The lesser noctule, Leisler's bat or the Irish bat (''Nyctalus leisleri''), is a species of

insectivorous A robber fly eating a hoverfly An insectivore is a carnivorous animal or plant which eats insects. An alternative term is entomophage, which can also refer to the human practice of eating insects. The first vertebrate insectivores we ...

bat Bats are flying mammals of the order Chiroptera (). With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most birds, flying with their very long spread-out ...

belonging to the

vesper bat Vespertilionidae is a family of microbats, of the order Chiroptera, flying, insect-eating mammals variously described as the common, vesper, or simple nosed bats. The vespertilionid family is the most diverse and widely distributed of bat famili ...

family, Vespertilionidae. The species was named to honour the naturalist Johann Philipp Achilles Leisler.

Description

It is a medium-sized bat, slightly smaller than the

common noctule The common noctule (''Nyctalus noctula'') is a species of Insectivore, insectivorous bat common throughout Europe, Asia, and North Africa. Description The common noctule's short fur is dark brown after moulting in June (males) or July/August (f ...

. It has a length of 48 to 68 mm (head and body) and a wingspan of 260 to 330 mm. The forearm measures 38 to 47 mm and the bat's weight is 11 to 20 grams. The face, ears and wings are dark. The fur is brown, darker at the base than the tip unlike that of the common noctule which is the same colour along its length. The undersides of the arms are hairy giving it the alternative name "hairy-armed bat". The ears are short and rounded with a mushroom-shaped tragus. The wings are long and narrow.

Distribution

The lesser noctule is found locally across

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

and western

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

, eastwards as far as the

Urals The Ural Mountains ( ),; , ; , or simply the Urals, are a mountain range in Eurasia that runs north–south mostly through Russia, from the coast of the Arctic Ocean to the river Ural (river), Ural and northwestern Kazakhstan.

and

Himalayas The Himalayas, or Himalaya ( ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the Earth's highest peaks, including the highest, Mount Everest. More than list of h ...

. It is also found in north-west

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

, the

Canary Islands The Canary Islands (; ) or Canaries are an archipelago in the Atlantic Ocean and the southernmost Autonomous communities of Spain, Autonomous Community of Spain. They are located in the northwest of Africa, with the closest point to the cont ...

and

Madeira Madeira ( ; ), officially the Autonomous Region of Madeira (), is an autonomous Regions of Portugal, autonomous region of Portugal. It is an archipelago situated in the North Atlantic Ocean, in the region of Macaronesia, just under north of ...

. The form in the

Azores The Azores ( , , ; , ), officially the Autonomous Region of the Azores (), is one of the two autonomous regions of Portugal (along with Madeira). It is an archipelago composed of nine volcanic islands in the Macaronesia region of the North Atl ...

is often considered to be a separate species – Azores noctule (''Nyctalus azoreum''). It is typically found in

forest A forest is an ecosystem characterized by a dense ecological community, community of trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, ...

s, both coniferous and deciduous, but has also adapted to parkland and urban areas and frequently roosts in buildings. In most parts of its range the lesser noctule is rare, however in

Ireland Ireland (, ; ; Ulster Scots dialect, Ulster-Scots: ) is an island in the North Atlantic Ocean, in Northwestern Europe. Geopolitically, the island is divided between the Republic of Ireland (officially Names of the Irish state, named Irelan ...

it is much more common, being the island’s largest and third most common bat species. Due to the lesser noctule's ubiquity in Ireland, the island is also considered its global stronghold. In

Britain Britain most often refers to: * Great Britain, a large island comprising the countries of England, Scotland and Wales * The United Kingdom of Great Britain and Northern Ireland, a sovereign state in Europe comprising Great Britain and the north-eas ...

it is known from a few colonies in

England England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...

and

Wales Wales ( ) is a Countries of the United Kingdom, country that is part of the United Kingdom. It is bordered by the Irish Sea to the north and west, England to the England–Wales border, east, the Bristol Channel to the south, and the Celtic ...

with occasional wanderers reaching

Scotland Scotland is a Countries of the United Kingdom, country that is part of the United Kingdom. It contains nearly one-third of the United Kingdom's land area, consisting of the northern part of the island of Great Britain and more than 790 adjac ...

. Threats to its survival include declines in large

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

s, loss of forest and hollow trees and toxic chemicals found in treated timber in buildings.

Feeding

The bats emerge soon after sunset to feed on flying insects such as

moth Moths are a group of insects that includes all members of the order Lepidoptera that are not Butterfly, butterflies. They were previously classified as suborder Heterocera, but the group is Paraphyly, paraphyletic with respect to butterflies (s ...

s and

beetle Beetles are insects that form the Taxonomic rank, order Coleoptera (), in the superorder Holometabola. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 40 ...

s. They fly straight and fast with shallow dives, often at treetop level. They sometimes feed around

streetlights A street light, light pole, lamp pole, lamppost, streetlamp, light standard, or lamp standard is a raised source of light on the edge of a road or path. Similar lights may be found on a railway platform. When urban electric power distribution b ...

, catching the insects attracted to them. They are most active around dusk and dawn and will travel up to 10 km while

foraging Foraging is searching for wild food resources. It affects an animal's fitness because it plays an important role in an animal's ability to survive and reproduce. Foraging theory is a branch of behavioral ecology that studies the foraging behavi ...

Reproduction

Lesser noctules usually breed in small colonies of around 20 to 50 individuals but in Ireland they can be much larger, with some colonies numbering as many as 1,000 individuals. The colony is usually in a hollow tree or building; bat boxes may sometimes be used. The females give birth to one or two young, with twins being more common in the eastern part of the range.

Echolocation

The frequencies used by this bat species for echolocation lie between 25 and 54 kHz, have most energy at 29 kHz and have an average duration of 8.5 ms.

Cultural references

An image of the bat is one of the security features of the 2020 £20 banknote of the Ulster Bank of Northern Ireland.

References

External links

ARKive
Photographs
Woodland Management For Bats Guide
{{Authority control Nyctalus Mammals described in 1817 Bats of Europe Mammals of Russia Mammals of Central Asia Mammals of Turkey Mammals of Azerbaijan Noctule, Lesser Mammals of Pakistan Mammals of North Africa Fauna of Madeira Mammals of the Canary Islands