The yellow-bellied sheath-tailed bat (''Saccolaimus flaviventris''), also known as the yellow-bellied sheathtail or yellow-bellied pouched bat, is a

microbat Microbats constitute the suborder Microchiroptera within the order Chiroptera ( bats). Bats have long been differentiated into Megachiroptera (megabats) and Microchiroptera, based on their size, the use of echolocation by the Microchiroptera an ...

species 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 ...

found extensively in Australia and less commonly in parts of

Papua New Guinea Papua New Guinea (abbreviated PNG; , ; tpi, Papua Niugini; ho, Papua Niu Gini), officially the Independent State of Papua New Guinea ( tpi, Independen Stet bilong Papua Niugini; ho, Independen Stet bilong Papua Niu Gini), is a country i ...

.Flannery, T. F. 1995. ''The Mammals of New Guinea'', 2nd edition. Reed Books, Sydney, Australia.Churchill, Sue. 2008. ''Australian bats'', 2nd ed. Allen & Unwin, Crows Nest, NSW. Although found throughout most parts of Australia, very little is known about its

ecology Ecology () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overl ...

due to the small size, nocturnal activity, and general elusiveness of most microbat species, making them difficult to study.Rhodes, M. P., and Hall, L. S. 1997. Observations on Yellow-bellied sheath-tailed bats ''Saccoliamus flaviventris'' (Peters, 1867)(Chiroptera: Emballonuridae). Australian Zoologist 30:351-357.Reardon, T. B., and Flavel, S. C. 1987. ''A guide to the bats of South Australia''. South Australian Museum.Richards, G. C. 2008. Yellow-bellied Sheath-tailed Bat, ''Saccolaimus flaviventris''. In: S. Van Dyck and R. Strahan (eds), ''The mammals of Australia''. Third Edition, pp. 472-473. Reed New Holland, Sydney, Australia. They are sometimes mistaken for the endangered and less widely distributed bare-rumped sheathtail bat where the two species occur sympatrically, as well as other similar Emballonuridae species, but upon inspection are quite distinct and easily identifiedSchulz, M. and Thomson, B. 2007. National recovery plan for the bare-rumped sheathtail bat ''Saccolaimus saccolaimus nudicluniatus'' . Report to Department of the Environment and Water Resources, Canberra. Queensland Parks and Wildlife Service, Brisbane. At present, the yellow-bellied sheath-tailed bat is the only member of the Microchiroptera that has been positively identified as a carrier of

Australian bat lyssavirus ''Australian bat lyssavirus'' (''ABLV''), originally named ''Pteropid lyssavirus'' (''PLV''), is a zoonotic virus closely related to the rabies virus. It was first identified in a 5-month-old juvenile black flying fox ('' Pteropus alecto'') col ...

Taxonomy

The first description of the species was provided by

Wilhelm Peters Wilhelm Karl Hartwich (or Hartwig) Peters (22 April 1815 in Koldenbüttel – 20 April 1883) was a German naturalist and explorer. He was assistant to the anatomist Johannes Peter Müller and later became curator of the Berlin Zoological Muse ...

in 1867, using a specimen that

G. R. Waterhouse George Robert Waterhouse (6 March 1810 – 21 January 1888) was an English natural history, naturalist. He was a keeper at the department of geology and later curator of the Zoological Society of London's museum. Early life George was born ...

had proved to

John Gould John Gould (; 14 September 1804 – 3 February 1881) was an English ornithologist. He published a number of monographs on birds, illustrated by plates produced by his wife, Elizabeth Gould, and several other artists, including Edward Lear, ...

. The yellow-bellied sheath-tailed bat belongs to the suborder Microchiroptera, or insectivorous microbats, and is the largest Australian member of the family Emballonuridae. The Emballonuridae are distinguished by a partially membrane-enclosed tail that projects into a sheath, hence the descriptive term sheathtail, and is represented by eight known Australian species. Within Australia, the family is divided into two genera: ''

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 ...

'' and ''

Saccolaimus ''Saccolaimus'' is a genus of the family Emballonuridae, small insectivorous bats with distinctive sheathtails and pouches at the wrist. The species have been placed with genus ''Taphozous'', in subgenus ''Taphozous'', although an elevation to ...

