Scientific name: Anguis fragilis
Conservation status: Protected in the UK under the Wildlife and Countryside Act, 1981.
Priority Species under the UK Post-2010 Biodiversity Framework.
Slow worms are one of the most common reptiles in London, but they are often overlooked. Perfectly adapted to life in the city, they can be found in various habitats, from parks, gardens and allotments to railway embankments and wasteland.
Firstly, they are not actually worms at all; they are legless lizards. They exhibit the lizard characteristics of being able to blink their eyelids and shed, then re-grow, their tails.
They are relatively small, growing to a length between 40-50cm with a smooth, golden-grey skin. The males are paler and sometimes have blue spots, while the females are larger, with dark sides and a dark stripe down the back. Amazingly they can live for up to 20 years.
Slow Worms like humid conditions and emerge from their hiding places at dusk or after rain to hunt for food. Like other reptiles, they hibernate, spending the winter from October onwards hibernating under piles of leaves, burrowed underground or within tree roots, emerging in March.
In May, mating begins and can be quite an aggressive affair with the male taking hold of the female by biting her head or neck, then they intertwine their bodies. Courtship may last for as long as 10 hours! Females incubate the eggs internally, “giving birth” to an average of eight young in summer.
Gardeners love that they are active hunters, preying on Slugs, Snails, Spiders, insects and Earthworms. As an important part of the urban ecosystem, they help to control populations of insects and also provide food for other animals, such as Hedgehogs, Badgers, Foxes, Magpies and lots of other birds.
One of the biggest threats to Slow Worms is habitat loss, which is why Costons Lane Nature Reserve is an essential safe haven for them. Other threats include pollution, road traffic, and predation by cats.
To avoid predation, they have several natural defence mechanisms. Sometimes they will freeze and “play dead” or flee as they can move remarkably fast despite their name. If they can’t escape, they will deter a predator with their very foul-smelling poo!
As a final resort, they can shed the end of their tail which continues to move around, acting as a distraction so they can escape. The tail does regrow, but not to its full length and cannot be detached again. So if you are approaching these appealing creatures do so carefully to avoid putting them under stress.
This species focus was written by EWGs Assistant Secretary and Newsletter Editor, Sarah Murphy.