Brown hyena

Brown hyena Temporal range: Pliocene - Recent
File:Parahyaena brunnea 2.jpg
Conservation status
Vulnerable  (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Carnivora
Family:	Hyaenidae
Genus:	'Hyaena'
Species:	''H. brunnea''
Binomial name
Hyaena brunnea Thunberg, 1820
Geographic range
Synonyms
Parahyena brunnea

The brown hyena (Hyaena brunnea, formerly Parahyaena brunnea) is a species of hyena found in Namibia, Botswana, western and southern Zimbabwe, southern Mozambique and South Africa. It is currently the rarest species of hyena. The largest remaining brown hyena population is located in southern Kalahari Desert and coastal areas in Southwest Africa.

Description

Brown hyenas can measure 86 to 140 cm (34 to 55 in) in head-and-body length, although they average 110 to 125 cm (43 to 49 in). The height at the shoulder is 70 to 80 cm (28 to 31 in) and the tail is 25 to 35 cm (9.8 to 13.8 in) long. Unlike the larger spotted hyena, there are no sizable differences between the sexes, though males may be slightly larger than the females. The average adult male weighs 40.2 to 43.7 kg (89 to 96 lb), while the average female weighs 37.7 to 40.2 kg (83 to 89 lb). The normal upper weight limit for the species is 55 kg (121 lb), although an occasional outsized specimen can weigh up to 67.6 to 72.6 kg (149 to 160 lb). The coat is long and shaggy, particularly on the tail and back. The general fur color is dark brown, while the head is gray, the upper body tawny and the legs grey with dark horizontal stripes. Erectile hairs 305 mm (12 in) in length cover the neck and back. Brown hyenas have powerful jaws: young animals can crack the leg bones of springboks within five minutes of birth, though this ability deteriorates with age as their teeth gradually wear. The skulls of brown hyenas are larger than those of the more northern striped hyenas, and their dentition is more robust, indicating less generalised dietary adaptations. Brown hyenas possess an anal gland below the base of the tail, which produces a black and white paste. The gland has a groove, coated with a white secretion, which divides a pair of lobes which produce a black secretion. These secretions are deposited on grass stalks roughly every quarter mile of their feeding grounds, particularly around territorial borders.

Behavior

Social behavior

Brown hyenas have social hierarchy comparable to those of wolves, with an alpha male and alpha female. They are social animals that may live in clans consisting of one adult of each gender and associated young, though there are reports of clans composed of four males and six females. It is thought that in the latter situation, there is at least one dominant male. Brown hyenas maintain a stable clan hierarchy through ritualized aggressive displays and mock fights. They typically forage alone, and do not maintain a territory, instead using common hunting paths. Emigration is common in brown hyena clans, particularly among young males, which will join other groups upon reaching adulthood.

Reproduction

Female brown hyenas are polyestrous and typically produce their first litter when they are two years old. They mate primarily from May to August, the gestation period lasting 97 days. Unlike aardwolves, female brown hyenas mate with nomadic males or the dominant male member of their own clan. Clan males display no resistance, and will assist the females in raising their cubs. Females give birth in dens, which are hidden in remote sand dunes far from the territories of spotted hyenas and lions. Mothers generally produce one litter every 20 months. Usually, only the dominant female breeds, but if two litters are born in the same clan, the mothers will nurse each other's cubs, though favoring their own. Litters usually consist of 1-5 cubs, which weigh 1 kg (2.2 lbs) at birth. Unlike spotted hyenas, brown hyenas are born with their eyes closed, and open them after eight days. Cubs leave their dens after four months. Also unlike spotted hyenas, all adult members of the clan will carry food back to the cubs. They are not fully weaned and do not leave the vicinity of their den until they reach 14 months of age.

Dietary habits

Brown hyenas are primarily scavengers, the bulk of their diet consisting of carcasses killed by larger predators, though they may supplement their diet with rodents, insects, eggs, fruit and fungi (the desert truffle Kalaharituber pfeilii). However, brown hyenas are aggressive scavengers, frequently appropriating the kills of black-backed jackals, cheetahs, and leopards, including adult male leopards. Single brown hyenas will charge leopards at kills with jaws held wide open and have treed adult male leopards; sometimes, brown hyenas have been observed treeing leopards even when no kill was in contention. In the Kalahari desert, brown hyenas are often the dominant mammalian carnivores present because of their dominance over the other predators listed above, and because of the scarcity of lions, spotted hyenas, and packs of African wild dogs. In areas where they may overlap, Brown hyenas may rarely be killed by spotted hyenas and lions.

Brown hyenas will cache excess food in shrubs or holes and recover it within 24 hours. Brown hyenas are poor hunters, and live prey makes up only a small proportion of their diet: in the southern Kalahari, species such as springhare, springbok lambs, bat-eared foxes and korhaan species make up only 4.2% of their overall diet, while on the Namib coast, cape fur seal pups compose 2.9% of the brown hyenas dietary intake. In the Kalahari, brown hyenas are active 80% of the time at night searching for food in an area spanning 31.1 km (19.3 mi), with 54.4 km (33.8 mi) being recorded. Their powerful sense of smell allows them to track even old carcasses 2 km (1.2 mi) downwind.

Threats and Conservation Status

The global population is estimated to be less than 10,000 individuals.

External links

Template:Commons

• IUCN Hyaenidae Specialist Group Brown Hyena pages
• The Brown Hyena Research Project
• Fossils of the Brown Hyena
• Brown Hyena Images and Video - ARKive.org