Hyracoidea

Hyraxes
(Procaviidae)

Class Mammalia

Order Hyracoidea

Family Procaviidae

Number of families 1

Thumbnail description
Hyraxes are small- to medium-sized herbivores, with short legs, a rudimentary tail, and round ears

Size
Head-body length 17–21 in (44–54 cm); weight 4–12 lb (1.8–5.4 kg)

Number of genera, species
3 genera; 5–11 species

Habitat
Forests, woodlands, and rock boulders in vegetation zones from arid to alpine

Conservation status
Vulnerable: 3 species

Distribution
Southwest and northeast Africa, Sinai to Lebanon, and southeast Arabian Peninsula

Evolution and systematics

Hyraxes were probably the most important medium-sized grazing and browsing ungulates in Africa, as investigations on the 40-million-year-old fossil beds in the Fayûm, Egypt, have shown. During this period, there were at least six genera, ranging in size from that of contemporary hyraxes to that of a hippopotamus. During the Miocene (about 25 million years ago [mya]), at the time of the first radiation of the bovids, hyrax diversity was greatly reduced, with species persisting only among rocks and in trees—habitats that were not invaded by bovids.

Fossil and morphological evidence shows that hyraxes share many features with elephants and seacows. Recent research using mitochondrial DNA provides additional support for the association of the paenungulates (elephants, hyraxes, and seacows), which, together with sengis (elephant shrews), aardvarks, tenrecs, and golden moles, are called the Afrotheria, a supraordinal grouping of mammals whose radiation is rooted in Africa.

Contemporary hyraxes retain several primitive features, notably the feeding mechanism, which involves cropping with the molars instead of the incisors as with most modern hoofed mammals, imperfect endothermy, and short legs and feet.

Hyraxes are members of the order Hyracoidea, family Procaviidae. Three living genera contain five species superficially similar in size and appearance. The word hyrax derives from the Greek word hyrak, which means shrew.

The genus Procavia contains two extinct and one living species (Procavia capensis) of Africa and southwest Asia. However, several authors have described four species for this genus: Cape hyrax (P. capensis), Abyssinian hyrax (P. habessinica), Johnston's hyrax (P. johnstoni), and western hyrax (P. ruficeps), while Bothma, in 1966, added a fifth species, the Kaokoveld hyrax (P. welwitschii). More recent studies on the geographic variation in mitochondrial DNA in South Africa indicate that at least two species in what conventionally has been regarded as P. capensis. Therefore, the monospecificity of the genus Procavia

by Olds and Shoshani in 1982 is debatable and only further research on the genetics will provide clarification.

For the bush hyrax, genus Heterohyrax, a single species (H. brucei) and 25 subspecies have been described though some consider H. atineae and H chapini as separate species.

Tree hyraxes in the genus Dendrohyrax include three living species endemic to Africa: western tree hyrax (D. dorsalis), southern tree hyrax (D. arboreus), and eastern tree hyrax (D. validus).

As for rock hyraxes, the species level classification for bush and tree hyraxes is still uncertain; there may be more species than currently accepted. Further research on their anatomy, genetics, behavior, and bioacoustics is necessary.

Physical characteristics

Hyraxes are small- to medium-sized herbivores, with short legs, a rudimentary tail, and round ears. They have a rabbit-like appearance, hence the vernacular name, rock rabbit. Males and females are approximately the same size. The average size of the adult rock hyrax varies greatly across Africa, and it seems to be closely linked to precipitation. The odd appearance of the hyrax has caused some confusion. Their superficial similarity to rodents led Storr, in 1780, to mistakenly link them with guinea pigs of the genus Cavia, and he thus gave them the family name of Procaviidae, or "before the guinea pigs." Later, the mistake was discovered and the group was given the equally misleading name of hyrax, which means "shrew mouse."

The feet have rubbery pads containing numerous sweat glands, and are ill equipped for digging. The feet sweat while the animal is running, which greatly enhances its climbing ability. Bush and tree hyraxes are very are agile climbers and good jumpers; they can ascend a smooth tree trunk up to 20 in (50 cm) in diameter. Feet are flexible and can be turned sole upwards. The forefoot has four digits, while the hindfoot has three. All digits have flat, hoof-like nails, except for the second digit of the hind foot, which has a long, curved claw for grooming.

Species living in arid and warm zones have short fur, but tree hyraxes and species in alpine areas have thick, soft fur. The pelage is dense, with short, thick underfur, and black guard hairs (tactile hairs or vibrissae) up to 1.2 in (30 mm) long are widely distributed over their bodies, probably for orientation in dark fissures and holes. Vibrissae are evident on the snout, above the eyes, under the chin, along the back and sides, on the abdomen, and on fore- and hind limbs.

