The Azores noctule (''Nyctalus azoreum'') is a species of

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 ...

found in the dry forests of 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 ...

. It is the only species of mammal

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the Azores. It has been recorded on most of the islands of the Azores, and remains common on some but is rare on others. Its numbers are threatened due to

habitat loss Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

caused by humans, and the remaining populations are quite fragmented. It is known to roost in hollowed-out trees, buildings, and caves. The species is related to the widespread

lesser noctule The lesser noctule, Leisler's bat or the Irish bat (''Nyctalus leisleri''), is a species of insectivorous bat belonging to the vesper bat family, Vespertilionidae. The species was named to honour the naturalist Johann Philipp Achilles Leisler ...

, and in the past was treated as a subspecies of that species. Genetic studies have found that it originated recently from lesser noctules which colonised the Azores, and has low levels of genetic divergence from its parent species. It nevertheless is much smaller than the lesser noctule and weighs less, has darker fur and has a different frequency of echolocation calls (about 4–5 Hz higher), and is usually treated as a separate species. As opposed to other bats, the Azores noctule exhibits an unusually high frequency of diurnal flight, frequently hunting insects by day, although it is still most active at night. It has been hypothesised that the Azores noctules' diurnal foraging behaviour may be due to the absence of

avian Avian may refer to: *Birds or Aves, winged animals *Avian (given name) (russian: Авиа́н, link=no), a male forename Aviation *Avro Avian, a series of light aircraft made by Avro in the 1920s and 1930s *Avian Limited, a hang glider manufacture ...

predators in the Azores. Azores noctules still seem to exhibit some anti-predator behaviour, such as leaving their roosting sites in groups, but this may be related to foraging behaviour or non-avian predators such as rats.

References

{{Taxonbar, from=Q794037 Nyctalus Taxa named by Oldfield Thomas Mammals described in 1901 Mammals of the Azores Endemic fauna of the Azores