Bovids III: Gazelles, springboks, and saiga antelopes

(Antilopinae)

Class Mammalia

Order Artiodactyla

Suborder Ruminantia

Family Bovidae

Subfamily Antilopinae

Thumbnail description
Small-to medium-sized, slender-limbed and thin-necked herbivores characterized by a back that is straight or slightly higher at the croup, a pair of horns always present in males and sometimes present in females, narrow crowns of the molars, a hairy muzzle, many skin glands throughout the body, a four-chambered stomach, and a similar body color in the two sexes

Size
Head and body length of 2.8–5.6 ft (85–170 cm), tail length of 2.4–13.8 in (6–35 cm), shoulder height of 1.8–2.8 ft (54–84 cm), horn length (when present) of 3–19 in (8–48 cm), and weight of 26–128 lb (12–58 kg)

Number of genera, species
7 genera; 20 species

Habitat
Woodlands, plains, steppes, deserts, and other similar areas

Conservation status
Critically Endangered: 2 species; Endangered: 3 species; Vulnerable: 6 species; Lower Risk/Conservation Dependent: 6 species; Lower Risk/Near Threatened: 3 species

Distribution
Africa and Asia

Evolution and systematics

Antilopinae evolved from its family Bovidae, which is recognized to have a geological range of early Miocene (24 million to 5 million years ago [mya]) to Recent in Europe and Africa, middle Miocene to Recent in Asia, and Pleistocene to Recent in North America. A rapid diversification of the family into genus and species occurred possibly due to the formation of savannah habitat in Africa. The Antilopinae lineage was present by about 16–17 mya based on molecular genetic evidence. They were forced from the northern parts of Europe and Asia in the Pleistocene (which started about 1.6 mya) to their present locations in Africa and Asia, but did not cross over to North America except for the saiga antelope (Saiga tatarica), which did not survive in North America.

Physical characteristics

Antilopinae are long-legged, slender, and graceful animals with fawn-colored to reddish brown upper parts and pale undersides. Stripes can often occur at various locations around the body. Their tail is short or medium in length. Pits are present in the forehead of the skull, with narrow crowns on the molar teeth. On the rather small face, they have glands below their rather large eyes, with other skin glands throughout the body and a narrow, hairy muzzle. The indented preorbital glands are well developed. All males and many females grow short-to medium-sized horns (they are shorter and thinner in females when present) that vary greatly in size and shape (often lyre-shaped, or like a "U," but sometimes spiral-shaped, or like a "S") but the basic structure is always one of being: compressed at the base; attached to the frontal bones of the skull; single bony protrusions without branches; covered in a sheath of keratin; never shed; and ringed for part or most of their length. They are very fast on their feet and some species have been clocked at maximum speeds of nearly 60 mph (100 kph). Two-toed lateral hooves are at the ends of their very slender legs. They all have a four-chambered stomach, which allows most of them to digest foods that are too low in nutrients for many other animals, notably grasses.

Distribution

Antilopinae range throughout Africa and across the Middle East and into Asia.

Habitat

Antilopinae live in a variety of habitats from open woodlands and grassy plains to short grass steppes and steppes with trees and dense bush to barren high-altitude steppes, semi-deserts, and deserts.

Behavior

Antilopinae are generally gregarious animals but normally keep a certain distance apart from each other, and under certain circumstances will seek temporary isolation. In most cases, they form groups ranging from two to hundreds (and sometimes even thousands) of individuals. The differences in herd size depend on the environment, population density, season, and species. Herds generally are open, where members come and go freely. Most herds are classified as all-female, all-male (sometimes all-bachelor), or mixed (female/male). Only adult males become territorial, but not all of the adult males become territorial: only those who are successful with the mating of females. They are not territorial throughout their lives, alternating between non-territorial and territorial periods. Owners of territories, in some species, exclude other males from their territories, or at least dominate them within the territorial boundaries. Such owners also mark their territories with

secretions from the preorbital gland and with urine and feces. Females will periodically visit the males in their territories.

