Edible Glitter Used to Track Endangered Water Voles in Wales
In an innovative effort to protect Wales’s endangered water voles, conservationists are feeding the elusive animals edible glitter to help track them in the wild.
Once widespread across south Wales, water voles have now vanished from most of the region, surviving only in a few isolated spots, according to the Wildlife Trust. With their numbers critically low and their shy behaviour making them difficult to monitor, conservationists have turned to creative methods—enter glitter.
The Initiative for Nature Conservation Cymru (INCC) has launched a unique tracking experiment involving edible, biodegradable glitter—commonly used in cake decorating. The idea is simple: if the voles eat food laced with glitter, the sparkly substance should pass through their digestive system and appear in their droppings, providing a way to track their presence and movements.
INCC’s chief executive, Rob Parry, said the team worked closely with veterinary experts to ensure the glitter poses no harm to the semi-aquatic rodents.
“It’s something that we’ve done in nature conservation before for other species, for badgers in particular where we use pellets to put in with peanuts, which badgers love,” said Mr Parry.
“So we’ve taken that idea and scaled it down to water vole size, which means using glitter.”
The goal is to determine whether the voles will willingly consume the glitter. If successful, researchers could analyse droppings to trace different family groups and understand how far they travel. Using various glitter colours could further help distinguish between populations.
Though it may sound whimsical, the project is anything but frivolous. Accurately tracking water voles in the wild could help conservationists tailor habitat restoration efforts—for instance, removing invasive conifer trees from wetlands or fencing riverbanks to prevent livestock from disturbing critical vole habitats.
Such measures could make a significant difference in enabling the species to spread naturally and recover in the wild.
“We’ll be able to see the types of territory, the size and where they go in,” said Mr Parry.
“Are they just using the linear features, the ditches, or are they spreading out into the bog and the molinia grassland habitat?
“That will be really crucial for when it comes to planning for our upland habitats.”
To test the approach, the team is first trialling the glitter method on captive-bred water voles, part of a broader Natural Resources Wales (NRW) programme aimed at reintroducing the species.
Richard Davies of NRW, who has successfully bred and released hundreds of water voles, said the animals are fond of apple—used as the vehicle for the glitter.
“They get everything they need from apples, carrots, and some dried rabbit food as well,” he said.
Though not a natural part of their wild diet, apples are a favourite in captivity and a safe delivery method for the experiment.
“Most predators in the UK would quite happily take a water vole. They need to be able to cope with this heavy predation and replace themselves a lot,” he said.
In one early test, a glitter-coated purple apple was placed on straw bedding inside the voles’ enclosure.
Initially untouched, the apple had largely disappeared within an hour.
The real test, however, was whether the glitter would remain visible after passing through the animals’ digestive system.
Just 24 hours later, the team found their answer—a tiny, glittering dropping. It was a breakthrough moment.
“It’s been a perfect storm of bad things that’s happened to water voles in the last few decades,” he said.
“We have drained an awful lot of their wetland habitat, forced them into linear ditches where we find them now, and then the biggest problem is the American mink, an invasive species that was let out and released from pens and they just turned out to be the perfect water vole predators. The water voles don’t stand a chance, really.”
Parry noted that while the survival of water voles is still precarious, experiments like this offer new hope. The animals, typically wary of environmental changes, did not reject the glitter—an encouraging sign.
As conservationists cheered the first sparkling result, they were reminded that sometimes, even small glimmers can lead to big conservation wins.
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