Page 28 - ALG Issue 4 2020

biodiversity
Slow Worms
A slow worm (Anguis fragilis) is actually a legless lizard, the only such creature native to Britain, one of three lizard species native to the UK, and the one you’re most likely to encounter in a garden or allotment. Slow worm males are greyish brown and females are brown with dark sides. Slow worms tend to be smaller than the UK’s native snakes. Adults are up to 50 centimetres long. Slow worms blink, have a notched tongue and do not have a pronounced neck region – this is the way that you can tell them apart from a snake.
Slow worms are unique in the UK for being legless lizards, but leglessness is not actually that unusual a trait; it
is associated with elongated bodies and burrowing or living in long grass. This is certainly true of slow worms, which spend much of their time burrowing into loose soil and decaying vegetation. Come October, they tunnel underground to hibernate and remain there until March.
Slow worms are on the menu for many animals, including adders, hedgehogs, badgers, magpies and lots of other birds. They often fall foul of pet cats too. Research shows that slow worms use their tongues to sense the presence
of ambush predators, flicking their tongues in and out to ‘smell’, like snakes. To avoid meeting an untimely end, slow worms employ various
defence mechanisms. Sometimes
they freeze. Other times they will flee. Despite their name, slow worms can move quite quickly. But if they can’t get away, defecation is the first weapon in their arsenal. Their poo smells nasty enough to deter some predators. If pooing doesn’t work, slow worms use another nifty trick to escape predators: they detach their tail. The discarded tail thrashes about for several minutes, distracting their attacker and giving the slow worm the chance to get away. Slow worms are named after this ability - the ‘fragilis’ part of Anguis fragilis means ‘fragile’. Some studies have found that 50-70% of wild slow worms have lost their tails.
Slow worms have a very different diet
to snakes, making a meal of much smaller prey. Slow worms snack on a variety of invertebrates, including slugs, snails, spiders and earthworms. They mate in May and the female gives birth to up to 12 baby slow worms, usually in August or September. Most reptiles lay eggs, but slow worms are ovoviviparous, meaning the eggs hatch while they’re still in the female’s body. She later
gives birth to the hatchlings, which are usually little more than four centimetres long.
Slow worms are quite widespread throughout mainland Britain and most
By DuncanFoto - Own work, CC BY-SA 4.0, https://commons. wikimedia.org/w/index.php?curid=46395166
Bob Pomfret@Pixabay
Slow worms prefer habitats with plenty of dense plant ground cover
common in Wales and southwest England. Slow worms prefer habitats with plenty of dense plant ground cover. They’re often found in woodland glades, pastures, heaths, scrubland, gardens, allotments, railway embankments and road verges. You won’t see any slow worms out and about in winter as they hibernate. Your chances are better from late spring through to early autumn. Slow worms tend to be most active at dusk. This is when they usually hunt for food. During the daytime, rather than basking out in the open, they prefer to hide under something that will heat up in the sun. Anything which retains heat can attract slow worms, like compost heaps and log piles, which they love, because they are also a great source of invertebrates. There is a concern that slow worms are declining due to habitat change and your allotment could be an important refuge – by providing a habitat for slow worms on your plot they will return the favour and eat lots of slugs.
Taken from an article by Lisa Hendry © The Trustees of the Natural History Museum, London. Licensed under the Open Government Licence.
28 Allotment and Leisure Gardener