Feeding ecology and diet

Antilopinae are herbivorous, but a few will take a small amount of meat if it is available. Their diet consists of grasses, herbs, leaves, buds, and shoots. Water is acquired from moisture within and on their food, although most will drink when water is available.

Reproductive biology

Males and females are usually polygamous, and territorial males and females remain as separate and independent social units. When there are many neighboring territories, a male may guard an all-female herd while in his territory, but will change guardianship as different female herds enter and exit. Females normally give birth to one young at a time, but may give birth to more under ideal conditions. Births occur generally in tandem with the rainy season, when food is plentiful, and can occur throughout the year. Females isolate themselves from the herd before giving birth and remain solitary with her young immediately after the birth. Males have little or no parental activity toward the young.

Conservation status

According to the 2002 IUCN Red List of Threatened Species, Procapra przewalskii and Saiga tatarica are Critically Endangered; Gazella cuvieri, Gazella dama, and Gazella leptoceros are Endangered; Antilope cervicapra, Ammodorcas clarkei, Gazella dorcas, Gazella rufifrons, Gazella soemmerringii, and Gazella spekei are Vulnerable; Gazella bennettii, Gazella gazella, Gazella granti, Gazella thomsonii, Litocranius walleri, and Antidorcas marsupialis are Lower Risk/Conservation Dependent; and Gazella subgutturosa, Procapra gutturosa, and Procapra picticaudata are Lower Risk/Near Threatened.

These animals are threatened by overhunting, as well as by habitat loss and degradation from human activities.

Significance to humans

Antilopinae are hunted for their meat, skin, and sport.

Species accounts

List of Species

Dorcas gazelle

Gazella dorcas

taxonomy

Capra dorcas (Linnaeus, 1758), lower Egypt.

other common names

French: Gazelle dorcas.

physical characteristics

Dorcas gazelles have a head and body length of 3.0–3.6 ft (90–110 cm), tail length of 6–8 in (15–20 cm), shoulder height of 1.8–2.1 ft (55–65 cm), and weight of 27–44 lb (12–20 kg). They are considered one of the smallest of the gazelles, but proportionately are the longest limbed. Their slender limbs contain splayed hooves. They can reach running speeds of 60 mph (95 kph) and can maintain steady speeds of 30 mph (48 kph). Dorcas gazelles have long ears. Across their nose is a fold of skin that can be inflated and vibrated when they feel threatened, thus generating a sound like the quacking of a duck. The upper coat is colored pale beige or sandy-red, while the undersides and rump are white. A wide, sometimes indistinct, rufous stripe runs along the lower flank between the front and rear legs; the stripe separates the white belly from the upper coat. Another similarly colored strip is located on the upper hind legs, creating a border for the white rump. The head is the same beige color as the body. There is a white ring around each eye, and a pair of white and dark brown streaks running from each eye to the corners of the mouth. The forehead and bridge of the nose are generally light reddish tan in color.

Strongly ridged, lyre-shaped (pointed outward and then coming in at the tips) horns are found in both sexes, but those of the females are smaller and more slender. They may have up to 25 annular rings on their horns. In males they are bent sharply backwards, and curve upwards at the tips, growing

10.0–15.2 in (25–38 cm) long. The horns of the females are much thinner and straighter, with fewer ridges, and a length of 6–10 in (15–25 cm).

distribution

Morocco south to Mauritania (and formerly to Senegal) east to southern Israel and Egypt and from there south to Sudan, northeastern Ethiopia, and northern Somalia.

habitat

They live in savannas, dry hills, sub-deserts, and true deserts; but prefer stony deserts to rocky deserts and avoid steep terrain. They live primarily on the perimeter of the Sahara, but it is not uncommon for them to venture further into the desert.