A dorsal gland lies beneath a raised patch of skin approximately 0.6 in (1.5 cm) long that is surrounded by the dorsal spot of erectile hairs. These hairs are erected during mating behavior, when animals are aroused, and may function as an alarm or threat signal to other hyraxes. The gland in sexually active, mature adults consists of lobules of glandular tissue, is odiferous, and may function in mating and recognition of the mother by young. During courtship, the male erects the hairs of the dorsal spot, exposing the dorsal gland. This probably provides olfactory stimulation and allows dissemination of scent that may communicate the identity and status of the individual. The erectile hairs around the dorsal gland is a light cream to yellow-colored circle of hairs in all species, with the exception of the rock hyrax of southern Africa, in which it is not conspicuous.

Coat color of rock hyrax is light to dark brown. Bush hyraxes have a light gray to brown fur, ventral color is white or creamy, in distinct contrast to the sides, back, head, and rump. Eyebrows are strikingly white to creamy and conspicuous at a distance. In tree hyraxes, the coat is thick, coarse, dark brown, gray-brown, or black, and with scattered lighter yellowish hairs. D. dorsalis can be distinguished from other members of the genus by a shorter, coarser hair, longer dorsal patch, naked rostrum, and white spot beneath the chin.

Eyes are bulging, the head is flat dorsally, and the muzzle is skunk-like. A pair of upper incisors is tusk-like, ridged, or triangular in cross-section in males. The faces of these incisors are rounded in females. A space (diastema) 0.39–0.47 in (10–12 mm) long in adults precedes the molar teeth that bear transverse cusps adapted for a herbivorous diet.

The pupil of the eye houses a shield (umbraculum) that allows a basking individual to stare into the sun to detect aerial predators.

The digestive system is complex, with three separate areas of microbial fermentation for the food: the fore stomach, the caecum, and the paired colonic appendages.

Body temperature typically ranges from 95 to 98.6°F (35–37°C), but fluctuates up to 12°F (7°C) with air temperature. At air temperatures above 77°F (25°C) body temperature is maintained by evaporative water loss from the nostrils, soles of the feet, panting, salivating, and grooming. Little free water is consumed because of the low metabolic rate, low urine volume, and thermal lability.

Hyraxes conserve energy by having a low metabolic rate and a labile body temperature. The metabolic rate is 30% lower than that predicted on a weight basis, while the labile body temperature suggests a strategy adopted by larger animals such as an eland. The labile body temperature is activated by acclimatization and not by a rhythmic daily drop in body temperature.

As hyraxes have the habit of urinating in the same place, crystallized calcium carbonate forms deposits that whiten the cliff faces below latrines. The precipitated calcium oxylate where urine soaked through the dung heaps and then crystallized where it seeped out was used as medicine (hyraceum) by several South African tribes and by European settlers.

Testes are permanently abdominal and the uterus is duplex. Average distance between anus and penis is 3.1 in (8 cm) in bush hyraxes, 1.3 in (3.5 cm) in rock hyraxes, and 0.7 in (2 cm) in tree hyraxes. Anatomy of the bush hyrax penis is complex, and the penis measures less than 2.3 in (6 cm) when fully erected.

Female rock and bush hyraxes have one pair of pectoral and two pairs of inguinal mammae. Some tree hyraxes have the same number, while other subspecies have one pair pectoral and one pair inguinal.

Individuals dust-bathe to remove external parasites. In addition to the modified claw on the second digit of the hind foot, the four lower incisors are comb-like for grooming the fur.

The adult males of all three genera produce distinctive and loud calls (territorial calls), which can be used as a simple and confident method of locating and recognizing different species. In the tree hyrax, the differences in the characteristics of calls can even be used to differentiate between subspecies.

Ears are small and rounded and may be tipped with white. The tail does not extend past end of body.

Distribution

Hyraxes are endemic to Africa with the exception of bush hyrax found in Sinai and the rock hyrax from Lebanon to Saudi Arabia. Rock and bush hyraxes are dependent on the presence of suitable refuges in rocky outcrops (kopjes), piles of large boulders, and cliffs. These rock outcrops can provide a constant, moderate temperature 62.6–77°F (17–25°C) and humidity (32–40%), and protection from fire.

Rock hyraxes live in a wide range of habitats, from arid deserts to rainforests, and from sea level to the alpine zone of Mt. Kenya (10,500–13,800 ft [3,200–4,200 m]). Bush hyrax is found in parts of north and northeast Africa and the Sinai, east and south from Egypt to South Africa, and from Namibia to Congo. H. b. antineae is isolated in Algeria.

Tree hyraxes are found in arboreal habitats, but in the alpine areas (up to 14,763 ft [4,500 m]) of the Ruwenzori Mountains in Uganda and Congo, they are also rock dwellers. The eastern tree hyrax (D. validus) might be the earliest type of forest-living tree hyrax, being a member of the primitive fauna and flora of the islands of Zanzibar and Pemba in East Africa.

Habitat

Hyraxes adapt to any shelter that provides adequate protection from predators and the elements. Their occurrence, distribution, and numbers depend upon a combination of several abiotic factors such as rainfall and availability of holes and hiding places and biotic factors such as interspecific and intraspecific competition for food, predation, and parasites.

