The little forest bat (''Vespadelus vulturnus'') is a species of

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 ...

in the family Vespertilionidae. It is found only in south-eastern

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

, including

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

. It is a tiny bat often weighing less than (males in some areas weigh as little as ). It is sometimes referred to as Australia's smallest mammal, although the Northern or Koopmans Pipistrelle, '' Pipistrellus westralis'', is possibly smaller, weighing on average around . It is the smallest bat in

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

Biology and ecology

The little forest bat is one of the most commonly observed bats in south-eastern Australia, it is found in a variety of habitats including

Eucalypt Eucalypt is a descriptive name for woody plants with capsule fruiting bodies belonging to seven closely related genera (of the tribe Eucalypteae) found across Australasia: ''Eucalyptus'', '' Corymbia'', '' Angophora'', ''Stockwellia'', ''Allosyn ...

woodlands and forests as well as in rural, semi-rural and some urban areas. It is an

insectivore 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 wer ...

and roosts in

tree hollows A tree hollow or tree hole is a semi-enclosed cavity which has naturally formed in the trunk or branch of a tree. They are found mainly in old trees, whether living or not. Hollows form in many species of trees, and are a prominent feature of nat ...

. Females become sexually mature in their first year and males in their second year. It is assumed the males wake from

torpor Torpor is a state of decreased physiological activity in an animal, usually marked by a reduced body temperature and metabolic rate. Torpor enables animals to survive periods of reduced food availability. The term "torpor" can refer to the time ...

and mate with the females during winter. A single pup is born in spring (October–November).

Identification

The little forest bat is very small with pale grey or brownish fur. The tragus is usually white and the skin on the

face The face is the front of an animal's head that features the eyes, nose and mouth, and through which animals express many of their emotions. The face is crucial for human identity, and damage such as scarring or developmental deformities may aff ...

, feet and

forearm The forearm is the region of the upper limb between the elbow and the wrist. The term forearm is used in anatomy to distinguish it from the arm, a word which is most often used to describe the entire appendage of the upper limb, but which in anat ...

is usually pinkish. Adults usually weigh between and the

is usually less than (mean =). The wingspan can range up to and the body length is up to . Females are slightly larger than males. The little forest bat is very similar in appearance and often confused with a number of other bats that it co-occurs with (

sympatric In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter one another. An initially interbreeding population that splits into two or more distinct species sh ...

) including

Vespadelus regulus The southern forest bat (''Vespadelus regulus'') is a vesper bat found in Australia. Taxonomy A species of '' Vespadelus'', of the diverse and common micro-bats, bats assigned as either suborder Yangochiroptera or Microchiroptera. The descrip ...

Vespadelus darlingtoni The large forest bat (''Vespadelus darlingtoni'') is a common vesper bat found in southeast Australia, Tasmania, and Lord Howe Island. Taxonomy The first description was published by G. M. Allen in 1933. The specimen described was obtained by ...

Vespadelus baverstocki The inland forest bat (''Vespadelus baverstocki'') is a vesper bat that occurs in central and arid regions in Australia. They were first described in 1987, published in a review of poorly surveyed microbat populations. A tiny flying mammal, whose ...

, Vespadelus troughtoni, Vespadelus pumilus and

Scotorepens greyii The little broad-nosed bat (''Scotorepens greyii'') (pronounced skoh’-toh-rep’-enz grey’-ee-ee’) translates to "Grey’s darkness creeper". Sometimes called Grey’s broad-nosed after the third governor of South Australia, Sir John Edward ...

. Live bats can be differentiated from these species using a combination of size, relative finger bone lengths and, in males, penis shape. Males have a distinctly shaped

baculum The baculum (also penis bone, penile bone, or ''os penis'', ''os genitale'' or ''os priapi'') is a bone found in the penis of many placental mammals. It is absent from the human penis, but present in the penises of some primates, such as the ...

. There is some variation in the

morphology Morphology, from the Greek and meaning "study of shape", may refer to: Disciplines *Morphology (archaeology), study of the shapes or forms of artifacts *Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies, ...

of this species across its range, with some taxonomists suggesting there may be

cryptic species In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

that have not yet been identified within the species.

Echolocation call

The echolocation call of the little forest bat is regionally variable, in New South Wales the characteristic frequency of search phase calls is between 42.5 and 53

kilohertz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that one h ...

depending on the region where it is found. This is more than double the maximum frequency of the human

hearing range Hearing range describes the range of frequencies that can be heard by humans or other animals, though it can also refer to the range of levels. The human range is commonly given as 20 to 20,000 Hz, although there is considerable variati ...

and cannot be heard without the assistance of a

bat detector A bat detector is a device used to detect the presence of bats by converting their echolocation ultrasound signals, as they are emitted by the bats, to audible frequencies, usually about 120 Hz to 15 kHz. There are other types ...

References

{{Taxonbar, from=Q305691 Bats of Australia Vespadelus Mammals of Tasmania Mammals of South Australia Mammals of New South Wales Mammals of Victoria (Australia) Mammals described in 1914 Taxa named by Oldfield Thomas Taxonomy articles created by Polbot Vertebrates of Tasmania