behavior

Dorcas gazelles are well suited to desert climates. They may go their entire lives without drinking water, obtaining necessary moisture from plants that they eat. Being well adapted to dry climates, they produce very concentrated urine during dry weather. They are usually active, especially during hot weather, only at dawn, dusk, and throughout the night. However, they can withstand very hot temperatures, if necessary. Animals will migrate and run in herds over large areas in search for food. Herds tend to consist either of single-sex animals with up to 40 animals or mixed herds of up to 100. When not foraging for food, groups usually only reach about 12 in number, with one adult male. In order to defend against predators, groups of 2–5 males sometimes form. They tend to congregate in areas where recent rainfall has stimulated plant growth, and may also associate with other gazelles and camels.

Adult males are territorial, establishing piles of dung throughout their range in a conspicuous display in which the male will first paw at the ground, then stretch over the scraped area and urinate, and finally crouch with his anus just above the ground, at which time he deposits his dung. Males defend small territories during the breeding season or, sometimes when times are good, for the entire year. The preorbital glands, although functional, are not used for marking. Its call of alarm when sensing danger, which sounds like a duck's quack, is made through the nose, which inflates during the process.

feeding ecology and diet

Dorcas gazelles eat grasses, shoots, leaves (especially the pods of acacia trees), blossoms, and succulents. They also browse the green leaves of some bushes and dig up bulbs of perennial plants. Often they will stand on their hind legs to reach leaves high off the ground. They will occasionally eat invertebrates.

reproductive biology

Polygamous. Mating season is December to November in the wild. In areas where agriculture (or nature) has led to below normal amounts of available water, they may breed at other times of the year. Female gestation period is 164–174 days, with usually one baby born (on rare occasions two are born). Newborns weigh 2.2–4.0 lb (1.0–1.8 kg). After birthing, mothers will hide their young for 2–6 weeks. Mothers will induce defecation in nursing young and ingest the feces (which is thought to be a water conservation adaptation). They are weaned after 2–3 months; become sexually mature at 9–12 months for females and at 18 months for males; and have a life span of up to 12.5 years in the wild and up to 17 years in captivity.

conservation status

Vulnerable. According to IUCN, their population trends are drastically declining primarily due to overhunting. Predators include the common jackal, cheetah, lion, leopard, serval cat, desert lynx, wolf, striped hyena, vulture, and eagle. Smaller cats, honey badgers, jackals, and foxes eat fawns. They are particularly vulnerable when they migrate in large numbers.

significance to humans

They are hunted for their meat and skins. They help to keep vegetation from becoming overgrown.

Thomson's gazelle

Gazella thomsonii

taxonomy

Gazella thomsonii Günther, 1884, Kilimanjaro, Kenya.

other common names

English: Tommies.

physical characteristics

Thomson's gazelles have a head and body length of 3–4 ft (91–122 cm), tail length of 6–8 in (15–20 cm), and weight of 29–66 lb (13–30 kg). Males have a shoulder height of 23–28 in (58–70 cm), and a weight of 37–66 lb (17–30 kg), while females have a shoulder height of 23–35 in (58–64 cm), and a weight of 29–53 lb (13–24 kg). They have a light reddish brown coat on top, a white belly, a fawn colored stripe underneath, a distinctive black stripe running from the foreleg to the hindquarters, and a white rump patch that extends to the entirely black tail. The uniquely dark side stripes may serve as visual signals to keep the herd together. They have pronounced facial markings. The eyes are rimmed with a white line, which then extends to the nose along the muzzle and above black cheek stripes. A dark finger-like pattern occurs on the inside of the ears. Their sight and sense of hearing are well developed, which lets them scout out a large area. Their dark parallel horns are long and only slightly curved. Males have robust, curved horns with large ridges (rings) encircling them. They can reach 11.5–12.0 in (29.2–30.5 cm) in length and are used exclusively for intra-species fighting. Female horns are shorter and more slender; and are used in order to defend their feeding area, especially when food resources are limited. Because of this excess use of their horns, females often end up with broken or deformed horns, or without horns. They have facial and leg glands for territorial marking and species recognition. This species is the least drought tolerant of all the gazelles.

