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 that 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 mammals of the order Chiroptera.''cheir'', "hand" and πτερόν''pteron'', "wing". 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 bi ...

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 familie ...

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 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 (females); late ...

. 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 and western

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...

, eastwards as far as the

Urals The Ural Mountains ( ; rus, Ура́льские го́ры, r=Uralskiye gory, p=ʊˈralʲskʲɪjə ˈɡorɨ; ba, Урал тауҙары) or simply the Urals, are a mountain range that runs approximately from north to south through western ...

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 planet's highest peaks, including the very highest, Mount Everest. Over 100 ...

. It is also found in north-west

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

, the Canary Islands and

Madeira ) , anthem = ( en, "Anthem of the Autonomous Region of Madeira") , song_type = Regional anthem , image_map=EU-Portugal_with_Madeira_circled.svg , map_alt=Location of Madeira , map_caption=Location of Madeira , subdivision_type=Sovereign st ...

. The form in the

Azores ) , motto =( en, "Rather die free than subjected in peace") , anthem= ( en, "Anthem of the Azores") , image_map=Locator_map_of_Azores_in_EU.svg , map_alt=Location of the Azores within the European Union , map_caption=Location of the Azores wi ...

is often considered to be a separate species –

Azores noctule The Azores noctule (''Nyctalus azoreum'') is a species of bat found in the dry forests of the Azores. It is the only species of mammal endemic to the Azores. It has been recorded on most of the islands of the Azores, and remains common on some bu ...

(''Nyctalus azoreum''). It is typically found in

forest A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...

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 ( ; ga, Éire ; Ulster-Scots: ) is an island in the North Atlantic Ocean, in north-western Europe. It is separated from Great Britain to its east by the North Channel, the Irish Sea, and St George's Channel. Ireland is the s ...

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: * The United Kingdom, a sovereign state in Europe comprising the island of Great Britain, the north-eastern part of the island of Ireland and many smaller islands * Great Britain, the largest island in the United King ...

it is known from a few colonies in England and

Wales Wales ( cy, Cymru ) is a country that is part of the United Kingdom. It is bordered by England to the east, the Irish Sea to the north and west, the Celtic Sea to the south west and the Bristol Channel to the south. It had a population in 2 ...

with occasional wanderers reaching

Scotland Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to th ...

. Threats to its survival include declines in large

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of ...

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 paraphyletic group of insects that includes all members of the order Lepidoptera that are not butterflies, with moths making up the vast majority of the order. There are thought to be approximately 160,000 species of moth, many of w ...

s and

beetle Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...

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, street lamp, 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 ...

, 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