Rock hyraxes are dependent on the presence of suitable refuges in mountain cliffs and rocky outcrops. In several parts of Africa, bush and rock hyraxes occur together and live in close associations. For example, in the Serengeti National Park, rock and bush hyraxes are the most important resident herbivores of the kopjes (rock outcrops). Their numbers depend on the size of the kopje. The population density of rock hyraxes range 5–56 individuals, for bush hyraxes from 20–81 animals per 2.5 ac (1 ha) of kopje, and group size varies 5–34 for the former and 2–26 for the latter. In the Matobo National Park in Zimbabwe, density of P. capensis was estimated at 0.5–1.1 individuals/2.5 ac (1 ha) (1.2–2.6/2.5 ac [ha] of kopje) over a five-year period. This population consisted of 19.4–27.5% juveniles, 7.2–13.1% sub-adults, and 62.9–73.7% adults. Juvenile mortality was estimated at 52.4–61.3%.

These long-term observations have shown that in the Serengeti and Matobo, hyrax populations fluctuate and small colonies are prone to extinction.

In Karoo National Park in South Africa, a strong link between drought and increased predation seems to be the causative agents for hyrax decline. The erratic rainfall is directly responsible for annual variation in hyrax recruitment, and thus population structure. This relationship may have been more responsible for irregularities in the age distribution than the variable mortality, which can affect all age classes. As rainfall precedes the birth season, it shows a close relationship with recruitment. Recent rains have an effect on the moisture of vegetation, and thus on the quality and quantity of milk of lactating females.

Tree hyraxes are found in moist forests, moist savannas, riverine vegetation, and montane habitats. At higher elevations, they can live among rock formations and are partly diurnal. Individuals maintain territories, but population densities and structure are poorly known. In the Mau Forest in Kenya, the density of D. arboreus varied between 1.3–6.2 animals/2.5 ac (1 ha), depending on the type of forest. In Mt. Kilimanjaro, the density of D. validus at three different sites was of 13, 23, and 70 animals/2.5 ac (ha).

External parasites such as ticks, lice, mites, and fleas, and internal parasites such as nematodes, cestodes, and anthrax play a role in hyrax mortality. In the Serengeti, the sarcoptic mite, that causes mange, is an important cause of mortality for rock hyraxes. In West Africa, tree hyraxes have been found to have nematode parasites (Crossophorus collaris, Libyostrongylus alberti, Hoplodontophorus flagellum, and Theileriana brachylaima).

The most important avian predator for rock and bush hyraxes in certain parts of Africa is the black, or Verreaux's, eagle (Aquila verreauxii), which feeds almost exclusively on hyraxes. This eagle preys on hyrax despite low availability. They remove substantial numbers, limit their population growth, and exert hard selection on adult hyraxes as observed in Karoo National Park. Other predators are martial and tawny eagles, leopards, lions, jackals, spotted hyena, and several snake species. In South Africa, the caracal is the second most important predator of hyrax, which can comprise more than 50% of its food.

Predators of the tree hyrax are the African crowned eagles (Stephanoaetus coronatus), leopards (Panthera pardus), and possibly also larger eagle owls (Bubo spp.) or hawk-eagles (Hieraaetus spp.). Chimpanzees have also been documented capturing and killing adult D. dorsalis, but have not been seen to eat them.

Behavior

Rock and bush hyraxes are diurnal and gregarious, but tree hyraxes are mainly nocturnal and usually solitary, although groups of two to three animals can be found.

The basic social unit of rock and bush hyraxes is a cohesive and stable polygynous harem, with a territorial adult male, up to 17 adult females, and juveniles. The territorial male repels all intruding males from an area largely encompassing the females' core area. The adult sex ratio is skewed in favor of females, but the sex ratio of newborns is 1:1.

In the Serengeti bush hyraxes, there are four classes of mature males: territorial, peripheral, and early and late dispersers. Territorial males are the most dominant. Their aggressive behavior toward other adult males escalates in the mating season when the weight of their testes increases 20-fold. These males monopolize receptive females and show a preference for copulating with females over 28 months of age. A territorial male monopolizes "his" female group year round and repels other males from sleeping holes, basking places, and feeding areas. Males can fight to the death, although this is quite rare. While his group members feed, a territorial male will often stand guard on a high rock and be the first to call in case of danger. Males utter the territorial call all year round.

Peripheral males are those unable to settle on small kopjes, but on large kopjes can occupy areas on the periphery of the territorial males' territories. They are solitary, and the highest ranking among them takes over a female group when a territorial male disappears. These males show no seasonality in aggression, but call only in the mating season. Most of their mating attempts and copulations are with females younger than 28 months. The majority of juvenile males— the early dispersers—leave their birth sites at 16–24 months old, soon after reaching sexual maturity. The late dispersers leave a year later, but before they are 30 months old. Before leaving their birth sites, both early and late dispersers have ranges that overlap their mothers' home ranges. They disperse in the mating season to become peripheral males. Almost no threat, submissive, or fleeing behavior has been observed between territorial males and late dispersers.

