Procavia capensis
rock hyrax

Procavia capensis occurs throughout most of Africa and the Arabian Peninsula with the exception of the Congo basin and Madagascar. Being the most arid-adapted of hyrax species, its range includes mountainous regions in the Namib, Sahara, and Arabian deserts. (Bartholomew and Rainy, 1971; Estes, 1991; Hoeck, 1975; Olds and Shoshani, 1982)

Procavia capensis lives in rocky areas with moderate vegetative cover, and many rock crevices and cavities, the latter of which are used as shelter. Although it does not burrow, it is known to inhabit abandoned burrows, including those of aardvarks and meerkats. Even when traveling between suitable habitats, rock hyraxes do not normally stray from areas with some form of cover or refuge. This species is commonly found in arid land habitat including deserts, savannas and scrub forests. (Estes, 1991; Hoeck, 1975; Olds and Shoshani, 1982)

Hyraxes are the smallest of the subungulate mammals (i.e., animals who share a common ancestor with ungulates) and are similar in appearance to a woodchuck. The dorsum of Procavia capensis is covered in grizzled reddish brown fur that becomes increasingly light as it approaches the venter. It has a single pair of long, strong, tusk-like incisors and molars that are similar to the cheek teeth of rhinoceroses. The feet are plantigrade (fore) to semi-digitigrade (hind). The soles of the feet have soft, large pads that are kept moist with sweat-like secretions. Total length for adults ranges from 305 to 550 mm and tail length ranges from 11 to 24 mm. Hindfoot length ranges from 65 to 76mm and ear length ranges from 27 to 38 mm. They are heavily built for their size, weighing as much as 4.3 kg. Males (4 kg) are slightly larger than females (3.6 kg) and have blunter features and thinner bodies with thicker necks than females do. The tusks of males are larger and sharper than those of females. Males also have a larger larynx and larger guttural pouches, which help to amplify their territorial calls. Hyrax eyes contain a special membrane called the umbraculum that is thought to shield the eye from the sun. (Estes, 1991; Olds and Shoshani, 1982; Skinner and Chimimba, 2005)

The forefeet of Procavia capensis have four toes and are plantigrade, while the hindfeet have three toes and are semi-plantigrade. All of the toes have rounded nails resembling hooves, except the inside rear toe, which is equipped with a claw that is used in grooming. Procavia capensis has mesaxonic feet in which the plane of symmetry passes through the third digit. The soles of the feet have large, black pads that are moistened by sweat glands, increasing their cohesion to rocky substrates. (Bartholomew and Rainy, 1971; Estes, 1991; Olds and Shoshani, 1982)

The coat of Procavia capensis is dense and rough, with a thick undercoat and long guard hairs scattered throughout. Long, black vibrissae, used as haptic receptors, are found on the back and around the mouth. Pelage color is highly variable among subspecies, ranging from gray, to yellow-brown, to dark brown. The dorsum is usually darker than the flanks, and the venter tends to be a lighter cream-color. In the cape region of Africa, pelage color corresponds with moisture in the environment; animals living in wetter areas have darker coats, and those living in more arid regions have lighter coats. The coat contains a patch on the back surrounded by longer hairs in a contrasting color that may be black, yellow, or orange. Underneath this patch is a bare spot containing a dorsal gland specific to hyraxes that secretes pheromones, which are likely used to mark rocks and help young imprint on their mother. Pheromone production is most pronounced during mating season. (Estes, 1991; Olds and Shoshani, 1982)

Little information is available regarding the average lifespan of Procavia capensis, however, evidence suggests it can live for up to 12 years in the wild. (Estes, 1991)

Procavia capensis is gregarious and lives in colonies with as many as 80 individuals, depending home range size and resource abundance. Herds are typically comprised of a territorial male that controls a harem of several related females and their offspring, but may consist of a multiple families, each headed by an adult male. Females are usually philopatric, and may associate with each other indefinitely. Female emigration is rare, but dispersing females have been accepted into other colonies after an initial period of hostility from resident females. There is no defined dominance hierarchy among females, but older individuals tend to be the more dominant and vigilant than younger individuals. (Estes, 1991; Hoeck, 1975; Olds and Shoshani, 1982)

