also known as “femme fatale fireflies,” can copy the flash patterns of other species, in order to attract these males. When the male flies down, he is expecting to find a friendly and receptive female of his own species. Instead, he finds a hungry femme fatale, who quickly kills him and eats him for dinner.

which spider looks like a blob of bird poo?

There is a spider, appropriately known as the bird-dropping spider, that looks just like a lump of bird poo. It has a gray and white body, and it is usually found with its legs tucked in, curled up in a ball, sitting on a leaf, just where a blob of bird muck might land. It may not be pretty, but this disguise is far from unique, as there are also a number of caterpillars that use a similar camouflage.

Why would any creature choose to look like bird poo? Well, first, it protects them from predators, as this spider’s most likely attackers are birds, which naturally avoid eating the feces of other birds. Second, it helps them hunt food of their own, as the spider’s prey are unlikely to see any threat in the common sight of a splodge of bird mess, and so may come far closer than is good for them.

which spider hunts like a gaucho?

Gauchos are South American cowboys who traditionally use a special technique for bringing down cattle. They use a throwing weapon called a bolas, which consists of a piece of rope with wooden or metal balls at each end, and another ball tied to the middle. Gauchos can throw bolas with great skill at the legs of fleeing cattle, tying up their legs and making them trip and fall.

In many parts of the world, including South America, lives a spider that uses a similar technique to snare its prey. The bolas spider is about the size of a pea, and colored black and white. When darkness starts to fall, the spider goes hunting. First it lays a line of nonsticky silk on the underside of a twig or leaf. Then it hangs from this line, using two of its legs. Next it spins a line of sticky silk, about 1 inch (2.5 cm) long, with a sticky blob of silk at the end, like the weighted end of the bolas. Now the spider simply hangs there, dangling its line, which glints in the twilight. It will stay like this for up to fifteen minutes, and if it hasn’t caught anything by then, it will reel in its line and eat it, perhaps because the line will have lost its stickiness.

In these first few hours of the night, the spider is hunting for cutworm moths. Eventually one will appear, flying straight for the spider’s dangling line. The moth may be attracted by the light glinting off the sticky silk. It is also attracted by the pheromones that the spider emits, which are an exact chemical match for the perfume used in cutworm moth courtship. As the moth gets closer, the spider swishes the bolas, swiping the moth into its mouth.

A few hours later, these moths are no longer active, so the spider pulls in the line, eats it, and takes a rest. At midnight, it goes hunting again, but this time it has a new target: a moth called the smoky tetanolita. The spider now begins to produce a different pheromone, this one designed to attract its new prey, like a skillful fisherman varying his bait to catch a different type of fish.

which spider builds a life-size model of itself?

Many types of spiders decorate their webs, and these decorations seem to serve a number of functions. Some spiders use silk ornaments to strengthen the web. Other decorations seem designed to make the web more visible, either to deter large animals from accidentally walking into the web and destroying it, or to attract prey. Scientists in Taiwan have recently discovered a fascinating and unique use of web decorations, after observing one type of spider building a life-size replica of itself as a decoy to fool predators. No other creature is known to build a model of itself in this way.

A number of species of orb spider are known to decorate their webs with various types of material, including discarded egg sacs, plants, and the remains of prey. Until recently, this kind of decoration was believed to be used as camouflage. But scientists observing the spiders found that wasps were actually more likely to attack decorated webs rather than plain ones, suggesting that the decorations could serve no useful purpose as camouflage.

Observing another species of orb spider, Cyclosa mulmeinensis, on Orchid Island off the southeast coast of Taiwan, the scientists noticed that, when decorating its web, it built pellets using egg sacs and dead insect bodies that were exactly the same size and shape as its own body. These pellets would appear to wasps to be the same color as the spider’s body and to reflect light in the same way. When wasps attacked the web, more often than not they would attack the decoy rather than the spider, suggesting that while these decoys might attract more wasps than an undecorated web, they nonetheless made the spider safer overall.

do fish fish for fish?

There’s a type of fish that has a very crafty technique for catching its prey. It is called an anglerfish because it attracts its prey using bait just like a fisherman. However, the bait it uses is its own tongue, which is long and thin and wriggles like a worm. The anglerfish sits on a reef, with its mouth wide open and its tongue wriggling, looking just like a juicy, tasty worm. When a curious fish comes closer, looking for a snack, instead it finds itself being sucked into the anglerfish’s mouth and becoming a snack itself.

