Under a small, sun-baked mat, a curled metallic-gold slow worm lies basking in the heat, the dark stripe running down its body revealing its youth. Sensing attention, it begins to wriggle away, revealing a companion, which speeds rapidly into the grasses in the opposite direction.
After a winter of social distancing, slow worms – a type of legless lizard that grows up to half a metre long and is often mistaken for a snake – have been venturing out of hibernation to enjoy warming their cold-blooded bodies in the spring sun.
Picnics may be out for now, but an assortment of rugs and mats placed around Sutton Ecology Centre, a secluded two-hectare nature reserve tucked away behind a main road in Carshalton, south London, are playing host to a more subterranean kind of socialising.
The amorous slow worms, which come in an array of polished silvers, golds and browns depending on age and gender, mate for up to 10 hours at a time in May; there’s a good chance that peeling back the corner of one of the mats in the centre during peak season will reveal two entwined.
“It is always a treat to find one,” says Barbara O’Keeffe, a retired local resident who has volunteered at the site for eight years. “When you gently pull back one of the mats to look, for a second you think there’s nothing there, then there’s a glint of gold.”
Though they are rarely seen out in the open, slow worms are common throughout the UK. But the ecology centre – which packs in woodlands, wildflower meadows, and a pond currently teeming with tadpoles and wildfowl chicks – is a hotspot.
“It is positioned at the point where the chalky North Downs meets London clay, in an area fed by one of only about 200 chalk streams in the world,” says David Warburton, senior biodiversity officer for the London Borough of Sutton, which owns the centre. “The site is ideal for reptiles such as slow worms. We have a really healthy population of them, but they are isolated by surrounding roads and housing.”
The reptiles – which live for up to 30 years (the oldest on record was a captive 54-year-old male in Copenhagen zoo) – feast on slugs, snails and insects. In turn they provide food for various birds, as well as badgers and hedgehogs – numbers of which have declined dramatically in the past two decades.
Like all six of the UK’s reptile species, slow worms are protected by the Wildlife and Countryside Act, making it illegal to intentionally kill, injure or sell them. But this doesn’t stop them regularly falling victim to carelessly wielded shovels, a risk that could increase as lockdown increases the amount of time people spend in their gardens during the slow worm mating season.
“Just be mindful that they’re around,” says Warburton. “They are not at all dangerous. If you find one, be careful not to spook it, or it could shed its tail – which is their main defence mechanism. But by all means get close and marvel at how great they are, look at their eyelids, ear holes, forked tongue, and then leave them where you found them.” Leaving out covers such as old rugs or corrugated iron in a sunny spot can encourage them into the garden, he says.
O’Keeffe recommends a bit of messiness in the garden to create a more holistic ecosystem: not mowing areas of lawn, leaving piles of logs and leaves, and ensuring gaps under fences to allow hedgehogs and other animals in and out.
“We often have a stall at local events and I remember one lady being delighted, saying ‘Oh, I’ve been feeling guilty about the wild patch at the bottom of my garden … now I’m going to call it my wildlife area.'”
In normal times the ecology centre welcomes 7,000 schoolchildren a year. The species that call the wildlife centre home, not least the population of slow worms, are a big draw. “Lots of kids haven’t got any frame of reference for things … snails, worms, everything’s ‘icky’,” says Warburton.
The loss of half of the world’s wildlife is at the forefront of the centre’s work. “I don’t think that most people have cottoned onto the fact that there is a biodiversity crisis,” says Warburton. “We teach the kiddies so that they care and will do something about it. Activities like building a stick den, picking up a snail – it helps them to not be scared to get their hands dirty. We try to turn their fear into fascination.”
An understanding of natural processes isn’t always better among local adults, according to Warburton, especially in urban areas. He describes the reaction of the public when his team introduced native cattle to the Roundshaw Downs in 2012, a rare chalk grassland three miles south-east, on the site of London’s first international airport in Croydon. They used castrated male Sussex cattle, which are naturally hornless and very placid. “Well, you’d think we’d released lions. Some people were apoplectic. I had to say: ‘This is not Jurassic Park we are creating!'”
He wonders if the current crisis might bring about a shift in people’s interest in their local wildlife, including the mysterious slow worm. “Hopefully they might realise you don’t have to go to a national park to see cool and interesting species. Once you’ve seen them in your garden, the whole world opens up.”