Larger kopjes may support several family groups, each occupying a traditional range. The females' home ranges are not defended and may overlap. Rarely, an adult female from outside a group will be incorporated into the family group. In the bush hyrax, these immigrants are responsible for bringing new alleles into local populations, preventing inbreeding, and consequently reduce the risk of local extinction.

Individuals of rock and bush hyraxes were observed to disperse over a distance of at least 1.2 mi (2 km). However, the further a dispersing animal has to travel across the open grass plains, where there is little cover and few hiding places, the greater are its chances of death, either through predation or as a result of its inability to cope with temperature stress. First results on DNA analysis of rock hyraxes in the Serengeti show almost no genetic variation between colonies.

Body temperature is maintained mainly by gregarious huddling, long periods of inactivity, and basking. Although their physiology allows them to exist in very dry areas and use food of relatively poor quality, they are dependent on shelters (boulders and tree cavities) that provide relatively constant temperature and humidity.

Where both species live together, they huddle together in the early mornings after spending the night in the same holes. They also use the same urination and defecation sites. Parturition tends to be synchronous, and the two species cooperate. Newborns are greeted and sniffed intensively by members of both species, and they form a nursery group and play together. Most of their vocalizations are also similar. However, bush and rock hyraxes do differ in key behavior patterns. They do not interbreed because their mating behavior is different, and they have different reproductive anatomy. The male territorial call, which might function as a "keep out" sign, is also different. Finally, the bush hyrax browses on leaves, but the rock hyrax feeds mainly on grass. The latter is probably the main factor that allows both species to live together.

Tree hyraxes live primarily solitary, but groups of two and three can be found (likely mother and sub-adult young). They have small home ranges, with each defended male territory overlapping those of several smaller female ranges. Individuals in captivity rubbed dorsal glands, probably used in the wild to mark territory boundaries and individual identification. Individuals use latrines, defecating repeatedly at the bases of trees. Largely inactive, they emerge regularly at dusk and have another period of activity before daylight. Tree hyraxes produce loud and distinct calls, characterized by long cries, repeated between 22 and 42 times at gradually increasing amplitude and intervals, reaching a loud crescendo at the end. They call throughout the night, but with marked peaks in late evening and early morning corresponding with the activity patterns. They are also heard to call during the day, normally after being disturbed.

Feeding ecology and diet

Hyraxes are herbivorous, consuming mostly leaves, twigs, fruit, and bark. Hyraxes do not ruminate. Their gut is complex, with three separate areas of microbial digestion, and their ability to digest fiber efficiently is similar to that of ruminants. Their efficient kidneys allow them to exist on minimal moisture intake. In addition, they have a high capacity for concentrating urea and electrolytes and excreting large amounts of undissolved calcium carbonate.

Rock hyraxes in the Serengeti were observed feeding on 79 plant species. The animals have a high seasonal adaptability: in the wet season, they showed a high preference for grasses (78%), but in the dry season when grasses became parched and poor in quality, they browsed (57%) extensively, and more or less in proportion to the foliage density of each vegetation class. As rock hyraxes feed mainly on grass, which is a relatively coarse material because of phytoliths (plant opal), their molars and premolars are hypsodont, i.e., they have high crowns with relatively shorter roots.

Bush and tree hyraxes are obligate browsers. In the Serengeti, bush hyraxes were observed feeding on 64 plant species, but two to 11 species formed 90% of the animal's staple diet. They browsed leaves, buds, flowers, and fruits of trees, bushes, and herbs predominantly in the wet (81%) and dry (92%) season. Browse material is softer than grass. This difference is shown in the brachydont dentition (short crowns with relatively long roots) of bush and tree hyraxes.

Examination of ¹³C:¹²C ratios of carbonate and collagen fractions of bone and microwear patterns of the molariform teeth confirmed that the bush hyrax is a browser and the rock hyrax switches between grazing and browsing.

Most feeding occurs between 7:30 and 11 a.m. and 3:30 and 6 p.m., but occasionally to 9 p.m. Individuals may feed alone or in a group. Group feeding can occur up to 164 ft (50m) from the center of the colony, although casual feeding rarely occurs at distances greater than 65.6 ft (20 m) from the den site. Feeding bouts average 20 minutes and last no longer than 35 minutes. Individuals can climb vertical trunks of trees and balance on thin branches to strip the vegetation of leaves.

Territorial male rock and bush hyraxes usually show sentinel behavior by sitting on a high rock or tree branch while the family is group feeding. This is the time when hyraxes are most vulnerable to predation because they venture furthest from shelter. The guarding animals are often the first to give a warning or alarm call in case of a sudden danger, whereupon the feeding animals take cover immediately. At group feeding times, individuals of both species may guard simultaneously; the warning or alarm call of either species is acted upon by all animals.

Reproductive biology

Females have six pairs of teats, one pair pectoral and two pairs inguinal. Females become receptive once a year, and a peak in births seems to coincide with rainfall. Before mating, a bush hyrax male emits a shrill cry while approaching the female, and she erects her dorsal spot hairs. The male sniffs the female's vulva, rests his chin on her rump, then slides onto her back as he makes thrusting movements followed by intromission

in three to five minutes. A second copulation may occur in one to three hours.

