Capra nubiana
Nubian ibex

Capra nubiana, or the Nubian ibex, is the only ibex species adapted to life in hot, arid regions of the world. Capra nubiana was once widespread in the mountainous regions of northeastern Africa and the Middle East. Estimates of the full extent of this geographic range are based on ancient drawings and bone remnants. Presently, C. nubiana occurs in isolated populations in pockets of the coastal regions of northeastern Africa, the Sinai Peninsula, and the southeastern tip and western portion of the Arabian Peninsula. (Mendelssohn, 1990; Osborn and Osbornová, 1998; Shackleton, 1997)

Nubian ibex inhabit mountainous regions including gorges, outcrops, and scree areas in arid regions with sparse vegetation. They occur at varying elevations, from sea level to 3,000 meters. Generally, Nubian ibex inhabit the most remote, highest, and steepest cliffs. (Schaller, 1977)

Nubian ibex are one of the smallest ibex species and are sexually dimorphic. A female ibex is, on average, about one-third the size of a male. Males have an average weight of 62.5 kg, females average 26.5 kg. Shoulder height averages 75 cm in males and 65 cm in females. Total body length is 125 cm in males and 105 cm in females. (Gross, Alkon, and Demment, 1995; Mendelssohn, 1990; Nowak, 1990)

The overall color of Capra nubiana individuals is a uniform tan (matching the surrounding rocky arid environs) with patches of black and white on the legs and a white underbelly. There is a color change that begins in August, where males become dark brown to black on their necks, chests, shoulders, sides of the belly, front side of the thighs, and upper forelegs. Males have long dark beards, which are used for scent marking and to excite the females during rutting. Older females also grow beards. (Gross, Alkon, and Demment, 1995; Mendelssohn, 1990; Nowak, 1990)

Both males and females have horns, which are used for fighting, sexual selection, and territorial defense. A male’s horns are large, dark, and semi-circular, with annual rings on the back. The annuli grow twelve to twenty centimeters during the first five years of life, and then grow between two to four centimeters per year thereafter. Total length of the horns may reach 120 cm. The horns on an individual may have shorter annuli because of physical hardships during periods of drought or disease. The horn length in females reaches around 35 cm. (Gross, Alkon, and Demment, 1995; Mendelssohn, 1990; Nowak, 1990)

The oldest known individual of Capra nubiana lived 17 years in captivity. It is thought, however, that wild animals have much shorter life spans. Capra ibex, a related species, has been reported to live 10 to 16 years in the wild. (Jordan, 1969; Mendelssohn, 1990)

Nubian ibex are most active in the twilight period, resting and ruminating occurs in the afternoon or at night. During the winter months, Nubian ibex will seek shelter such as rock outcroppings or caves to avoid the cold, wind, or rain. They often hollow out shallow depressions in the ground in which to rest. Along the shores of the Dead Sea and on the Arabian Peninsula, temperatures may exceed 38 degrees Celsius. During warm periods like these, Nubian ibex will often lie down or occasionally turn on their sides to stay cool. They often spend the hot periods of the day in shaded areas. (Kingdon, 1997; Mendelssohn, 1990)

Home Range

Most groups have ranges of only a few square kilometers, dominated by either females or males which will fight other encroaching members of the same sex. Males are the dispersing sex, and it has been shown that females within a group are highly related to one another. Groups are sexually separated in part due to the need to separate feeding areas for nutritional demands and to find water sources. (Gross, Alkon, and Demment, 1995; Kingdon, 1997; Levy and Bernadsky, 1991)

Goats and ibexes are considered relatively non-vocal, but they have evolved a complex system of visual signals for aggression. Courtship displays are the most intensively studied component of communication in caprines, and are largely similar across all members of this groups. Males will display to other males with their horns, body movements, tongue or lips. They will also display to females. Females often bleat during estrus, and males may make several clicking, nasal sounds, or bleats. The rump patch is shown when animals are indicating submissiveness. (Fraser, 1986; Schaller, 1977)

During the rut, males will attempt to gain access to females by sniffing them, licking their anal areas, or nuzzling. If a female urinates, the male will then sniff her carefully, often curling his upper lip, which is a posture known as flehmen that further opens his olfactory senses. Non-receptive females will refrain from urinating, and simply continue grazing or occasionally run away. (Fraser, 1986; Schaller, 1977)

Horns are used for fighting, specifically for ramming rather than puncturing. Typically two males will spar, clashing their horns together to establish dominance. Occasionally females will also use their horns for aggression towards upstart young males or other females. Sparring between individuals seldom results in serious damage or bodily injury. (Fraser, 1986; Schaller, 1977)