Within individual rock hyrax colonies, territorial males dominate over all colony members and remain on alert for predators and conspecific rivals. Male offspring are forced to disperse by 30 months of age, but usually disperse by 17 to 24 months of age. Territorial males are relatively tolerant of their own male offspring, but are very aggressive towards dispersing males, which may travel more than 2 km in search for of undefended habitat. In most cases, there is no acceptable habitat nearby and young males are forced to defend sleeping holes on the periphery of the colony's territory. When the territorial male dies or becomes weakened, the top peripheral male replaces him. (Estes, 1991; Hoeck, 1975; Hoeck, 1989)

Despite being endothermic, rock hyraxes have a widely fluctuating body temperature and cannot exist without shelter from temperature extremes. They employ many of the same behavioral adaptations as reptiles to avoid extreme temperatures. Unless the weather is very warm, they do not leave their burrows until morning when they typically spend an hour or so sunbathing. Foraging occurs after sunbathing and during the afternoon, with most feeding occurring in the evening. They often avoid the warmest part of the day by resting in shade. Rain is also avoided, and hyraxes might not leave their dens at all during cold, rainy days. They are sometimes active during moonlit nights. Adult hyraxes spend 95% of their time resting. Resting often involves heaping, which usually takes place inside their den and as animals lay on top of one another. Evidence suggests that resting behavior is correlated with ambient temperature. As temperatures become increasingly warm, resting can be characterized as a progression from heaping to huddling to solitary resting. (Bartholomew and Rainy, 1971; Estes, 1991; Olds and Shoshani, 1982)

Home Range

There is no information available regarding the average home range size of rock hyraxes.

All of the senses of rock hyraxes are well-developed, although their near-vision is thought to be relatively poor. Hyraxes have a variety of vocal calls. Territorial calls are distinct and genus-specific. In rock hyraxes, territorial calls are loud and repetitious and increase in volume and duration towards the end of the sequence before ending in a series of guttural noises. Adults also emit twittering or whinnying calls and striking alarm calls, which are made when a potential predator is identified. When threatened, they may growl or grind their molars. Infants make only five of the twenty-one sounds used by adults; three of these are vocal, including mewing calls given when they are lost or begging, and two are non-vocal. Between 2 to 15 months of age, young develop all vocal sounds except five; four of which are exclusive to adult females and one is characteristic of adult males. (Estes, 1991; Olds and Shoshani, 1982)

Rock hyraxes urinate on the sides of rocks near colony sites. Crystallized calcium carbonate present in the excretion makes a white stain used in visual communication. Hyraxes also deposit their droppings and urine in a common latrine, but it is unknown whether this serves any role in olfactory communication. The dorsal gland and hair surrounding it are important for communication among conspecific. Pheromone production from the dorsal gland increases with increased stimuli. In an aggressive context, pheromone production is accompanied by a slight curling of the upper lip and piloerection of the neck hairs. During territorial calls, males crouch and raise their head with their jaws slightly agape. Hyraxes show submission by presenting their hindquarters, backing away, closing their dorsal gland, and/or flattening their ears. Submissive behaviors are very important, as simple interactions such as approaching or directly staring at another adult might be seen as a threat and the tusks can inflict fatal wounds. To avoid antagonizing other individuals, feeding or huddling individuals usually face away from each other. (Estes, 1991; Olds and Shoshani, 1982)