'', the latter of which the yellow-bellied sheath-tailed bat is one of only four known representatives worldwide.Troughton, E. Le G. 1925. A revision of the genera ''Taphozous'' and ''Saccolaimus'' (Chiroptera) in Australia and New Guinea, including a new species, and a note on two Malayan forms. Records of the Australian Museum 14:313-341

Description

The yellow-bellied sheath-tailed bat is quite large with a mean body weight of 44 g that ranges from 28 to 60 g, and a mean head-body length of 81.8 mm that ranges from 72.3-91.9 mm. It has distinct fur colouration, with the dorsal back being a shiny jet black and the ventral underside a contrasting creamy white. Males of the species have a distinctive

gular Gular is of or pertaining to the throat In vertebrate anatomy, the throat is the front part of the neck, internally positioned in front of the vertebrae. It contains the pharynx and larynx. An important section of it is the epiglottis, separatin ...

throat pouch that is believed to play a role in territorial marking.Chimimba, C.T. and Kitchener, D.J. 1987. Breeding in the Australian yellow-bellied sheath-tailed bat, ''Saccolaimus flaviventris'' (Peters, 1867) (Chiroptera Emballonuridae). Records – Western Australian Museum 13:241-248.Hall, L. S. and Gordon. G. 1982. The throat-pouch of the yellow-bellied bat, ''Taphozous flaviventris''. Mammalia 46:247-252 The throat pouch is absent in females, which instead have naked folds of skin around their throats. Unlike many other sheathtails, this species does not have a wing pouch in either sex. Other distinguishing features of the yellow-bellied sheath-tailed bat are a flattened head and sharply pointed muzzle,Yellow-bellied sheath-tailed bat – profile
Office of Environment and Heritage, accessed 7 October 2014 a mean forearm length of 74–77 mm, and a mean outer canine width of 6.4 mm.

Distribution and habitat

The yellow-bellied sheath-tailed bat appears to be wide-ranging, occurring across most parts of eastern and northern Australia,Dickman, C. R., Pressey, R. L., Lim, L., and Parnaby, H. E. 1993. Mammals of particular conservation concern in the Western Division of New South Wales. Biological Conservation 65:219-248. though in what densities remains uncertain due to the difficulties associated with capture and detection of the species. Much of the distribution understanding of this species has developed as a result of incidental sightings,Lumsden, I. F. and Bennet, A. F. 1995. Bats of a semi-arid environment in south-eastern Australia: biogeography, ecology and conservation. Wildlife Research 22:217-239.Pennay, M. n.d. ''Ecological study of the endangered bristle-nosed bat (Mormopterus ‘species 6’) and survey of Microchiropteran bats in Gundabooka National Park - Report for NSW National Parks & Wildlife Service Upper Darling Region''. NSW Department of Environment & Conservation. such as one record from central western Queensland that was taken from a mummified bat found on a barbed-wire fence.Young, R. A. and Ford, G. I. 2000. Bat fauna of a semi-arid environment in central western Queensland, Australia. Wildlife Research 27:203-215. Though most common throughout the

tropical The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

regions of their range, yellow-bellied sheath-tailed bats are known to occur regularly in

semi-arid A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi- ...

environments including the Mallee region of north-western Victoria,

Gundabooka National Park The Gundabooka National Park is a protected national park in the north-west region of New South Wales, in eastern Australia. The national park is located approximately northwest of Sydney. The nearest town is , to the north. The national pa ...

in northwestern New South Wales, and central-western Queensland. This species likely migrates into its southerly range during summer, with seasonal records placing bats in most parts of Victoria, southwestern New South Wales, and the adjacent regions of South Australia. Though less common, two specimens of yellow-bellied sheath-tailed bats have been found in

, one in the National Capital District and the other in Central Province. This species occupies most wooded habitats, including both wet and dry

sclerophyll forest Sclerophyll is a type of vegetation that is adapted to long periods of dryness and heat. The plants feature hard leaves, short internodes (the distance between leaves along the stem) and leaf orientation which is parallel or oblique to direct ...

, mallee and '' Acacia'' shrubland, desert, and open woodland. They are a hollow-roosting species, so tend to be found in proximity of adequate old-growth trees.Hall, L. S. and Richards, G. C. 1979. ''Bats of eastern Australia''. Queensland Museum, Brisbane.

Ecology

Roosting habits

Few studies have been carried out to determine the specific roosting habits of this species. Yellow-bellied sheath-tailed bats are a cavity-roosting species and are generally reliant on old-growth forest hollows. However, they have been known to opportunistically use abandoned animal burrows and human structures, and roost under dry clay and rock, though generally only solitary bats have been observed to do this. Yellow-bellied sheath-tailed bats are mostly solitary, occasionally nesting in small, mixed-sex colonies of two to 10 individuals. A notable exception to this observation is the Brightview colony, found in southeast Queensland in 1996. The colony was discovered by accident during the felling of an old tree, and consisted of 29 individuals – the largest colony of yellow-bellied sheath-tailed bats recorded.