distribution

Southern and central Kenya, southwestern Ethiopia, northern Tanzania, and southeast Sudan.

habitat

They stay primarily in the short grassy plains and savannas where food is most abundant and where the landscape is open enough to allow for the gathering of large herds. They feed and reproduce on the short-grass plains during the rainy season and in the taller grasslands in the drier season.

behavior

Thomson's gazelles are both nocturnal and diurnal, but are most active early and late in the day, preferring to rest during the hottest part of the day. They are primarily silent animals. Their primary defense against predators is to run, which they can do very effectively at speeds of 40–50 mph (65–80 kph). They can gracefully leap 10 ft (3 m) into the air, jump 30 ft (9 m) in a single leap, and make turns much faster than can a cheetah, one of its main predators. Thomson's gazelles engage in gaits called "stotting" or "pronking" when playing or alarmed. This action entails bouncing stiff-legged so that all four legs land on the ground together. It is believed that this activity helps them to communicate alarm to each other, to give them a better view of approaching predators, and even to confuse or intimidate predators. They have elongated foot bones and anklebones that gives them their speed. They live in herds up to 200 members but normally associate in groups of 2–20. These groups are loosely based, and can change by the hour. They often migrate in groups numbering in the thousands. Multiple groups are often seen interacting with each other. Territories can range from 6 to 495 acres (2–200 ha) but normally are 25–75 acres (10–30 ha). They are very water-dependent but can become water-independent when necessary. During dry periods, they need to be near a water source, sometimes travelling as much as 100 mi (160 km) to find one. During the breeding season males establish territories in order to secure mating rights with females. Males mark their territories with urine and dung piles, and also with secretions from their pre-orbital glands. Territorial males will tolerate familiar subordinate males in their territories as long as they remain subordinate and do not approach the females. Nonbreeding males form bachelor herds.

feeding ecology and diet

Thomson's gazelles graze on short grasses, alfalfa hay, and leaves. They avoid tall grass areas. Almost all of their diet consists of grasses. They get most of the water they need from the grasses they eat.

reproductive biology

Polygamous. Thomson's gazelles generally breeds twice a year in parallel with the coming rainy season in late December/early February (short rains) and late June/July (long rains), but reproduction is also dependent on the health of the female and environmental conditions. Females give birth to one baby after a gestation period of 5–6 months. The young coat is mottled darker than the mother's coat, but lightens within 1–2 weeks. Females isolate themselves during the birth of their young in order to strength the fawn, and will remain separated from the herd for the first few weeks of life. Once the offspring can run well enough (within 3–4 weeks), mother and fawn will rejoin the group. The weaning period lasts about four months. Females can become impregnated 2–4 weeks after giving birth. Lifespan in the wild is 10–20 years.

conservation status

Lower Risk/Conservation Dependent. Predation on this small gazelle is always high; they are preyed upon primarily by cheetahs, but also by lions, hyenas, wild dogs, jackals, honey badgers, crocodiles, and leopards. Smaller predators such as pythons, serval cats, baboons, and birds of prey (such as eagles) will also eat the young. Despite the large numbers and types of predators, Thomson's gazelles can be found in numbers of up to 500,000 in Africa, the most common of the gazelles in east Africa.

significance to humans

They are hunted for food and skins.