Rock hyraxes are primarily grazers and forage on many different plant species per foraging bought; however, regional preferences have been documented. For example, giant lobelia and certain daisy species are preferred on the west slope of Mt. Kenya, swampy vegetation is eaten close to the bottoms of valleys, and lowland forage includes new shoots, fruits, berries, and figs. During the wet season, grasses comprise 78% of the diet, but make up only 57% of the diet during the dry season. When conditions are moist, either during the wet season or after a rainfall, rock hyraxes show a preference for new shoots, buds, and leaves. During drought, they may eat coarse material such as bark, lichens, and liverworts. Daily food consumption varies with body weight and plant water content has a significant influence on the amount of food that is ingested. Rock hyraxes may travel up to 60 m from their burrows to forage but may travel further during a drought. When grazing, individuals maintain their spacing and remaining vigilant for potential predators. (Estes, 1991; Hoeck, 1975; Hoeck, 1989; Olds and Shoshani, 1982; Sale, 1966)

The feeding habits of rock hyraxes are comparable to those of ungulates, and giraffes and elephants are their most likley competitors for food. Hyraxes can feed very rapidly and entire colonies may spend less than one hour per day feeding. Most feeding is concentrated in two feeding periods that are about twenty minutes long: one about three hours after sunrise and the other about two hours before sunset. They do not manipulate or carry their food, and they use their feet only to reach or hold twigs. While foraging, they often hold their head at a 90˚ angle to best utilize their wide gape and bite off large amounts of vegetation. By eating large amounts of food quickly, and spending most of their time resting, rock hyraxes are able to survive on resources too sparse or nutrient-poor to support more active mammals of a comparable size. (Estes, 1991; Olds and Shoshani, 1982; Sale, 1966)

Except in high mountainous areas, leopards are the main predator of Procavia capensis. Hyraxes may also be predated upon by snakes (e.g., Egyptian cobras and puff adders), eagles (e.g., Verreaux’s eagles and martial eagles), owls, jackals, African wild dogs, and various cat species (e.g., servals, caracals and lions. Neonates are sometimes preyed upon by mongooses. Procavia capensis evades predators by staying alert and remaining close to cover while foraging. Individuals immediately respond to the alarm calls of territorial male and to the calls of other species such as bush hyraxes and some birds. This species also avoids predators by using burrows that are smaller in diameter than most predators in their habitat. They have been known to escape predation by playing dead, or by working together to scare off smaller predators from the safety of a burrow. (Estes, 1991; Olds and Shoshani, 1982)

Rock hyraxes are the dominant herbivores in rocky areas throughout their geographic range. They are preyed upon by a number of different vertebrate species and are known to host up to 25 species of lice. (Estes, 1991; Olds and Shoshani, 1982)

In areas where humans are prevalent, especially South Africa, rock hyraxes are sometimes considered pests, as they inhabit road culverts and/or crevices in stone walls. Agricultural plots that have been recently cleared are often bordered by rocks that were removed during clearing, thus providing prime habitat for rock hyraxes. Fields such as these are often used for cultivating fruit trees, upon which hyraxes browse and cause considerable damage. In addition, rock hyraxes are a known reservoir for Leishmania tropica, a flagellate parasite that infects rodents and humans. (Estes, 1991; Jacobson et al., 2003; Moran, Sofer, and Cohen, 1987; Olds and Shoshani, 1982; Svobodová, Volf, and Votýpka, 2006)

Members of Procavia capensis colonies urinate and defecate in designated areas called latrine. As time goes on, and more material accumulates, this eventually congeals into a large, sticky solid. This substance has been used in a number of applications including a medicine called hyraceum that has been used to treat epilepsy, convulsions, and a number of female specific diseases. Procavia capensis is hunted for its meat throughout its geographic range. (Olds and Shoshani, 1982)

Although Procavia capensis is classified as a species of least concern on the IUCN's Red List of Threatened Species, current population trends are unknown. While it is hunted for its meat throughout its geographic range and has experienced local extirpations, there are no major threats to the long-term persistence of this species. (Barry et al., 2008)

The word “hyrax” means “shrewmouse” in Greek. The Hebrew word for Procavia capensis, “Shaphan”, roughly translates into “the hidden one.” In Biblical times, hyraxes were known as “conies”. They are also referred to as dassies or rock dassies in Southern Africa. (Estes, 1991; Olds and Shoshani, 1982)