The anglerfish is the only fish that is known to use this technique, but there is also a kind of turtle that does something very similar. The alligator snapping turtle is a big, ferocious predator that can weigh as much as 220 pounds (100 kg). Its jaws are hooked and have a sharp cutting edge made of horn. It is so fierce that if you approach one on land, it may well attack you. It is perhaps justified in being confident in its strength, since it and its near relatives have been proven to be among the most resilient and enduring life-forms on Earth. The alligator snapping turtle is a close descendant of an ancient tortoise called Triassochelys, or the Triassic turtle, whose remains have been found in rocks of the Triassic age, from around 245 million years ago.

The alligator snapping turtle lies at the bottom of lakes with its mouth open, using its tongue to tempt passing fish. Like the anglerfish, the snapping turtle has a long, thin, bright red tongue, which wriggles in such a way as to perfectly mimic a worm. The turtle’s technique is slightly different from that of the anglerfish. Instead of sucking its prey into its mouth, it snaps its powerful jaws shut, often chopping the fish in half.

how do japanese crows crack open walnuts?

Carrion crows are found throughout the forests of Japan. These forests produce an abundance of walnuts, which could make a tasty and nutritious treat, but until recently carrion crows have never been able to crack them open, because their beaks are not strong enough. Many birds do manage to crack open similarly obstinate foodstuffs by dropping them from the air—for example, bearded vultures live mainly on a diet of bone marrow, which they get by dropping bones from a great height, cracking them open. The similarly ingenious Egyptian vulture likes to eat ostrich eggs, which are full of nutrients, but their shells are very thick and difficult to crack open. The solution these vultures have discovered is to drop rocks onto the eggs, breaking the shells. Walnuts can be cracked open by being dropped, but they have to be dropped as many as fifty times, so it’s a lot of work for a small snack.

In 1990, the ingenious carrion crows of Sendai City came up with an impressive solution. They started using cars. The birds wait at the city’s traffic lights, holding a walnut in their beaks. When the lights turn red, they swoop down and place the nut in front of a car’s tires. When the lights turn green, the cars drive over the nuts, cracking them open. The birds wait for the lights to turn red again, then hop back down into the road and pick up their dinner. This behavior is slowly spreading, as other crows observe it happening and then take it up themselves. One of the most fascinating aspects of this behavior is that the crows seem to have learned to use traffic lights and to understand something of how they work, as other stretches of road would be too dangerous.

why do birds feign injury?

There are a number of birds, such as lapwings and plovers, that, rather than build elaborate nests in trees, simply lay their eggs on open ground—on marshes, grasslands, or beaches. This is a simpler solution than building an intricate nest, but it means the eggs are more vulnerable to predators such as foxes. One way to protect the eggs is to camouflage them, and so birds that nest in this way tend to produce eggs with mottled patterns, to make them invisible against the gravelly ground. When the chicks hatch, the parent birds carry away the broken bits of shell, so that their shiny white interiors don’t reveal the location of the nest.

Nonetheless, this camouflage is an imperfect solution. If a predator gets close to the nest, it’s unlikely to be deceived, so the mother will try a different trick: she will feign injury, to distract the predator from the nest. When predators approach, lapwings and plovers hop away from their nests, dragging a wing along the ground, as if they are hurt. To ensure that they attract the predator’s attention, they may start screaming, as if in pain or distress.

A predator such as a stoat is likely to be far more tempted by the prospect of a fully grown adult bird than a handful of eggs or chicks, and so it follows, getting gradually dragged away from the location of the nest. As the predator gets closer to the mother, at the last minute she suddenly flies away, as if she has been miraculously healed. However, the stoat has by now been led so far away from the nest that, even if it had spotted the eggs in the first place, it now has no way of retracing its steps and finding them again, particularly given the kinds of nondescript, uniform landscapes, such as marshes and shingle beaches, where these birds nest.

