Slow Worms

Slow worms are common at Rannoch. They are often mistaken for snakes but they are actually legless lizards and the remnants of their legs can be seem on the skeleton. Slow worms are not venomous and are harmless to humans.

Like other lizard the slow worm can shed its tail when it is attacked by a predator. The idea is that the thrashing tail distracts the predator and the slow worm can get away. The tail will regrow but it never gets to be as big as it was originally. Domestic cats are major predators of slow worms and if you have a cat you are unlikely to have slow worms in your garden as slow worms have no defence against cats.

Slow worms are grey or brownish in colour. They may mate for up to 10 hours and the eggs are retained in the female’s body before the live birth. This is called being ovoviviparous. In winter slow worms hibernate in leaves or other deep vegetation. They feed on slugs, snails and worms. Slow worms can live up to 30 years in the wild.

They are cold blooded (poikilothermic) and will warm themselves up by basking in the sun. At other times they are semi-burrowing (semi-fossorial) and stay out of sight under stones or in dense vegetation. On the top of Craigour hill at Pitlochry the National Trust for Scotland has constructed a ‘Hibernaculum’ / ‘refugium’ for reptiles including slow worms. Essentially it consists of a sheet of corrugated iron that warms up in the sun and the reptiles like to crawl beneath it for warmth and protection.

Whilst at the excellent tea room in Glen Lyon I was surprised to see a large slow worm (about a foot long) cross the road.

Rannoch gardeners frequently come across slow worms under stones.

Slow worms are not native to Ireland but were illegally introduced to the Burren area of county Clare in the 1970s.

Creative Commons - credit Bernard Dupont