Springbok

Antidorcas marsupialis

taxonomy

Antilope marsupialus (Zimmermann, 1780), Cape of Good Hope, South Africa.

other common names

English: Springbuck.

physical characteristics

Springboks have a head and body length of 4.0–4.6 ft (120–140 cm), tail length of 7.5–10.8 in (19.0–27.5 cm), shoulder height of 2.4–2.9 ft (73–87 cm), and weight of 70–100 lb (32–45 kg). A dark reddish brown horizontal band along its flanks divides the cinnamon-fawn upper parts from the white underside, back of the thighs, inside of the legs, and the tail. Their hindquarters also appear to be slightly higher than the shoulders. They have white coloration on their face and muzzle, with a dark reddish brown stripe running through the eyes down to the corner of the mouth. The stripes turn to a darker shade and eventually to white on the lower third of the body. Their backside is white. Both sexes have medium-long, lyre-shaped, curved, black horns with bulges across them, although mature males have distinctly thicker and longer ones, growing as much as 14–19 in (36–48 cm) long. They are generally distinct from other gazelle species with respect to their teeth. Springboks have five pairs of grinding teeth in their lower jaws, two premolars, and three molars, while other gazelles have six pairs of grinding teeth in all. Another species difference is the fold of skin extending along the middle of the back to the base of the tail. This fold is covered with hair, much lighter in color than the rest of the back. When alarmed by possible predators, they open and raise this fold so that white hair is conspicuously displayed as a crest along the back. While showing this fold, white hairs on the rump are erected and the animal frequently leaps high.

distribution

Originally found in Namibia, southwestern Angola, Botswana, and South Africa, but range has been drastically reduced.

habitat

Springboks prefer open, arid plains, savannas, and grasslands that occur in the arid western areas of the southern African subregion.

behavior

Springboks are highly gregarious, being active during the cooler times of the day and partially active at night. When springboks sense danger they repeatedly "spring" up (hence their name) to 9.8–11.5 ft (3.0–3.5 m) into the air with their front and hind legs close together and stiff; hooves bunched; backs arched and showing off their broad, white crests; and their heads straight, in a display called "pronking." They then hit the ground and rebound with apparently little effort. This action often results in other springboks responding with the same efforts. The leaps are used primarily to distract predators. Also when in fear for their safety, springboks will let out a high-pitched alarm. They normally congregate in small mixed or ram (male) herds, but can occasionally be seen in herds of several thousands when moving to new feeding grounds. During drier months they divide into smaller groups of up to 100 females and young, each associated with a number of adult males. Non-territorial solitary males form bachelor herds of up to 50 individuals. They are territorial, especially when they gather up female groups during the rutting season. They do not, however, remain in their territories throughout the year.

feeding ecology and diet

They graze and browse both on grass and flowers/shrubs (especially karroo shrubs), often switching from one to the other depending on the season. They are fairly independent of the water supply, being able to switch to flowers (which have double the mean water content from that of grasses) when less water is available. They can survive long periods of time without drinking water, but will drink it when available, because they obtain sufficient water from the succulent leaves they select. They will also dig up succulent roots.

reproductive biology

Polygamous. Males that are younger, older, or injured (or with other problems) wander together in search of mates, but are of lower status with regards to reproduction. Dominant males and females with their earlier offspring remain in herds during the mating season. Springboks generally mate during the dry season and lactate during the hot, wet season when resources are most abundant. Births usually occur from October to December, at the start of the wet season. Gestation period is 4–6 months (averaging 171 days), and females generally reproduce every two years, starting between the ages of 1–2. Each female gives birth to a single young. Weaning usually occurs from 6–12 months. Parental contribution is primarily by the mother. They have a lifespan of about 7–10 years.

conservation status

Lower Risk/Conservation Dependent. Natural disasters and ongoing drought, along with pathogens and parasites, continue to threaten the animals.

significance to humans

Springboks are hunted for their meat. They can inflict enormous damage onto cultivated crops when their large-numbered groups migrate.

