“If you look carefully, you can see that some of them have carefully cropped lawns outside,” said Nabil Abbas. “They’re condominiums for water voles.”
For anyone lamenting the dramatic decline of one of the nation’s favourite animals, Redmires conduit is a revelation. The water vole (or water rat) was popularised 110 years ago as ‘Ratty’ from Wind in the Willows, and until recent years was a common sight on English riverbanks.
The conduit’s far bank is dotted with water vole burrows, and if you approach from downwind, the short-sighted voles will let you watch them cheerfully nibbling grass and reeds only yards away.
But please keep your dog on a lead, pleaded Nabil from Sheffield and Rotherham Wildlife Trust (SRWT), and Angus Hunter, Sheffield Council’s biodiversity officer.
“You could see some people from dog walking companies with up to twelve dogs off their leads running through the water, out of control,” said Angus. “And if you remind people their dogs should be on leads, they say: ‘Oh, he loves the little rats in there.’”
Although dogs rarely catch them, water voles find it impossible to feed while hiding from Fido and friends snuffling about in the riverbank. The reduced eating time can be critical when the young voles are growing, said Nabil.
Twenty years ago water voles could be easily seen around Sheffield, on the canal, the river Don, around Woodhouse, and near Abbeydale Industrial Hamlet and Forge Dam. Now the only significant populations are at Redmires and Burbage, along with a new set of sightings around Strines reservoir, he added.
The new Sheffield Lakeland Partnership led by SRWT will investigate water vole numbers around the reservoirs of northern Sheffield, and potentially do further work to improve their habitats and protect any existing colonies.
“The water vole is our giant panda, in terms of being one of the most threatened species we have in the UK,” Nabil said. “These sites where the water voles remain are extremely precious, and being disturbed by dogs reduces their life chances, so if you’re a dog owner, please keep it on a lead and don’t let it go into the water.”
A key reason for the animal’s decline is the spread of the American mink, said Angus. After escaping from the many fur farms across Yorkshire, amphibious mink began to prey on water voles, who had no strategy to escape their transatlantic foe – water voles evade British predators like owls and foxes by diving under water, but mink can happily pull water voles out of their underwater burrows.
Mass mink releases by animal rights activists accelerated the problem, and when the mink fur market declined, some owners just opened their farm gates to cut their losses.
It’s not clear why the mink hasn’t spread to the high moors around Sheffield, but although SRWT campaign against inhumane trapping methods, it’s possible that trapping on grouse moors might reduce American mink numbers in the uplands, said Trust researcher George Lee-Harris from Sheffield Hallam University, who’s been monitoring vole numbers at Redmires.
Earlier this summer, landowners Yorkshire Water installed a 700 metre fence along the Redmires conduit to protect the vole condominiums from disturbance by dogs. George has been counting water vole burrows and ‘latrines’, along with their characteristic 45 degree gnawing signs on reeds. It looks like the voles are doing well behind the fence compared with the unfenced area further out onto the moors.
Yorkshire Water ecologist Ben Aston said the company aim for a ‘net gain for biodiversity’ in the work they carry out. “It’s the right thing to do, and for me it’s great to see so many water voles at Redmires conduit. It really is a refuge for them up there.”
The company aim to carry out further work with the council and SRWT around Redmires in the next few years to improve water vole habitats, and possibly install more protective fencing for a new set of lakeside apartments.
“We’re desperately trying to stabilise the water vole population we have,” said Angus Hunter, “because as it stands we’ve nearly lost them in Sheffield.”