Other birds seem to have developed this trick to an even more advanced degree. Instead of feigning injury, purple sandpipers on the Arctic tundra run away from their nests with both wings trailing behind, raising their feathers, while making a squeaking sound that bears no resemblance to their usual calls. The effect of this is that they look and sound just like a scuttling mouse or lemming, both of which are particularly tempting prey for Arctic foxes, the most likely audience for this performance. In the United States, the green-tailed towhee also tries to mimic another kind of appealing prey. If a coyote approaches, it will run from its nest while lifting its tail. This at first glance makes it look a bit like a chipmunk, which is the main prey of local coyotes.

do animals tell lies?

A number of bird species are known to deceive one another for their own gain, taking advantage of the communal sentinel system by which many birds depend on one another for their safety. Often an area of woodland or forest will contain many species of bird of a similar size, which will all be similarly threatened by the arrival of a larger predator such as a hawk. Consequently, birds have developed a wonderfully resourceful sentinel system, in which the first bird to spot the danger will sound the alarm by giving a particular type of call, which is usually written as “seet.” It is a soft, short, high-pitched call, which is clear and easily understood but difficult to locate, thus minimizing the danger for the sentinel. Obviously, an alarm call that significantly endangered the signaler would be of very limited value. Many hedgerow birds, including finches, thrushes, and tits, all use a “seet” call, which is simultaneously understood by birds of different species, like an international language. On hearing the “seet” call, all the birds in the area will drop what they are doing, find shelter, and remain quiet.

But this system also presents opportunities for deception. In the Amazonian rain forest, communities of small birds operate a sentinel system while they rummage through the leaf litter looking for tasty insects. Here, two species of bird often act as sentinels: antshrikes, which keep watch under the shade of the canopy, and shrike tanagers, which act as lookouts above the canopy. Doing this job means that these birds have less time to forage for insects, so the other birds reward them by letting them have some of the insects that they find. Sometimes, though, the sentinels will lie. If they spot a particularly tasty-looking insect being dug up, they may give a warning call, even though there is no actual danger. The other birds will flee for safety, and the sentinel will come and grab the insect.

Various monkey species use a similar system of alarm calls. Vervet monkeys have at least five different calls, which give detailed warnings as to which direction the danger is coming from, whether it is from the ground or the air, and how urgent and threatening the danger is. Again, however, sometimes the sentinels tell lies. In one example, researchers witnessed one monkey watching another monkey digging up a large root. Just as it was about to pull this tempting prize from the ground, the sentinel shouted the alarm for “snake,” which sent the other monkey scuttling up into the trees for safety. Then the crafty lookout came down and grabbed the tasty root, with no snake in sight.

In a more detailed study, capuchin monkeys were found to do the same thing. In an Argentinean national park, scientists found that the monkeys sounded alarm calls ten times more frequently when pieces of banana were placed in the open. In other words, when there was a tasty incentive to send the other monkeys fleeing for safety, the sentinel monkeys were much more likely to give an alarm call, even though the level of danger was constant.

Of course, the two main preoccupations of most creatures are food and reproduction, and as we might expect, there are also examples of animals that tell lies for the purpose of attracting a mate. For instance, male domestic chickens, in order to tempt a female, are known to produce a specific type of call when they have found food. Sometimes these chickens give this call deceptively, when in fact they have no food, purely to lure the female to come closer.

which bird is an expert impressionist?

In the forests of southern Australia lives a bird with an extraordinary talent. It is the male Australian lyrebird, and it sings one of the most beautiful and complex songs of any bird. When it’s time to mate, the female lyrebirds make a tour of the males’ display mounds in the forest, to inspect their potential partners. The males are extraordinary-looking, with cream-colored, fanlike tail feathers. When the males display, they bend these tail feathers forward, completely covering themselves.

At the same time, they sing an incredible song, or rather a variety of songs, which are not only pleasing to the ear but also full of clever mimicry and references. The male lyrebird’s courtship song incorporates an amazing variety of trills and warbles, as well as mimicking the songs of almost every other bird in the neighboring area. Ornithologists are said to be able to recognize the calls of more than a dozen different birds in the lyrebird’s repertoire. Presumably, this talent has evolved in response to the female’s desire for ever more complex and varied aural stimulation.