Saiga antelope

Saiga tatarica

taxonomy

Capra tatarica (Linnaeus, 1766), "Ural Steppes," western Kazakhstan.

other common names

English: Saiga; French: Saïga.

physical characteristics

Saiga antelopes have a head and body length of 3.3–5.6 ft (100–170 cm), tail length of 2.4–5.2 in (6–13 cm), shoulder height of 2.0–2.6 ft (60–80 cm), and weight of 66–152 lb (30–69 kg). Their most distinctive feature is a large head with a bulging shape and with a huge, inflatable humped nose that hangs over its mouth and with downward-pointing nostrils. This fleshy nose has a unique internal structure, with convoluted bones, mucoussecreting glands, and many hairs. The large nose is believed to filter out airborne dust during summer migrations and to heat the cold air before getting to the lungs during winters. The eyes appear to stand out on small, bony protrusions when viewed straight on. Their senses of hearing and smell are poorly developed, but their eyesight is acute, and they are able see danger up to 0.6 mi (1 km) away. Males possess a pair of long, semi-translucent, waxy colored horns with ring-like ridges along their lower two-thirds of length, which grow 8–10 in (20–25 cm)

long. Except for their unusually large snout and horns, they resemble small sheep. They have long, spindly legs that support a slightly robust body. The hooves are slightly broader at the rear. During summer months, they have a cinnamon-buff to yellowish red back and neck with a paler underside. The summer coat is short and almost smooth. In the winter, the coat becomes denser and longer, and it turns a muted gray to almost a white color on the back and neck and a light brownish gray shade on the underside. The winter coat, looking wool-like, may be up to twice as long and 70% thicker than the summer coat. A course set of bristly hairs protects them from the harsh weather. They have a very short tail that is always light in color. There is a small mane on the underside of the neck.

distribution

Northern Caucasus, Kazakhstan, northern Uzbekistan, southwestern Mongolia, and Singkiang, China.

habitat

Dry steppes and semideserts. Herds are found primarily on flat, open areas (such as plains) covered with low growing vegetation (such as grasses) that do not contain rugged terrain and hills. They generally do not move more than about 2–4 mi (3–6 km) per hour while grazing. But, may move 75–125 mi (120–200 km) within two days when severe frost cuts off their food supplies.

behavior

Saiga antelopes are a very timid and easily startled species, which can cause immediate flights for safety. They are a polygamous species. During the breeding season they congregate into groups consisting of 5–10 females and one male. Males are very protective of their harem of females, with violent fights often breaking out (and sometimes leading to death) between males. Because males do not feed during the mating season, rather they spend most of their time defending their harem; they grow very weak near the end of the breeding season. As a consequence, male mortality often reaches 80–90%. At the end of breeding season, herds will form consisting of 30–40 individuals, but will form again at the beginning of next year's breeding season. They are a nomadic herding species, migrating as a group for food, and in order to escape such weather as snowstorms and droughts. Seasonal migrations move north in the spring to the summer grazing grounds, and return southward in the fall. Spring migrations may include 200,000 individuals in a herd, while summer groups have only 30–40 members. They have no fixed home range, and usually walk 48–72 mi (80–120 km) in a day. When they march, their heads are often kept low to the ground. They tend to avoid areas of broken terrain or dense cover because such ground is not conducive to fast running. They are very good runners, and are able to reach speeds up to 48 mph (80 kph). During the day, they graze and visit watering holes, but may rest during midday. Before night they dig a small round depression in the ground that serves as their bed.

feeding ecology and diet

Saiga antelopes are herbivores, grazing on over 100 different plant species; however, the most important are grasses, herbs, prostrate summer cypress, saltworts, fobs, sagebrush, steppe lichens, and other plants containing salt. They will often eat plants that contain poisonous substances, which are not eaten by other animals. They will visit watering holes about twice a day when moist plants are not available.

reproductive biology

Polygamous. They have a high rate of reproduction where in a favorable season they may grow in population up to 60% in a single year. The rutting season begins in the wintering grounds, when males become territorial in an attempt to gain a harem of usually 5–25 females. During the mating season, which only lasts 6–7 days, males will only eat snow, using most of its time to defend its harem from lurking males. Females reach sexual maturity at 7–8 months, while males reach sexual maturity at 20–24 months. The breeding period lasts from late November to late December, with births occurring from the end of March to May. The gestation period is about 140–150 days, and usually gives birth to two, sometimes three, young after the first year (in which only one is normally born). Mothers usually drop their calves within a few days of each other. Newborns will lie concealed and immobile for the first three days, and then will begin to graze at 4–8 days old on bits of green food. The lactation period lasts for about four months, and the weaning period is 3–4 months. Very few animals live beyond 3.5 years of age, but known lifespan in the wild is 6–12 years, with males especially susceptible to death after fasting during the mating season, just before the cold winter season.

