Along with serotine bats, noctules are one of the largest British species, and are one of the first to emerge in the evening.

Life span
Maximum recorded age of 12 years.

Statistics
Body length: 6-8.2cm, Wingspan: 32-45cm, Weight: 19-40g.

Physical description
Noctules are one of Britain's largest bats. They have short, golden-brown fur, with a slightly lighter underside. The ears, nose and wing membranes are dark brown and the fur extends on to the wing membrane. The ears are short and stout.

Distribution
They range over most of Europe, except for Ireland and the far north. They are also virtually absent from Spain, Portugal and the south of France.

Habitat
Noctules prefer woodland habitats. The loss of trees with hollows for them to roost in has also led to their decline.

Diet
They emerge early, sometimes before sunset, to feed on moths, beetles and other large flying insects. They fly fast and high above the ground.

Behaviour
From October to April, noctules hibernate in trees, bat boxes, buildings and rock fissures. The sometimes sit on top of each other to keep warm, and in particularly cold winters up to 50 per cent can freeze to death in inadequate hibernacula. In the summer, they roost in tree holes and occasionally, buildings. Noctules are migratory in mainland Europe, although movements across Britain have not been recorded.

Reproduction
The mating season is from August to October. Males defend mating roosts (usually a tree hole) for several weeks, and attract a harem of 4-5 females, who stay for a couple of days. Females move to nursery roosts in May, and give birth in July. In Britain, one young is typical, but in Central Europe, they usually have two young. The young are able to fly after 4 weeks, but do not become independent until they are 5-7 weeks old.

Conservation status
Noctules are not listed on the IUCN list of threatened species. Changes in agriculture have led to the loss of suitable feeding sites, such as hedgerows, woodland edge and pasture.