Perhaps the most impressive aspect of the lyrebird’s performance is that these songs are not just inherited traits, passed down through the generations. Rather, each individual bird has a talent for spontaneous mimicry and can quickly learn and incorporate new sounds. This is demonstrated by the great speed with which these birds incorporate the sounds of human activity into their songs when their territories are close to human settlements. Lyrebirds observed near populated areas have been known to incorporate the sounds of chain saws, car alarms, barking dogs, camera motors, car horns, welding machines, and crying babies into their recitals. Some are also said to have learned tunes that they’ve overheard being played by musicians.

why do owls collect poo?

A large proportion of a burrowing owl’s diet consists of dung beetles, and so these wise old birds have come up with an ingenious way to attract their prey. Dung beetles, of course, love nothing more than poo; in fact, their whole society is based on it. Taking advantage of this, burrowing owls collect the droppings of cows, horses, and other large mammals and carry them back to their burrows, lining their nests with the smelly stuff. This bait is enough to attract the dung beetles, which scuttle their way to the burrow’s entrance, hoping for a tasty meal. Instead, they soon find that the hungry owl waiting there deserves its reputation for intelligence.

which bird turns itself into a parasol?

Green-backed herons are perhaps the craftiest fishermen of all the birds, as they use a number of sophisticated techniques to catch their prey and are also able to quickly learn new tricks. One of the heron’s clever techniques is to turn itself into a parasol. On a hot day, a wading heron may spread its broad wings, creating a patch of cool shady water in the lake or river where it is hunting. Remaining quite still, the heron then waits for a fish to swim into this pleasant patch of shade, before grabbing it in its beak.

This is merely one of this particular heron’s impressive range of fishing techniques. In Japan, green-backed herons seem to have recently learned to fish with bait, having presumably picked up the habit from observing humans. In a public park, where people come to feed the exotic fish, herons have started picking up morsels of bread and dropping them onto the surface of the lake, as if feeding the fish. When a hungry fish comes to the surface to take the bread, the heron grabs it in its beak. Herons have also been seen using insects as bait in the same way.

The heron also uses another, even more sophisticated tactic. As fishermen will tell you, fish are naturally inquisitive. It is not always necessary to offer food to get them to rise to the surface; something shiny or colorful will do the trick just as well. A bird called the little egret attracts fish in this way. It has black legs with bright yellow feet. To attract fish, the little egret shakes one of its brightly colored feet on the surface of the water, tempting fish to come to investigate. The green-backed heron has also learned to do something similar, dangling small feathers on the water’s surface, and this also seems to work.

which bird can chat with badgers?

The honeyguide is a small, dull-looking bird, distantly related to woodpeckers; it is found in Asia and Africa. Despite the name, it isn’t really honey that the honeyguide likes to eat. Rather, it eats beeswax and bee larvae, as well as other insects. In fact, it is the only animal of any kind that is known to be able to digest wax. In Asia, bees tend to nest in relatively open, unprotected sites, hanging from the ceiling of a cave, for example. Honeyguides have no trouble raiding these nests.

African bees tend to choose more secluded, inaccessible sites for their nests, such as holes in trees, or spaces hidden between rocks. Honeyguides can’t get to these nests, so they recruit the help of a creature called a honey badger, also known as a ratel. Ratels do love honey, and they have the necessary claws and physical strength to break into the kind of secluded nests that honeyguides are adept at finding but unable to crack open. Amazingly, these two very different species have learned to work together in a mutually beneficial partnership.

When the honeyguide finds a ratel, it perches nearby and calls to it, giving a distinctive, chattering cry. The ratel responds with a series of guttural growls and begins to follow the bird. The honeyguide flies off, frequently stopping, calling, and fluttering its tail at the ratel to make sure it’s still following, while the ratel answers these calls by growling back. Eventually the bird reaches the hive and communicates this to the ratel by climbing to a higher perch and giving a different call. The ratel apparently understands what this means—that the nest is nearby—and begins digging for it. Once the ratel finds the nest, the bees attack it, swarming around its head and stinging it; the ratel responds by farting into the nest hole, and the smell it produces must be as unbearable to bees as it is to humans, as most of the bees now flee. Using its claws, the ratel tears out the honeycombs and carries them away. The honeyguide now swoops down to forage in what’s left of the wreckage of the nest, feasting on the dead bees, grubs, and honeycomb.