Seasonality

Though no confirmatory studies have been carried out, yellow-bellied sheath-tailed bats may be migratory based on local records that show the species occurring only at specific times of year. Though specific seasonal movements are unknown, observations have suggested migratory movements to the cooler southern Australian ranges during the summer. The possibility of seasonal migration is supported by studies of long, narrow wing shape in the species that appears suited to migration and the seasonal appearance of apparently exhausted bats in Victoria and South Australia.

Diet and foraging

Yellow-bellied sheath-tailed bats are

canopy Canopy may refer to: Plants * Canopy (biology), aboveground portion of plant community or crop (including forests) * Canopy (grape), aboveground portion of grapes Religion and ceremonies * Baldachin or canopy of state, typically placed over an ...

feeders, meaning that they are capable of fast flight, but inefficient at rapid maneuvering. They generally feed at heights of 20–25 m, unless feeding in open spaces or at forest edges, where they forage lower. Studies of stomach contents have found Orthoptera (grasshopper), Coleoptera (beetle), and Hemiptera (true bug) species, with beetles making up the bulk of the diet.Vestjens, W. J. M. and Hall, L. S. 1977. Stomach contents of forty-two species of bats from the Australasian region. Wildlife Research 4:25-35.Coles, R. B. and Lumsden, L. 1993. Report on the survey of bats in the Heathlands area of Cape York Peninsula. Cape York Peninsula Scientific Expedition Wet Season 1992 Report 2:247-259.

Reproduction

Breeding receptivity in the yellow-bellied sheath-tailed bat begins in August when the right

uterine horn The uterine horns (cornua of uterus) are the points in the upper uterus where the fallopian tubes exit to meet the ovaries. They are one of the points of attachment for the round ligament of uterus (the other being the mons pubis). They also provi ...

increases in diameter, achieving maximum size in November. A single offspring is produced between December and March, with mammary glands regressing by the end of May.

Flight

Yellow-bellied sheath-tailed bats have a distinctive flight behaviour characterised by a fast, straight-line flight path with slow wing beats. This distinctive flight pattern combined with the light-coloured fur of the ventral underside make the species easy to identify in flight. The long, narrow wing shape and large body mass of the species allow for rapid flight with low maneuverability, making it best suited to canopy level and open-space flight.

Physiology

The yellow-bellied sheath-tailed bat is a nocturnal species that appears to be most active at least one hour after dark, but only maintains this activity briefly for a few hours. Many Emballonuridae species have been shown to conserve energy through prolonged states of

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 ...

Behaviour and communication

Like all microbats, the yellow-bellied sheath-tailed bat communicates using echolocation, with only some sounds audible to the range of human hearing. Observational recordings have shown specific sequences of sounds to be associated with different behaviours, such as foraging, prey acquisition, and

territoriality In ethology, territory is the sociographical area that an animal consistently defends against conspecific competition (or, occasionally, against animals of other species) using agonistic behaviors or (less commonly) real physical aggression. ...

. This species has been observed engaging in intraspecific aerial displays of aggression.

Conservation

Though infrequently encountered, the conservation status of the yellow-bellied sheath-tailed bat is categorised as of least concern, because the species is both widespread and versatile in its habitat selection, thus is considered unlikely to decline rapidly. Conservation status at the state level is more cautious, most likely due to insufficient population data. In NSW, the species is listed as vulnerable under the Threatened Species Conservation Act 1995, in South Australia as rare under the

National Parks and Wildlife Act 1972 Protected areas of South Australia consists of protected areas located within South Australia and its immediate onshore waters and which are managed by South Australian Government agencies. As of March 2018, South Australia contains 359 sepa ...

,Atlas of Living Australia
Accessed 7 October 2014. and in Victoria as threatened under the provisions of Part 3 of the Victorian Flora and Fauna Guarantee Act 1988.Advisory List of Threatened Vertebrate Fauna in Victoria
2013, The State of Victoria Department of Sustainability and Environment, accessed 7 October 2014 The main threats to conservation of the yellow-bellied sheath-tailed bat are habitat loss, particularly of old-growth trees, disturbance to roosting sites, and prey depletion or secondary poisoning as a result of pesticides and herbicides.