The noctule is Britain largest bat, hunting high and fast over open country and woodland, and its welfare depends on the availability of veteran trees with natural roost cavities that are being progressively lost from the landscape.
Noctule welfare depends on veteran trees with natural cavities that develop over decades of growth. Development pressure, disease, and safety concerns frequently lead to felling of old trees before they develop the cavities that noctules require. The loss of mature oak, ash, beech, and poplar from the landscape eliminates roost sites with no short-term replacement. Bat boxes provide partial compensation but lack the thermal stability and microclimate quality of natural tree cavities.