Ratels are not the only animals that honeyguides have learned to work with. They also collaborate with humans, specifically the Boran people of East Africa. When they want to find honey, the Boran bushmen give a specific whistle, known as a fuulido , to summon the honeyguide, which will then lead them to a secluded bees’ nest, just as it would lead a ratel. According to tradition, once the bushmen are finished, they leave a gift of honey for the honeyguide, to thank it for its help.

what is nature’s most unlikely impressionist?

One candidate must be the tiny blister beetle larva, which manages to impersonate a creature hundreds of times its size. Or, rather, it manages to do so collectively, with the help of hundreds of its siblings. A group of blister beetle larvae group together in a beelike shape and produce an accurate enough collective impression of a female digger bee to fool a randy male bee into trying to mate with them.

Blister beetles are found in the Mojave Desert in the western United States. The females lay their eggs on the sand, where they hatch as tiny, hairy, black larvae that look nothing like their parents, or indeed like any other beetle. These larvae stick together as a group and climb the nearest grass stem, where they huddle together as a single, shiny mass. This mass looks roughly the same size and shape as a female digger bee, although to our eyes there would seem to be little other resemblance. They also emit the same chemical pheromone as a receptive female digger bee.

Within minutes, this impersonation is usually good enough to attract a male digger bee, which will come in to land on the group and attempt to mate with them. At this moment, they suddenly disperse and climb onto his body, gripping him with their tiny claws.

At this point, the male flies off, no doubt somewhat baffled at the sudden disappearance of his intended mate, but perhaps unaware that he’s now wearing what looks like a dinner jacket made of tiny black beetle larvae. With luck, however, he soon finds another female, and this one may even be a real bee. As he lands on her, ready to begin copulation, the beetle larvae quickly transfer themselves onto her body. They are now on the home stretch of their unlikely journey. The fertilized female now returns to her nest, where she has filled a number of open cells with pollen. Here, the beetle larvae dismount, to enjoy their new home, where they will grow in safety, feasting on the bees’ eggs and honey, before emerging as adult blister beetles.

how do stick insects get ants to incubate their eggs?

Stick insects like to keep things simple. Often, female stick insects don’t even bother involving the male in the business of reproduction. Instead, a female will simply produce eggs all by herself, in a process of asexual reproduction called “parthenogenesis,” in other words, genesis with no Pa. Then, rather than care for the eggs, the stick insect mother simply lets them drop to the ground. Yet despite this apparently lax approach to child rearing, the species endures, thanks to a number of cunningly designed evolutionary traits.

In Australia, one species of stick insect, called the spiny leaf insect, feeds almost exclusively on the leaves of the casuarina tree. These trees produce small, fleshy seeds that are rich in oil and nutrients. For this reason, harvester ants collect these seeds, which they store safely in their nests, ready to be eaten. The female spiny leaf insect takes advantage of this by producing eggs that are small, round, and finely ridged, exactly like casuarina seeds. The harvester ants can’t tell the difference, so they collect the insect’s eggs along with the seeds and store them all together. Later, when the ants come to eat their stores, they find that only some of the seeds have sprouted tasty attachments, so they leave the eggs alone to grow in safety underground.

Eventually, the eggs hatch, and we might imagine that this would put the infant stick insects in considerable danger. They are, after all, uninvited intruders in the ants’ nest. However, the stick insect’s gift for mimicry protects the infants once again, since, when they hatch, they look and move exactly like newborn ants. Consequently, the ants allow them to walk out of the nest unmolested, after which they climb up the casuarina tree to start the process again.

are sheep as dumb as they look?

Well, it’s true that sheep don’t possess the most thrilling intellects of the animal kingdom, but they perhaps deserve more credit than they are given. For one thing, they have excellent memories. They can remember the faces of sheep and people for up to two years. They can also be trained to remember the rocks and streams that mark the boundaries of their territory, and then pass on this information to their young. This is obviously an extremely useful trait from a shepherd’s point of view. Intriguingly, flocks of sheep will retain this information for centuries, passing it on from one generation to the next.

Sheep have also displayed some rather more daring talents. Recently, for example, sheep in Yorkshire, England, have taught themselves how to roll across cattle grids to raid the local villagers’ gardens. Daredevil sheep have been observed taking a long run-up, and then rolling across the hoof-proof grids in a ball, like an SAS commando. Since these grids are about 8 feet (2.5 m) wide, this is no mean feat. The hungry sheep are also said to have learned to climb or hurdle over fences up to 5 feet (1.5 m) high. So you see, not all sheep are sheepish!

how do stoats hypnotize rabbits?

