British bats hibernate in winter roosts that require protection from disturbance. Understanding bat welfare during hibernation enables better conservation practice.
Hibernating bats are physiologically vulnerable to disturbance. Rousing from torpor is energetically expensive - each unnecessary arousal can kill a bat that has insufficient fat reserves to survive winter. Bats in buildings, caves and tunnels face disturbance from renovation works, recreational access and agricultural activity. The welfare cost of individual disturbance events is disproportionately high relative to the low disturbance impact on humans. Planning processes that consider bat presence before authorising winter works protect individual welfare and population viability.