Territorial bush hyrax males copulate more often than peripheral males and mate preferentially with females younger than 28 months of age. Peripheral males exhibit a dominance hierarchy and mate more often with young females in a polygynous system.

Gestation is between 26 and 30 weeks. Within a family group, the pregnant females all give birth within a period of about three weeks. The number of young per female bush hyraxes ranges from one to three, and in rock hyraxes from one to four. In tree hyraxes, one to two young are born. Litter size is smaller in Dendrohyrax than other hyrax genera. In southern Africa, a female rock hyrax with six embryos has been collected. Numbers depend on the size (age) of the mother; first breeders have only one to two.

The young are precocial, being fully developed at birth, and weigh 6.35–13.4 oz (180–380 g). Mothers suckle only their own as the young assume a strict teat order. Weaning occurs at one to five months, and both sexes reach sexual maturity at about 16–17 months of age. Upon sexual maturity, females usually join the adult female group, while males disperse before they reach 30 months. Adult females live significantly longer than adult males and may reach an age of more than 11 years.

A study on shot samples in the Karoo indicated a relatively high incidence of adult males in the study population, which appears to be an effect of drought. Rock hyrax males pre dominated in age classes that were born during dry conditions, while females predominated in age classes born during wet conditions. This difference might be due to late fetal reabsorption or mummification in the uterus. The ability to reabsorb fetuses at a late stage would be highly adaptive for hyraxes in an unpredictable environment.

Play behavior of the young consists of nipping, biting, climbing, pushing, fighting, chasing, and mounting. When rock and bush hyraxes live together, young of both species will play. Young in nurseries are attended by their own mothers, mothers of other young, non-maternal conspecifics, or even individuals from the other species.

In tree hyrax, both mating and birth peaks tend to coincide with the dry season, but offspring may be born throughout the year. Females excrete cinnamon-smelling oil from their dorsal gland prior to mating. Young reach sexual maturity around 16 months of age. Lifespan is poorly known, although captive animals have been reported to live up to 12 years.

Conservation status

Dendrohyrax validus, Heterohyrax antinea, and H. chapini are currently categorized as Vulnerable in the IUCN Red List. Others have no special status for IUCN, CITES, or U.S. ESA. All three of the tree hyrax species are probably sensitive to habitat degradation, as they are mainly confined to primary forests in Africa. They are killed for their fur and for food, but apparently are widespread and common in large forest tracks. According to the African Mammals Database, only about 6% of geographical range of D. dorsalis is protected. D. validus is heavily hunted for its fur in the forest belt around Mt. Kilimanjaro.

Significance to humans

The rock hyrax is mentioned several times in the Bible: Solomon says they are "wise" (Proverbs 30:26) because "the conies are a feeble folk, yet they make their houses in the rocks." And, "The high mountains are for the wild goats; the rocks are a refuge for the conies" (Psalms 104:18).

In Phoenician and Hebrew, hyraxes are known as shaphan, meaning "the hidden one." Some 3,000 years ago, Phoenician seamen explored the Mediterranean, sailing westward from their homeland on the coast of Syria. They found land where they saw small mammals, which they thought were hyraxes, and so they called the place "I-shaphan-im"—Island of the Hyrax. The Romans later modified the island's name to Hispania.

Several African tribes hunt, snare, or trap hyrax as a food source and for the skin. The Hadza or Watindiga, a Bushman tribe in Tanzania, hunt rock and bush hyraxes. Hadza boys catch a newborn hyrax and, when caused some pain, the young animal emits a loud bird-like chirrup distress call, which incites adult females and males to leave the safe holes or cracks to help and are then shot with arrows. The most common principle for catching D. arboreus in the Mau Forest in Kenya was to dislodge the animals from the trees and then kill them on the ground. The meat is eaten and the skin collected. It is estimated that the total off-take for the southwest Mau area per year is 16,000 hyraxes, representing about a quarter of the annual population increment. In the forest belt around Mt. Kilimanjaro, the eastern tree hyrax is heavily hunted for its skin; 48 animals yield one rug.

The forest dwelling people of the southwest Mau use tree hyrax in the traditional medicine as a means of prevention and to cure a number of ailments. The principal medicinal use was to cure deep coughing by drinking the ash of burnt hairs mixed with water or honey. In rituals, hyrax also played a role. Some clans traditionally bless their newborn babies by wrapping them in hyrax skins to ensure good health. Hyraxes are also regarded as an omen.

In Kenya and Ethiopia, rock and tree hyraxes might be an important reservoir for the parasitic disease cutaneous leishmaniasis, which can also affect humans.

