Dormice ‘thrive’ at National Trust site

Hazel dormice are holding steady and spreading into new areas at the National Trust’s Killerton estate in Devon, despite steep declines across the UK. Rangers say habitat work, including planting hedges and trees and maintaining connected, food-rich woodland, is helping the animals thrive.

Killerton has 100 nest boxes, with rangers weighing and recording dormice from April to October; monitoring since 2018 suggests the local population is stable. Nationally, numbers have fallen by more than two thirds since 2000, largely because habitats have become fragmented. Dormice typically weigh 20g to 40g and begin hibernating as temperatures fall below about 10C.