Will glitter save water voles in Wales?

Welsh water voles are being served apples sprinkled with purple glitter for breakfast. This unusual diet is part of a broader project led by Natural Resources Wales (NRW), aiming to save these charming brown rodents from extinction. Now, scientists will be on the lookout for suspiciously sparkling droppings in ditches.

Who wiped out the water voles?

When Kenneth Grahame wrote his beloved children’s novel The Wind in the Willows in the early 20th century, with the Water Rat as one of the main characters, water voles (Arvicola amphibius) were still a common species across the British Isles. Today, the population in all of Wales has shrunk to just 4,500 individuals – a staggering 89 percent decrease since 1995.

These small mammals, resembling rats in appearance – hence the nickname “water rats” – prefer to live along the banks of rivers, lakes, and ponds. Unfortunately, wetland drainage and changes in land use have forced them to move into drainage ditches. There, they encountered a serious threat – the predatory American mink. This rapidly spreading invasive species has relentlessly hunted the voles and driven them to the brink of extinction in Wales.

Rescue mission for the water rats

The governmental body NRW plans to release captive-bred voles into the wild and provide them with proper protection. But for this effort to succeed, scientists need to better understand the habits and territorial range of these very shy and secretive rodents. This is where the glitter comes in.

By monitoring the activity of individual water vole families, NRW will be able to intervene precisely where needed. Conservation measures include removing invasive conifer species from wet habitats and fencing off riverbanks to reduce grazing pressure from sheep.

Water voles need not only soft banks for burrowing but also dense vegetation to provide cover and food. Livestock grazing and interference with watercourses for flood prevention purposes are highly detrimental to them.

Why glitter?

The idea of feeding endangered animals with marked food is not entirely new. The Welsh organization Initiative for Nature Conservation Cymru (INCC), responsible for coordinating water vole monitoring, has previously used colored pellets in food for badgers. Since voles are much smaller, edible glitter – commonly used to decorate cakes – was chosen instead. According to veterinarians, it poses no health risk to the rodents.

The concept is currently being tested in a pilot project on voles under NRW’s care, ahead of their planned reintroduction into the wild. Apples, carrots, and dry rabbit food – all treats commonly used in rodent husbandry – are being dusted with glitter. Even though the animals are naturally timid and react poorly to changes, they don’t seem to mind the decorated food. Just 24 hours after the first glittery meal, the INCC team happily recorded the appearance of sparkling droppings.

Scientists now plan to use different glitter colors to study the territorial range and preferences of individual vole families. “We’ll see whether they stick to drainage ditches or also venture into marshes and grassy habitats with purple moor grass,” says Rob Parry of INCC.

This knowledge could prove invaluable for saving this endangered species, which has been protected across the UK since 1981.

main photo credit: Peter Trimming/Flickr