Slow-worms are lizards, though they are often mistaken for snakes because they are legless. Unlike snakes they have eyelids, a flat forked tongue and can drop their tail to escape from a predator. They measure about 40 - 45cm, their appearance is always shiny, the males are a greyish brown and the females are brown with dark sides and a thin line down the back. Occasionally, individuals may have blue spots, a feature that is more common amongst males than females.
In juvenile slow worms, the back is iridescent silver, gold, bronze or copper and the sides are brown or black.
Slow worms emerge from hibernation in March, and courtship tends to take place between mid-May and late June. During courtship, a male takes hold of a female by biting her head or neck, and they intertwine their bodies. Courtship may last for as long as 10 hours before copulation occurs.
Most females tend to mate once every two years in Britain; an average of 8 live young are usually born from mid-August to mid-September. The young slow worms are initially encased in the egg membrane, they measure from 70-100 mm in length, and will be fully grown after 6-8 years, becoming sexually mature by 3 or 4 years in males and 4 or 5 years in females.
The Latin name Anguis fragilis means 'fragile snake', and refers to the ability of this lizard to shed its tail when seized; the tail may continue to wriggle after being shed, and can distract predators while the slow worm escapes. A new tail begins to regenerate after a couple of weeks.
Slow-worms rarely bask in the open, instead preferring to hide under logs or in compost heaps. Slow-worms feed on slow-moving prey, particularly small slugs. This species is relatively long-lived; one specimen lived for 54 years. The skin is shed at intervals throughout the life span.
In Britain, slow-worms are protected by law under sub-section 9(1) and all of sub-section 9(5) of the Wildlife and Countryside Act, 1981. This prohibits the intentional killing and injuring and trade (i.e. sale, barter, exchange, transporting for sale and advertising to sell or to buy).
Erik Paterson, CARG Secretary