Hazel dormice becoming endangered in UK amid 70% decline, study says

A volunteer checks a hazel dormouse during the release of 20 breeding pairs or trios into woodland in Warwickshire. Photograph: Ben Birchall/PA

Populations of the hazel dormouse, perhaps the most elusive native British mammal, have plummeted by 70% this century.

The nocturnal, tree-dwelling animals are now extinct in 20 counties in England and the species must be reclassified as “endangered” on the International Union for Conservation of Nature red list, according to a study by the People’s Trust for Endangered Species (PTES).