Roberts's flat-headed bat (''Sauromys petrophilus'') is a species of

free-tailed bat The Molossidae, or free-tailed bats, are a family of bats within the order Chiroptera. The Molossidae is the fourth-largest family of bats, containing about 110 species as of 2012. They are generally quite robust, and consist of many strong-fly ...

native to southern Africa. It is the only species in the genus ''Sauromys''. The scientific name translates as "rock loving lizard-mouse", while the common name honours Austin Roberts, who first described the species.

Description

Roberts's flat-headed bat is a moderately sized free-tailed bat, measuring about in total length, including a tail, and a wingspan of . They weigh from . The body is light grey-brown to dark brown, with creamy-white underparts. The ears are oval in shape, and rise from a common point on the head, unlike those of the closely related genus ''

Mormopterus ''Mormopterus'' is a genus of molossid microchiropterans, small flying mammals referred to as free-tailed bats. The genus has been the subject of several revisions, and the diversity of taxa centred on Australia were separated to a new genus '' ...

''. As the common name suggests, the head is unusually flat, without any

sagittal crest A sagittal crest is a ridge of bone running lengthwise along the midline of the top of the skull (at the sagittal suture) of many mammalian and reptilian skulls, among others. The presence of this ridge of bone indicates that there are excepti ...

. The bat can also be distinguished from many other fee-tailed bats by the lack of a scent gland on the throat of males. The wing area has been measured at , with an

aspect ratio The aspect ratio of a geometry, geometric shape is the ratio of its sizes in different dimensions. For example, the aspect ratio of a rectangle is the ratio of its longer side to its shorter side—the ratio of width to height, when the rectangl ...

of 7.6 to 8.3 and a

wing loading In aerodynamics, wing loading is the total weight of an aircraft or flying animal divided by the area of its wing. The stalling speed, takeoff speed and landing speed of an aircraft are partly determined by its wing loading. The faster an airc ...

of about 12 N/m².

Distribution and habitat

Roberts's flat-headed bat is found in southern Africa from far western

Mozambique Mozambique, officially the Republic of Mozambique, is a country located in Southeast Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi and Zambia to the northwest, Zimbabwe to the west, and Eswatini and South Afr ...

and eastern

Zimbabwe file:Zimbabwe, relief map.jpg, upright=1.22, Zimbabwe, relief map Zimbabwe, officially the Republic of Zimbabwe, is a landlocked country in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, Bots ...

, through northern and western

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

and southern

Botswana Botswana, officially the Republic of Botswana, is a landlocked country in Southern Africa. Botswana is topographically flat, with approximately 70 percent of its territory part of the Kalahari Desert. It is bordered by South Africa to the sou ...

, to western

Namibia Namibia, officially the Republic of Namibia, is a country on the west coast of Southern Africa. Its borders include the Atlantic Ocean to the west, Angola and Zambia to the north, Botswana to the east and South Africa to the south; in the no ...

and possibly the south-western corner of

Angola Angola, officially the Republic of Angola, is a country on the west-Central Africa, central coast of Southern Africa. It is the second-largest Portuguese-speaking world, Portuguese-speaking (Lusophone) country in both total area and List of c ...

. Within this region, it inhabits dry

savanna A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) biome and ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach th ...

, Mediterranean-type shrubby vegetation, and rocky areas.

Behaviour and biology

The bats are nocturnal, and are often caught over water, where they feed primarily on

beetle Beetles are insects that form the Taxonomic rank, order Coleoptera (), in the superorder Holometabola. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 40 ...

s, bugs, and

Hymenoptera Hymenoptera is a large order of insects, comprising the sawflies, wasps, bees, and ants. Over 150,000 living species of Hymenoptera have been described, in addition to over 2,000 extinct ones. Many of the species are parasitic. Females typi ...

n insects. To a lesser extent, they also feed on soft-bodied insects, such as

moth Moths are a group of insects that includes all members of the order Lepidoptera that are not Butterfly, butterflies. They were previously classified as suborder Heterocera, but the group is Paraphyly, paraphyletic with respect to butterflies (s ...

flies Flies are insects of the Order (biology), order Diptera, the name being derived from the Ancient Greek, Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwin ...

, and

Neuroptera The insect order (biology), order Neuroptera, or net-winged insects, includes the lacewings, mantidflies, antlions, and their relatives. The order consists of some 6,000 species. Neuroptera is grouped together with the Megaloptera (alderflies, f ...

ns. They use

frequency modulated Frequency modulation (FM) is a signal modulation technique used in electronic communication, originally for transmitting messages with a radio wave. In frequency modulation a carrier wave is varied in its instantaneous frequency in proporti ...

narrow band calls with a frequency that ranges from 27 to 44 kHz. During the day, they roost in rock crevices. Roosts may harbour up to ten bats, which are often clustered together into smaller, tightly packed groups of up to four individuals each. Pregnant females have been observed in November, but nothing further is known of their reproductive biology and life cycle.

References

{{Taxonbar, from=Q137619 Mammals described in 1917 Mammals of Botswana Mammals of Namibia Mammals of South Africa Mammals of Zimbabwe Molossidae Taxonomy articles created by Polbot