Species accounts

List of Species

Southern tree hyrax

Dendrohyrax arboreus

taxonomy

Dendrohyrax arboreus (A. Smith, 1827), Cape of Good Hope, South Africa. Eight subspecies have been described.

other common names

English: Tree dassie; French: Daman d'arbre; German: Baumschliefer; Spanish: Daman de árbol.

physical characteristics

Head and body length 12.5–24 in (32–60 cm); weight 3.7–9.9 lb (1.7–4.5 kg). Males and females are approximately the same size. Coat is long, soft, and dark brown; dorsal spot light to dark yellow, from 0.9–1.2 in (23–30 mm) long. Number of mammae variable. Longevity over 10 years.

distribution

Found in the evergreen forests of the eastern Cape Province and the Natal midlands of South Africa; northwestern Zambia; northeastern and eastern Zambia; eastern Congo; northwestern Tanzania; Burundi and Rwanda; western Uganda; central and southern Kenya.

habitat

Evergreen forests up to about 13,500 ft (4,500 m). In the Ruwenzori, they live also among rock boulders.

behavior

Nocturnal and live primarily solitary, but groups of two and three can be found (likely mother and subadult young). Individuals

maintain territories, but population densities and structure poorly known.

feeding ecology and diet

Herbivorous, browsing leaves, buds, twigs, fruits from forbs and trees all year-round.

reproductive biology

Not well known. Gestation: 220–240 days; one to two young per female.

conservation status

Not threatened.

significance to humans

Certain African tribes hunt hyrax as a source of food, to collect skins, and as medicine. For some tribes it is also important in their spiritual traditions.

Western tree hyrax

Dendrohyrax dorsalis

taxonomy

Dendrohyrax dorsalis (Fraser, 1854), Bioko, Equatorial Guinea. Six subspecies have been described.

other common names

English: Tree dassie; French: Daman d'arbre; German: Baumschliefer; Spanish: Daman de árbol.

physical characteristics

Head and body length 12.5–24 in (32–60 cm); weight 3.7–9.9 lb (1.7–4.5 kg). Males and females are approximately the same size. Coat is long, soft, and dark brown; dorsal spot light to dark yellow, from 1.6 to 2.9 in (40–75 mm) long. One pair of inguinal mammae only.

distribution

Found on Fernando Po; the West African coastal forests from Gambia to Angola; central and northeastern Congo, and northern Uganda.

habitat

Found in moist forests up to about 12,000 ft (3,650 m), moist savannas, and montane habitats.

behavior

Nocturnal and live primarily solitary, but groups of two and three can be found (likely mother and subadult young). Individuals maintain territories, but population densities and structure poorly known.

feeding ecology and diet

Herbivorous, browsing leaves, buds, twigs, fruits from forbs and trees all year-round.

reproductive biology

In the tree hyrax both mating and birth peaks tend to coincide with the dry season, but offspring may be born throughout the year. Gestation: 220–240 days; one to two young per female.

conservation status

Not threatened.

significance to humans

Certain African tribes hunt hyrax for food and for their skin.

Eastern tree hyrax

Dendrohyrax validus

taxonomy

Dendrohyrax validus True, 1890, Mt. Kilimanjaro, Tanzania. Two subspecies have been described: D. v. validus on the continent and D. v. neumanni on the islands of Pemba, Zanzibar and Tumbatu.

other common names

English: Tree dassie; French: Daman d'arbre; German: Baumschliefer; Spanish: Daman de árbol; Kiswahili: Perere.

physical characteristics

Head and body length 12.5–24 in (32–60 cm); weight 1.7–4.0 kg (3.7–8.0 lb). Males and females are approximately the same size. Coat is long, soft and very dark brown, dorsal spot light to dark yellow, from 0.8 to 1.6 in (20–40 mm) long. One pair of inguinal mammae. Longevity unknown.

distribution

Kilimanjaro, Mt. Meru, Usambara, Zanzibar, Pemba, and the relict forests of the Kenyan coast.

habitat

Evergreen forests up to about 11,500 ft (3,500 m). On the Kenyan coast they live in the fossil reef area.

behavior

Tree hyraxes are nocturnal and live primarily solitary but groups of two and three can be found (likely mother and

subadult young). Population densities in the Kilimanjaro varies 7–23 animals/2.5 acres (1 ha).

feeding ecology and diet

herbivorous, browsing leaves, buds, twigs, fruits from forbs and trees all year round.

reproductive biology

Not known. Gestation: 220–240 days; one to two young per female.

conservation status

Listed as Vulnerable on the IUCN Red List.

significance to humans

African tribes hunt hyraxes as a source of food. In the Kilimanjaro area, they are hunted extensively for their skins, which have commercial value.