Stoats are one of the animal kingdom’s most extraordinary predators. They eat a varied diet, including birds, eggs, insects, and small mammals. They even hunt rabbits, although rabbits are much bigger than stoats and can weigh ten times as much. Rabbits are also strong, alert, agile, and very fast, which makes them an extremely difficult meal to catch. However, stoats have an amazing technique to circumvent all these problems, without even having to chase the rabbit. Instead, they hypnotize it.

The stoat does this by stealthily approaching the rabbit, creeping toward it through the long grass. When it gets within range, it deliberately draws attention to itself, dancing, jumping, and chasing its tail. It’s a bizarre performance. The stoat somersaults, then backflips. It vanishes into the grass, then leaps up in the air again. The rabbit is mesmerized as the dancing stoat gradually gets closer and closer. Suddenly, the stoat leaps toward the rabbit and bites into the back of its neck, smashing the back of its skull with its teeth. The rabbit may twitch once or twice before collapsing, dead. Biting into the rabbit’s skull in this way not only ensures a quick death, but also minimizes the risk that the meat will spoil, since a big rabbit will provide food for days. The businesslike stoat now drags the heavy corpse back to its burrow.

which bird builds a decoy nest?

In the Australian bush, a type of bird called the splendid fairy wren is terrorized by currawongs, which are big, aggressive birds that destroy the fairy wrens’ nests and steal their eggs. The wrens have no way of defending themselves. All they can do is produce a huge number of eggs, in the hope that a few chicks will manage to survive this threat. Luckily, fairy wrens are extremely promiscuous and extremely fertile.

Another bird that lives alongside the fairy wren has a different strategy. Yellow-rumped thornbills are about the same size as fairy wrens and are therefore similarly threatened by the marauding currawongs. Their solution is to build a second, decoy nest, on top of the active one. The decoy nest is simply a cup-shaped depression, while underneath it sits the real nest, with a concealed entrance. Currawongs attack from above, so if they see the empty decoy nest, they are likely to leave it alone and move on without investigating further, unaware of the active nest underneath. Thanks to this clever construction, thornbill nests suffer far less from currawong raids than do their neighbors.

how do squirrels deceive rattlesnakes?

A squirrel’s tail is one of the most versatile tools of any mammal’s. First, squirrels use their tails to balance when walking along a precarious branch. If they do fall, their tail acts as a parachute, catching the air and slowing the squirrel’s descent. When running on the ground, squirrels use their tails as a fifth limb and rudder, to help them change direction at speed. If a bird should attack, a squirrel can shelter under its big bushy tail, making it impossible for the bird to grab it in its talons. In the summer, a tail makes an effective sunshade, while in the winter, it’s a wonderfully soft, warming duvet, which helps the squirrel to conserve precious heat and energy.

Another exciting use for the squirrel’s tail has recently been discovered. Snakes are one of the squirrel’s most dangerous predators, but squirrels have found a way to use their tails to protect themselves against one group, namely the rattlesnake. Rattlesnakes have a poor sense of sight, but they have another way of “seeing” their prey, using their extremely sensitive heat-sensing organs. These organs consist of two small pits, one on either side of the snake’s head, between its eyes and its nostrils. These pits can detect infrared radiation so accurately that the snake can tell the size, shape, distance, and direction of a prey purely from sensing its heat energy, which it can observe at as little as 32.3°F (0.2 degrees Celsius) higher than the surrounding temperature.

When a squirrel is confronted by a rattlesnake, it fills its tail with blood, raising the tail’s temperature. Since the rattlesnake can really see things only if they are warm, this makes the squirrel look twice as big as it otherwise would, which can be enough to make the rattlesnake warily slink off, leaving the squirrel in peace. What is most amazing about this ingenious technique is that squirrels don’t bother to heat up their tails for other snakes. They do it solely for snakes that have these heat-sensing organs.

what is particularly devious about the alcon blue butterfly?

