Lesser Noctule, Nyctalus leisleri

The lesser noctule (Nyctalus leisleri) is a vesper bat that is native to throughout Europe and western Asia, with a range that extends as far as the Himalayas and the Urals. Its range also includes the Canary Islands, northwest Africa, and Madeira. In Azores, it is thought that the populations there are a separate species called Azores Noctule.

It can be found in habitats including coniferous forests, deciduous forests, and occasionally human areas and abandoned buildings. It is considered rare to see within most areas of its range, but in Ireland, it is a common species.

The lesser noctule can reach an average body length between 1.8 to 2.6 inches, with an average weight of .7 ounces. The wingspan is large, reaching 12.9 inches in length. The majority of its fur is dark brown in color with a lighter tip, while the face, wings, and ears are darker. The undersides of the arms are hairy, from which it derives its other common name, the Hairy-armed Bat. The short ears have a mushroom like tragus.

These bats can be found in colonies holding between 20 and 50 individuals, but colonies in Ireland grow to be much larger. Colonies will typically roost within buildings or hollow trees, but occasionally, bat boxes are used. Reproduction results in one through two pups, although it is common in this bat’s eastern range for twins to be born.

The diet of the lesser noctule consists of flying insects, like beetles and moths. It will leave its roost around sunset and fly in erratic dives when hunting. It will fly as far as 6.2 miles while hunting for food, and are active mostly at dawn and dusk.  It is threatened by habitat loss, decreases in large insect populations, and toxic chemicals found within some of the building it roosts within. The lesser noctule appears on the IUCN Red List with a conservation status of “Least Concern”.

Image Caption: Nyctalus leisleri. Credit: Manuel Werner/Wikipedia (CC BY-SA 3.0)