Bush hyrax

Heterohyrax brucei

taxonomy

Heterohyrax brucei (Gray, 1868), Ethiopia. Twenty-five sub-species have been described.

other common names

English: Bush dassie, yellow-spotted rock hyrax, yellow-spotted hyrax, klipdassie; French: Daman d'arbuste; German: Buschschliefer; Spanish: Daman de arbusto.

physical characteristics

Head and body length 12.5–18.5 in (32–47 cm); weight 2.9–5.3 lb (1.3–2.4 kg). Males and females are approximately the same size. Average distance between anus and penis is 3.1 in (8 cm). Coat is light gray to brown; ventral color is white or creamy in distinct contrast to the sides, back, head, and rump. Eyebrows are strikingly white to creamy and conspicuous at a distance.

distribution

Found in parts of northeast Africa and the Sinai; east to south, from Egypt to South Africa and Namibia to Congo. H. b. antineae might occur isolated in Algeria and central Sahara.

habitat

Adapt to any shelter that provides adequate protection from predators and the elements. Rock boulders and outcrops in different vegetation zones in Africa, sometimes in hollow trees.

behavior

Diurnal and gregarious, the social unit being a polygynous harem, with a territorial adult male, several adult females, and juveniles.

feeding ecology and diet

Herbivorous, browsing leaves, buds, twigs, and fruits all year-round.

reproductive biology

Females become receptive once a year, and a peak in births seems to coincide with rainfall. Polygynous. Gestation: 212–240 days; one to three young per female. Weaning at one to five months, and both sexes reach sexual maturity at about 16–17 months of age. Longevity: 9–12 years. Adult females live significantly longer than adult males.

conservation status

Not threatened.

significance to humans

Certain African tribes hunt hyrax for food.

Rock hyrax

Procavia capensis

taxonomy

Procavia capensis (Pallas, 1766), Cape of Good Hope, South Africa. Four subspecies identified.

other common names

English: Klipdassie; French: Daman les roches; German: Klippschliefer; Spanish: Damán de rocas.

physical characteristics

Head and body length 17–21 in (44–54 cm); weight 4–12 lb (1.8–5.4 kg). Males and females are approximately the same size. Mean distance between anus and penis 1.3 in (3.5 cm). Coat is light to dark brown; the dorsal spot is light creamy to yellow-colored in all species, with the exception of the rock hyrax of southern Africa, where it is not conspicuous.

distribution

Southwest and northeast Africa, Sinai to Lebanon, and southeast Arabian Peninsula.

habitat

Dependent on the presence of suitable refuges in mountain cliffs and rocky outcrops. Live in a wide range of habitats, from arid deserts to forests, and from sea level to the alpine zone of Mt. Kenya (10,500–13,800 ft [3,200–4,200 m]).

behavior

Diurnal and gregarious, the social unit being a polygynous harem, with a territorial adult male, several adult females, and juveniles.

feeding ecology and diet

Herbivorous, consuming mostly leaves, twigs, fruit, and bark. The animals have a high seasonal adaptability: during the rainy season, they have a high preference for grasses, but in the dry season, they browse extensively.

reproductive biology

Females become receptive once a year, and a peak in births seems to coincide with rainfall. Polygynous. Gestation: 212–240 days; one to four young per female. Weaning at one to five months, and both sexes reach sexual maturity at about 16–17 months of age. Longevity: 9–12 years. Adult females live significantly longer than adult males.

conservation status

Not threatened.

significance to humans

Certain African tribes hunt hyraxes for food. Mentioned several times in the Bible as "conie."

Resources

Books

Barry, R., and H. N. Hoeck. "Heterohyrax brucei." In The Mammals of Africa: A Comprehensive Synthesis, edited by Jonathan Kingdon, David Happold, and Thomas Butynski. London: Academic Press, 2003.

Bothma, J. P. "Du Hyracoidea." In Preliminary Identification Manual of African Mammals, edited by P. J. Meesters. Washington DC: Smithsonian Institution, 1966.

Davies, R. A. G. "Black Eagle (Aquila verrauxii) Predation on Rock Hyrax (Procavia capensis) and Other Prey in the Karoo." Unpublished PhD Dissertation. University of Pretoria, Pretoria, South Africa. 1994.

Fischer, M. S. "Hyracoidea." Handbuch der Zoologie. Band VIII Mammalia. Berlin and New York: Walter de Gruyter, 1992.

Gargett, V. The Black Eagle: A Study. Randburg, South Africa: Acorn Books, 1990.

Hoeck, H. N. Systematics of the Hyracoidea: Towards a Clarification. Pittsburgh: Bulletin Carnegie Museum of Natural History, 1978.

——. "Procavia capensis." In The Mammals of Africa: A Comprehensive Synthesis, edited by Jonathan Kingdon, David Happold, and Thomas Butynski. London: Academic Press, 2003.

Kingdon, J. East African Mammals. An Atlas of Evolution in Africa. London: Academic Press, 1971.

Roberts, D., E. Topp-Jorgensen, and D. Moyer. "Dendrohyrax validus." In The Mammals of Africa: A Comprehensive Synthesis, edited by Jonathan Kingdon, David Happold, and Thomas Butynski. London: Academic Press, 2003.

Schultz, D., and D. Roberts. "Dendrohyrax dorsalis." In The Mammals of Africa: A Comprehensive Synthesis, edited by Jonathan Kingdon, David Happold, and Thomas Butynski. London: Academic Press, 2003.

Periodicals

Bartholomew, G., and M. Rainy. "Regulation of Body Temperature in the Rock Hyrax (Heterohyrax brucei)." Journal of Mammalogy 52, 1994: 81–95.

