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How to report a reptile that you find

The slow worm is a legless lizard.  It is generally bronze in colour with a very dark underside.  Some blue scales may be present also, in older males.  This is not necessarily evidence of blue pigment: many types of lizards have blue areas which are actually free of pigment, like the sky, and peoples’ blue eyes.  This is explained in the page on Rayleigh scattering of light, which is inversely proportional to the fourth power of the frequency.  So a slow-worm’s blue is probably caused by loss of pigment, like the greying of human hair.

Young slow worms are like beautiful little copies of the adults, but they have a dark line down the silvery back.

The slow worm is very smooth compared with the adder and the grass snake.  Its head is no wider than its body.  It should be handled with great care, if at all, because it can shed its tail in order to escape.  Many other lizards can do this.  A sort of new tail may grow, but it will never be the equal of the original.  The slow worm is harmless to people, but not to small slugs and insects, and it may benefit your garden.  Sometimes they are happy to live in old brick or stone walls in a garden in a town.

Comparing these pictures with those of the adder shows a difference in the flexibility of the body.  An adder can bend its body tightly so that the two parts lie alongside each other right into the bend.  A slow-worm cannot do that – the third and fourth pictures show that the body  can form an arc of a circle, but it cannot fold its body sharply.

This picture shows how tightly adders can fold their bodies.  In this example a male and a female are staying close together.  If you handle a slow worm you can feel the difference between it and a small snake.  A slow worm can grip surprisingly strongly, for its size.

So adders do not make circles, except by accident – though of course almost any shape is possible.  The shapes they make are probably close to the ones that minimise the bending energy throughout the body, while allowing the snake to go where it wants.

On a smooth hard surface, such as a shiny tarmac road, or on a very powdery track, a snake or a slow-worm may become trapped because it cannot get a purchase.  By putting a stick where the animal can push, the animal can make progress.  This action can be repeated until safety is reached.  A slow-worm, or a grass snake, of course, can be picked up carefully and moved to a better place.  An adder should only be picked up by a knowledgeable person who has a good reason to do so.  Take care, in picking up a slow-worm, to avoid grasping the tail, which can be dropped off, as a means of deflecting attention while the lizard escapes.  This is called autotomy.  This ability is one of the attributes of lizards, like eyelids that can blink, that no snake has.

Many slow worms have a blunt tail, where autotomy has occurred.  They cannot grow a proper new tail.

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