Due to heat and water constraints, Nubian ibex usually feed during the night or twilight hours, and occasionally during the day. They descend to lower elevations to feed. The main diet includes herbs, shrubs, tree foliage (especially Acacia), buds, fruits, and occasionally grass. Nubian ibex especially prefer cadaba (Cadaba spp.) and camphorweed (Pluchea spp.). Nubian ibex forage in patches of high quality and where water is in close proximity. They drink water every day if available. (Hochman and Kotler, 2006; Kingdon, 1997)

Probable predators of Nubian ibex include leopards (Panthera pardus), wolves (Canis lupus), striped hyenas (Hyaena hyaena) and humans. Young ibex may also be preyed on by golden eagles (Aquila chrysaetos) and eagle owls (Bubo bubo). Proximity to cliff edges directly reduces the risk of predation, and Nubian ibex therefore spends much of their time on rock faces. The risk of predation for adult males is low; hence they may live in smaller group sizes. (Gross, Alkon, and Demment, 1995; Hochman and Kotler, 2006; Levy and Bernadsky, 1991; Shkedy and Saltz, 2000)

Caprinae as a group is catholic in their diet, exhibiting a large range of foraging niches, with a generalized and adaptive diet. They often live in habitats with low primary productivity. Nubian ibex are expanding specialist feeders, meaning individuals forage selectively on plants of higher quality in large patches, and hence increase herbivory on all the plants in the patch.

Grackles (Quiscalus sp.) have been known to groom Nubian ibex in a reciprocally beneficial act. They eat insects and parasites on skin of the ibexes. (Hochman and Kotler, 2006; Schaller, 1977; Yosef and Yosef, 1991)

Nubian ibex are likely to compete with domesticated goats (Capra hircus) and camels (Camelus dromedarius) as well as other herd animals for food and habitat. Foraging ibex in Israel have been recorded damaging orchards and other crops. (Hochman and Kotler, 2006; Shackleton, 1997)

Nubian ibex have been hunted for meat and trophies, and even used as an offering during the Dynastic period in Egypt. Hunting is now illegal in most of the countries in which C. nubiana occurs. However, poaching is still widespread and protected areas are poorly enforced. Nubian ibex have been extirpated in Syria and Lebanon due to over-hunting. Ziswiller 1967 (as cited by Osborn 1998) lists several folk uses from nearly every part of the ibex for humans. Folk uses include the blood for gall stone easement, the heel bone for diseases of the spleen, feces for anemia, the heart for strength, and stomach fluids for many healthful properties. (Osborn and Osbornová, 1998; Shackleton, 1997)

Capra nubiana is listed as an endangered species with an EN C2a classification on the IUCN Red List of Threatened Species. EN means endangered, and C2a means that the the population estimate is less than 2,500 mature individuals, with no subpopulations greater then 250 mature individuals and an overall declining population trend. Nubian ibex are not listed by the Convention on International Trade in Endangered Species (CITES) or the United States Fish and Wildlife Service (USFWS). Nubian ibex are protected in Israel, Jordan, and Oman. The population is thought to be at carrying capacity in Israel, but otherwise critically endangered in other areas. Threats to C. nubiana include habitat loss (via agriculture, livestock, and infrastructure development), hunting, pollution, and competition with non-native species. Protecting corridors which connect populations is particularly important for preventing population bottlenecks in this species. (Shackleton, 1997; Shkedy and Saltz, 2000)

Capra nubiana was first described by F. Cuvier in 1825 as a subspecies of Capra ibex, and synonyms for the species include C. arabica, C. beden, C. mengesi, and C. sinaitica. In 1987 C. nubiana was formally recognized as a distinct species.

In biomes with rich, lush habitats, caprines are typically replaced by cervids and larger bovids. In Africa, gazelles dominate the drier open steppes and grasslands. Thus Caprinae species have adapted to life in difficult environments. In a recent controversial study by Ropiquetet al. (2006), it was proposed that the common ancestor of wild goats arose from interspecific hybridization between ancestral goats (proto-Capra) and ancestral tahr (proto-Hemitragus). The product was a goat with a mitochondrial genome better adapted to high altitudes and with more efficient mitochondria, thus allowing them a special advantage to life in the mountains. (Grubb, 1993; Kingdon, 1982; Mendelssohn, 1990; Ropiquet and Hassanin, 2006; Uerpmann, 1987)

Despite their endangered status and elusive nature, Capra nubiana populations have become major tourist attractions in several areas. At the oasis of Engedi, on the Dead Sea, a certain subpopulation has become rather accustomed to humans, and males often predictably venture to a special watering hole popular with tourists. (Kingdon, 1982; Mendelssohn, 1990)