The bat-eared fox (Otocyon megalotis) is a species of fox found on the African savanna. It is the only extant species of the genus Otocyon and considered a basal canid species. Fossil records indicate this canid first appeared during the middle Pleistocene.
It is named for its large ears, which have a role in thermoregulation. The bat referred to in its colloquial name is possibly the Egyptian slit-faced bat (Nycteris thebaica), which is abundant in the region and has very large ears. Although not commonly used, other vernacular names include big-eared fox, black-eared fox, long-eared fox, Delalande's fox, cape fox, and motlosi.
Systematics and evolution
The bat-eared fox is the only living species of the genus Otocyon. Its scientific name, given by Anselme Gaëtan Desmarest, was initially Canis megalotis (due to its close resemblance to jackals), and later changed by Salomon Müller which placed it in its own genus, Otocyon; its huge ears and different dental formula warrant inclusion in a genus distinct from both Canis and true foxes (Vulpes). The generic name Otocyon is derived from the Greek words otus for ear and cyon for dog, while the specific name megalotis comes from the Greek words mega for large and otus for ear.
Due to its different dentition, the bat-eared fox was previously placed in a distinct subfamily of canids, Otocyoninae, as no relationship to any living species of canid could be established. However, according to more recent examinations, this species is regarded as having affinities with the vulpine line, and Otocyon was placed with high confidence as sister to the clade containing both the raccoon dog (Nyctereutes) and true foxes (Vulpes), occupying a basal position within Canidae.
Subspecies
Currently, there are two recognized subspecies: Otocyon megalotis megalotis (Desmarest, 1822) — found in southern Africa Otocyon megalotis virgatus (Cabrera, 1910) — found in eastern Africa
Fossils
Otocyon is poorly represented in the fossil record. It is suggested the genus forms a clade with Prototocyon, an extinct genus of canid. However, the generic distinction between Prototocyon and the extant Otocyon is doubtful. Fossils of an extinct fox-like canine known as Otocyon recki, have been found in sediments of the Olduvai Gorge, Tanzania, dating back to the late Pliocene or early Pleistocene. However, it is now often placed in Prototocyon.
Description
Bat-eared foxes are relatively small canids, ranging in weight from 3 kg to 5.3 kg. Head and body length is 46–66 cm, tail length is 23–34 cm, shoulder height is 30–40 cm, and the notably large ears are 11–13 cm long.
Generally, the pelage is tan-colored, with gray agouti guard hairs, giving its grizzled appearance, appearing more buff on the sides. The undersides and throat are pale. The limbs are dark, shading to dark brown or black at their extremities. The muzzle, the tip and upperside of the tail and the facial mask are black. The insides of the ears are white. Individuals of the East African subspecies, O. m. virgatus, tend toward a buff pelage with dark brown markings, as opposed to the black of O. m. megalotis. Proportionally large ears of bat-eared foxes, a characteristic shared by many other inhabitants of hot, arid climates, help to distribute heat. They also help in locating prey.
Range and distribution
The bat-eared fox has a disjointed range of distribution across the arid and semi-arid regions of Eastern and Southern Africa, in two allopatric populations (representing each of the recognized subspecies) separated by approximately 1,000 km. Subspecies O. m. virgatus extends from southern Sudan, Ethiopia and Somalia, through Uganda and Kenya to southwestern Tanzania; O. m. megalotis occurs in the southern part of Africa, ranging from Angola through Namibia and Botswana to South Africa, and extends as far east as Mozambique and Zimbabwe, spreading into the Cape Peninsula and toward Cape Agulhas. Home ranges vary in size from 0.3 to 3.5 km2. There are no confirmed observations in Zambia.
Habitat
Bat-eared foxes are adapted to arid or semi-arid environments. They are commonly found in short grasslands, as well as the more arid regions of the savannas, along woodland edges, and in open acacia woodlands. They prefer bare ground and areas where grass is kept short by grazing ungulates and tend to hunt in these short grass and low shrub habitats. However, they do venture into areas with tall grasses and thick shrubs to hide when threatened.