Barry, R. E. "Synchronous Parturition of Procavia capensis and Heterohyrax brucei during Drought in Zimbabwe." South African Journal of Wildlife Research 24 (1994): 1–5.

Barry, R. E., and P. J. Mundy. "Population Dynamics of Two Species of Hyraxes in the Matobo National Park, Zimbabwe." African Journal of Ecology 36, (1998): 221–233.

Barry, R. E., and J. Shoshani. "Heterohyrax brucei." Mammalian Species no. 645 (2000): 1–7.

Coetzee, C. "The Relative Position of the Penis in Southern African Dassies (Hyracoidea) as a Character of Taxonomic Importance." Zoologica Africana 2, (1966): 223–224.

De Niro, M. J., and S. Epstein. "Carbon Isotopic Evidence for Different Feeding Patterns in Two Hyrax Species Occupying the Same Habitat." Science 201, no. 4359 (1978): 906–908.

Gerlach, G., and H. N. Hoeck. "Island on the Plains: Metapopulation Dynamics and Female Based Dispersal in Hyraxes (Hyracoidea) in the Serengeti National Park." Molecular Ecology 10 (2001): 2307–2317.

Hoeck, H. N. "Demography and Competition in Hyrax: A 17-year Study." Oecologia 79 (1989): 353–360.

——. "Differential Feeding Behaviour of the Sympatric Hyrax Procavia johnstoni and Heterohyrax brucei." Oecologia 22(1975): 15–47.

——. "Population Dynamics, Dispersal and Genetic Isolation in Two Species of Hyrax (Heterohyrax brucei and Procavia johnstoni) on Habitat Islands in the Serengeti." Zeitschrift für Tierpsychologie 59 (1982): 177–210.

——. "Teat Order in Hyrax (P. johnstoni and H. brucei)." Zeitschrift für Säugetierkunde 42, (1977): 112–115.

Hoeck, H. N., H. Klein, and P. Hoeck. "Flexible Social Organization in Hyrax." Zeitschrift für Tierpsychologie 59(1982): 265–298.

Janis, C. M. "New Ideas in Ungulate Phylogeny and Evolution." Trends in Ecology and Evolution 3, no. 11 (1988).

Jones, C. "Dendrohyrax dorsalis." Mammalian Species 113 (1978): 1–4.

Klein, R. G., and K. Cruz-Uribe. "Size Variation in the Rock Hyrax (Procavia capensis) and Late Quaternary Climatic Change in South Africa." Quaternary Research 46 (1996): 193–207.

Milner, J. "Relationships between the Forest Dwelling People of South-West Mau and the Tree Hyrax Dendrohyrax arboreus." Journal of East African Natural History 83 (1994): 17–29.

Olds, N., and J. Shoshani. "Procavia capensis." Mammalian Species 171 (1982): 1–7.

Prinsloo, P., and T. J. Robinson. "Geographic Mitochondrial DNA Variation in the Rock Hyrax, Procavia capensis." Molecular Biology and Evolution 9 (1992): 447–456.

Rübsamen K., I. D. Hume, and W. V. Engelhardt. "Physiology of the Rock Hyrax." Comparative Biochemical Physiology 72A (1982): 271–277.

Seibt, U., H. N. Hoeck, and W. Wickler. "Dendrohyrax validus, True, 1890 in Kenia." Zeitschrift für Säugetierkunde 42(1977): 115–118.

Springer, M. S., et al. "Endemic African Mammals Shake the Phylogenetic Tree." Nature 388 (1997): 61–64.

Walker A., H. N. Hoeck, and L. Perez. "Microwear of Mammalian Teeth as an Indicator of Diet." Science 201(1978): 908–910.

Yang, F., et al. "Reciprocal Chromosome Painting among Human, Aardvark, and Elephant (Superorder Afrotheria) Reveals the Likely Eutherian Ancestral Karyotype." Proceedings of the National Academy of Sciences 100, no. 3(2003): 1062–1066.

Other

Afrotheria Specialist Group. [April 2003]. <http://www.calacademy.org/research/bmammals/afrotheria/ASG.html>.

Hoeck, H. N. "Ethologie von Busch- und Klippschliefer." Film D 1338 des Institut für den Wissenschaftlichen Film, Göttingen 1980. Publikation von H. N. Hoeck, Publikation Wissenschaftlicher Film, Sektion Biologie, Serie 15, Number 32/D1338 (1982), 24 Seiten.

——. "Nahrungsökologie bei Busch- und Klippschliefern." Sympatrische Lebensweise. Film D 1371 des Institut für den Wissenschaftlichen Film, Göttingen 1980. Publikation von H. N. Hoeck, Publikation Wissenschaftlicher Film, Sektion Biologie, Serie 15, Nr. 32/D1371 (1982), 19 S.

Hyrax: Behavioural Ecology of Two Species. [April 2003]. <http://www.mpi-seewiesen.mpg.de/knauer/hoeck/klip.html>.

Hendrik Hoeck, PhD