It is not difficult to distinguish the main groups of snakes in the field. Differences in coloration, behaviour and habitat all help to make a general identification possible. Precise identification may require the capture of the specimen for detailed scale counts. The main groups can be distinguished by the following general features.
Head blunt, with vestigial eyes; body shiny, and tail short, with a spine at the tip; belly scales not enlarged. Usually plain black or brown in colour, sometimes blotched. Burrow underground; wriggle but never bite.
Head triangular, covered with small scales, and with prominent pits on the lips; body strong and muscular with smooth, small scales; belly scales enlarged; tail moderately long. Usually blotched in brown, cream and olive.
Head triangular, covered with small scales (with the exception of night adders), and usually with a prominent mark (‘V’-shaped or arrow-shaped) on the crown; body fat, with rough small scales; belly scales enlarged; tail very short. Usually blotched in browns and greys. Active in the early morning or evening. Usually give a warning hiss, and strike readily.
Head covered with large, symmetrical scales on crown; belly scales enlarged; large front fangs. Body form, coloration and habits very varied. Except for garter snakes, all threaten by raising the forebody and inflating or spreading the neck.
Head covered with large, symmetrical scales on crown and enlarged belly scales. Body form, coloration and habits are varied.
Lizards cause the most confusion, but they do have family characteristics that allow general identification.
Skinks have smooth, shiny, cylindrical bodies, with narrow, pointed heads, no obvious necks, and tapering tails that can be shed and regrown. They move slowly, searching for food, and when disturbed usually slink behind cover, while keeping a watchful eye. Many burrowing species have short tails, and usually have no limbs, or vestigial limbs.
Lacertids have similar body shapes to skinks, but their body scales are granular and not shiny, and the tail is usually noticeably longer than the body. It is shed easily and regrown quickly. They are mostly terrestrial, ‘sit-and-wait’ predators. When disturbed they sprint rapidly from bush to bush.
Large terrestrial lizards that have shiny, cylindrical bodies. The body scales are rectangular and not rounded. A prominent lateral fold on the side of the body further distinguishes them from skinks. The long tail can be shed, but is regenerated quickly. They move around slowly, searching for food, which is often uncovered by scratching with the forelimbs.
They have flattened bodies, girdled in rings of spiny scales. The head is triangular with a narrow neck and large, symmetrical scales on the crown. The tail is very spiny, and can be shed and regenerated. They bask, head up, on prominent rocks, and retreat into rock cracks or hollows when disturbed.
Very large lizards; even as hatchlings they are bigger than most other lizards. The snake-like tongue is constantly flicked in and out. The crown of the head is covered in small scales. The tail cannot be shed or regrown, and is used as a whip in defence.
Medium-sized lizards with fat, spiny bodies, narrow necks, and well-developed legs. The tail cannot be shed or regrown. Often perch in prominent spots with the head held high. Males are very colourful.
Slow-moving, mainly arboreal species. Their unusual clasping feet, telescopic tongue and protruding eyes that move independently are all unique. The tapering tail cannot be shed or regrown. Males often have complicated crests and horns on the head.
Geckos are mostly nocturnal, although day geckos, like other lizards, are active during the day. All climb on rocks or trees and can leap across small gaps. To aid this they usually have flared toe-tips. When disturbed they hide in rock cracks or behind branches. The head and body scales are small, granular and not shiny. The tail can be shed, but is regrown.
Worm-like, legless, with soft, usually pink-violet skin, with rings of soft, square scales, and vestigial eyes. Wriggle underground.
Crocodiles look superficially like lizards, but have twin keels on the tail, which is squarish in cross-section. In addition, their hindfeet are webbed, and their nostrils and eyes are displaced to the top of the head. All are aquatic and never found far from water.
Tortoises, terrapins and turtles are characterised by their protective shells. They have different habits, and are distinguished by their feet. Tortoises live on land, and have thick, short feet. Terrapins live in fresh water, and have a webbed frill to the hindlimbs. Turtles are marine and the forelimbs are flippers.
Frogs are difficult to place in family groups as many of their key features are internal, and many unrelated species may look superficially similar.