The Alcon Blue butterfly (Maculinea alcon) is an extremely attractive specimen that is found in Europe and northern Asia, where it brightens up many a summer’s afternoon. However, as delicate and charming as they look, Alcon Blues are among nature’s most devious schemers when it comes to raising their young.

The process begins when the butterfly lays its eggs on the leaves of a gentian plant. When the caterpillars hatch from the eggs, they burrow into the gentian buds and feed. During this time, they become much larger, before eventually dropping to the ground. Here, the caterpillar is found by ants. At this point, the caterpillar begins to produce a chemical pheromone, which somehow seems to induce the worker ants to treat it like one of their own precious larvae. The ants take the caterpillar back to their nest and begin to feed it.

Yet the caterpillar is not satisfied with food and safe lodgings. Now its chemical signals instruct the ants to give it preferential treatment. If the nest is disturbed, the ants will rush the caterpillar to safety while ignoring their own young. For an astonishing two years, the ants will continue to feed the interloper until it is fully grown and ready to take its adult form. When it emerges from its pupal stage, the butterfly is at last recognized for the impostor that it is, but by this point the ants’ attacks are futile, since they are unable to grab the butterfly’s adult scales.

This story of deception and intrigue has one more amazing twist. The butterfly does not always make it to its adult stage because another crafty creature may further complicate things. While the Alcon Blue is still a caterpillar, a female ichneumon wasp may appear. This parasitic wasp seems to be able to sense when an ants’ nest is hosting an Alcon Blue. The wasp enters the nest, while the ants panic and try to attack her. In response, the wasp emits a powerful pheromone of her own, which not only repels the ants from her but also makes them attack one another. In the confusion, she lands on the caterpillar and injects an egg deep inside its body.

After the wasp flies off, the ants continue life as normal. They feed the caterpillar as assiduously as always, and it eventually turns into a chrysalis. When the chrysalis opens, it’s not an Alcon Blue butterfly that emerges, but an ichneumon wasp, which has devoured the butterfly pupa from the inside out!

why do male cuttlefish pretend to be female?

Despite their name, cuttlefish are not actually fish. Instead, they are mollusks, from the same class as squid and octopuses. And just like squid and octopuses, cuttlefish are masters of disguise, able to change their shape, color, and texture to evade predators or to sneak up on prey of their own.

They also use these amazing talents in their elaborate courtship displays. Australian giant cuttlefish lead a mostly solitary life, but every winter they come together at Spencer Gulf off the coast of South Australia to mate. There may be as many as eleven males for every female, which means there is considerable competition for partners. Consequently, the cuttlefish use a range of tactics to try to win a mate. Groups of males cluster around a female, jostling for position. The dominant males are those that are biggest and most colorful, so most of the males compete by trying to appear fierce, and by producing striking displays of rippling colors, which travel in waves down their bodies.

The smaller males are unlikely to succeed in this type of competition, so they employ craftier tactics. Sometimes, while the bigger males are fighting for position, a smaller male will appear from behind a rock and sneak in to mate with the female. Naturally enough, he is known as the “sneaker male.”

Some males even pretend to be female themselves, to distract and confuse their rivals. They do this by pulling their arms in and producing mottled colors on their back, which makes them look just like a female cuttlefish. Usually, this will lure some of the males, drawing them away from a real female. At just the right moment, the crafty cross-dresser will then dart back through the pack of males and mate with the real female before his rivals realize that they’ve been fooled.

Cuttlefish are not the only creatures to have discovered the benefits of embracing their feminine side. Young male garter snakes also pretend to be female, to outwit rival males. Garter snakes can’t change color, but the males and females produce pheromones that are distinctive enough to make them instantly distinguishable from one another. Young males also produce female pheromones, and these serve to attract older males, which then attempt to mate with the young impostors. All male garter snakes go through this “cross-dressing” phase in their youth, and it may help them gain an advantage over their older rivals. If the older male is tricked into trying to mate with a young impostor, his chances of being able to mate with a real female will be substantially reduced.

Some birds use a similar strategy, albeit for a slightly different purpose. Male common terns try to attract a female by flying with a fish in their beak, hoping a female will follow. If he manages to tempt a female, the male tern will offer her the fish in midair. The pair then glide together to the ground, where he struts for her benefit, in a courtship display. Some male common terns will pretend to be female and follow their unwitting rival, purely so that they can nab a free dinner.