Hill's sheath-tailed bat (''Taphozous hilli'') is a

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 ...

of the family

Emballonuridae Emballonuridae is a family of microbats, many of which are referred to as sac-winged or sheath-tailed bats. They are widely distributed in tropical and subtropical regions around the world. The earliest fossil records are from the Eocene. Descr ...

. They are found in the deserts of central

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 ...

Taxonomy

The description of the species was published by

Darrell Kitchener Darrell John Kitchener (born 1943) is a biologist who has been active in mammalian research in Western Australia and Indonesia. He is the author of over one hundred papers, published while employed as the senior research biologist at the Western ...

in 1980, reclassifying bats that were presumed to be the more common species ''

Taphozous georgianus The common sheathtail bat (''Taphozous georgianus''), is a bat in the family Emballonuridae, occurring in northern Australia. Taxonomy A description of the species was first published in 1915 by Oldfield Thomas, his notes on two bat genera res ...

''. They are currently assigned as genus ''

Taphozous ''Taphozous'' is a genus of the family Emballonuridae. The wide distribution of the genus includes several regions of Australia, Indonesia, Papua New Guinea and Africa. ''Taphozous'' comes from the Greek τάφος, meaning "a tomb". The common n ...

'', allied with the sheathtail family

. The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

, a female skull and skin, was collected at a mine site, Marandoo, near Mount Bruce in the Hamersley Range National Park ( Karijini NP).Museum specimen id: WAM M 18260 The type specimen was captured with a mistnet while fleeing disturbance at the roof of an

adit An adit (from Latin ''aditus'', entrance) is an entrance to an underground mine which is horizontal or nearly horizontal, by which the mine can be entered, drained of water, ventilated, and minerals extracted at the lowest convenient level. Adits ...

, located within the Marangaroo mine site. The collectors, A. Baynes and C. G. Dawe, obtained the specimen at 4:30 in the afternoon on 7 August 1979. The author of the species named it for the mammologist

John Edwards Hill John Edwards Hill (11 June 1928 – 6 May 1997) was a British mammalogist who described 24 species and 26 subspecies during his career. Early life and education Hill was born on 11 June 1928 in the small hamlet of Colemans Hatch in East Sussex, ...

of the

British Museum The British Museum is a public museum dedicated to human history, art and culture located in the Bloomsbury area of London. Its permanent collection of eight million works is among the largest and most comprehensive in existence. It docum ...

, who had assisted Kitchener and previously worked on the taxonomy of Australian chiropterans. Other common names for the species include Hill's tomb bat, and a variant as Hill's sheathtail bat.

Description

A bat of small size, superficially resembling species ''

''. The colour of the fur is dark brown at the back, becoming slightly lighter at the rump, the wing membranes are greyish brown. The fur over the belly is tipped with olive-brown and has an orange hue. Measurements for the forearms range from 63 to 72 millimetres in length, a mean size of 67.7 mm given for the radius (Kitchener, 1980). The weight range of 20 to 29 grams is averaged to 25.5 g for this species. The length of the head and body combined is 65 to 81 mm, and from the notch at base to tip of ear is 18 to 24 mm. The radial-metacarpal pouch on the wing, a small structure at the wrist, found in some similar species, is present in ''T. hilli''. The male has a

gular pouch Gular skin (throat skin), in ornithology, is an area of featherless skin on birds that joins the lower mandible of the beak (or ''bill'') to the bird's neck. Other vertebrate taxa may have a comparable anatomical structure that is referred to as e ...

at the throat, which is evident yet undeveloped in the female, and this distinguishes the species from the more common population of species ''Taphozous georgianus''. These throat pouches contain gland structures.

Distribution and habitat

An endemic species of

, the distribution range extends from the arid northwest through the central deserts of the Northern Territory and to the northwest corner of South Australia. They occupy fissures at escarpments and cave habitats in arid regions of the centre and west of the continent. The bat has a preference for deeply cleft rock at cliffs near waterholes. As with roosts at mine sites, they are found residing with ''T. georgianus''.

Ecology

''Taphozous hilli'' occurs in the west and centre of the continent in semi-arid regions, it is a specialist in desert environs. They are recorded in the western Murchison and

Pilbara The Pilbara () is a large, dry, thinly populated region in the north of Western Australia. It is known for its Aboriginal peoples; its ancient landscapes; the red earth; and its vast mineral deposits, in particular iron ore. It is also a glo ...

regions, in the

Gibson Desert The Gibson Desert is a large desert in Western Australia, largely in an almost "pristine" state. It is about in size, making it the fifth largest desert in Australia, after the Great Victoria, Great Sandy, Tanami and Simpson deserts. The ...

, and toward

Tennant Creek Tennant Creek ( wrm, Jurnkkurakurr) is town located in the Northern Territory of Australia. It is the seventh largest town in the Northern Territory, and is located on the Stuart Highway, just south of the intersection with the western termin ...

in the east. It is assumed to be common and the number of available roosting sites increased by mining operations. They will occupy a mine site shortly after human presence ceases and congregate with the common sheath-tailed bat ''

''. The composition of the diet is poorly known, other than it feeds on insects. The mouth parts involved in

mastication Chewing or mastication is the process by which food is crushed and ground by teeth. It is the first step of digestion, and it increases the surface area of foods to allow a more efficient break down by enzymes. During the mastication process, th ...

differ to those of their cohabitants, suggesting their chewing process and therefore diet differs from ''T. georgianus''. A single young bat is born and reared during the summer and autumn. The male's distinctive neck pouch enlarges in the breeding season, correlating to activity in the glandular and seminal apparatus, and increases in its depth; the purpose of this gular pouch is unknown but assumed to have a social function. The conservation status in the states of Australia are 'least concern' in Queensland and the Northern Territory, and listed as rare and 'near threatened' in South Australia. Threats are noted as the loss of roost sites and habitat through destruction or dilapidation of the local ecology caused by mining operations and alterations to land use such as

pastoralism Pastoralism is a form of animal husbandry where domesticated animals (known as "livestock") are released onto large vegetated outdoor lands (pastures) for grazing, historically by nomadic people who moved around with their herds. The animal ...

and agriculture. The species is recorded at listed conservation areas. The

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...

(2008) gives the status of least concern, noting there is no evidence of decline and the population is stable.

References

External links

Image of the type specimen's skull
{{Taxonbar, from=Q1830340 Bats of Australia Mammals of South Australia Mammals of Western Australia Mammals of the Northern Territory Taphozous Mammals described in 1980 Taxa named by Darrell Kitchener Taxonomy articles created by Polbot