Nest boxes of endangered hazel dormice have been vandalised in the Warwickshire location where they were released earlier this year.
Warwickshire Wildlife Trust staff discovered the nest boxes had been taken down from trees and emptied.
The hazel dormouse is endangered, and to try and help them survive in Warwickshire, their location has not been revealed by the trust.
Some of the boxes had hazel dormouse nests inside but no dormice so the trust is concerned over what has happened to these wild animals.
The crime has been reported to Warwickshire Police, who are now appealing for information about the incident. If members of the public have any information which could help they should contact Warwickshire Police on 101 with the crime number 23-38819-18.
Warwickshire Wildlife Trust’s team of volunteers and staff have worked hard to re-introduce these endangered mammals back to woodlands in Warwickshire.
Pairs of rare hazel dormice were released in June and have been carefully monitored and extra food supplied to ensure their successful introduction.
These cute animals are already extinct in some areas, despite having once been widespread throughout much of Britain. Reintroductions are proving successful with dormice breeding at the new release sites.
Dormice are a protected species in Britain and their breeding sites and resting places are protected by law. It is illegal to deliberately capture, injure or kill hazel dormice or damage or destroy a dormouse resting place or breeding site.
Ian Jelley, director of living landscapes at Warwickshire Wildlife Trust, said: “We were devastated to find that the dormouse nest boxes had been tampered with.
"The project has been a huge success so far, with the re-introduced dormice breeding in the woodland.
"However, this vandalism threatens the future of this species, which is on the brink of extinction in Warwickshire.
"The dormice are legally protected and it is an offence to handle them or interfere with their nests without a license.
"We hope that by raising awareness of what has happened we can stop any further interference with this scheme and give the dormice a fighting chance at survival.”