conservation status

Critically Endangered. They are threatened from increased habitat loss and degradation primarily from human disturbances, along with the continuing presence of illegal hunting for meat and male horns (for medicinal properties). Their most dangerous predators are wolves, foxes, and birds of prey.

significance to humans

They are hunted for their fur, meat, and horns. The horns are considered as their most valuable feature. Horns are ground up and used in Chinese medicines to reduce fevers. They occasionally destroy agricultural plants and feed on crops.

Mongolian gazelle

Procapra gutturosa

taxonomy

Procapra gutturosa (Pallas, 1777), southeastern Transbaikalia, Russia.

other common names

None known.

physical characteristics

Mongolian gazelles have a head and body length of 3.3–5.0 ft (100–150 cm), tail length of 3.2–4.8 in (8–12 cm), shoulder height of 1.8–2.8 ft (54–84 cm), and weight of 44–86 lb (20–39 kg). They seldom make a sound, but occasionally will make loud bellows during the rutting season. Their coat is colored a light brown or buff that has orange-buff tones with pinkish cinnamon sides in the summer; the hairs become longer, each hair going up to 2 in (5 cm) in length, and paler in winter. The darker upper coat gradually converts into the white under parts, while the heart-shaped patch of white hair on the rump is very distinctive. The muzzle, chin, and jowls are white, while the bridge of the nose may be slightly darker than the body color. During the breeding season, males develop a swollen throat, and may also get a "bulbous" muzzle. Their eyes are small, but they protrude noticeably from the head. Only males possess horns that are dark gray and lyreshaped horns, curling backward from the forehead and then running parallel to the back. Slightly ridged along most of their length, the horns grow 10–16 in (26–40 cm) long and diverge along their length, such that the tips are 6–10 times farther apart than at the base.

distribution

Eastern Mongolia and Inner Mongolia, China.

habitat

Grassy steppes and sub-deserts.

behavior

Mongolian gazelles are active during the daylight hours of fall and winter, mostly grazing in the mornings and late afternoons. They will excavate a depression bed within bushes in order to shelter themselves from winds and harsh weather. Being very fast animals, they are able to run up to 40 mph (65 kph), sustain this speed for 7–9 mi (12–15 km), and can leap up to 6.6 ft (2 m) into the air. They also are good swimmers, and can easily cross wide rivers. Large-scale migrations are regularly taken by this species. Herds of 6,000–8,000 animals of both sexes gather in the spring where they begin their northerly migrations for food and to drop young, often covering 120–180 mi (200–300 km) in a day. When reaching summer pastures in June, the sexes will isolate themselves and females prepare to give birth. Herds generally use several hundred square miles (kilometers) as their summer home range, regularly shifting areas in the search for food. During the winter, herds normally number no more than 120 animals. Sometimes single-sex herds of 20–30 animals will gather.

feeding ecology and diet

They eat grasses and herbs.

reproductive biology

Polygamous. The mating season is from November to January, with resulting births from May to July. Mating occurs within the herds, and males actively collect harems. Female gestation period is about 185 days, with usually 1–2 births per pregnancy (twins are common), although three births sometimes occur. Mothers will hide her young for their first days of life, but will later join the herds after 4–8 days. Herds tend to be small during this time. Young are weaned after about five months, sexual maturity occurs at 1.5–2.0 years, and life span is around seven years.

conservation status

Lower Risk/Near Threatened. Humans primarily threaten them from habitat loss and degradation, and ongoing hunting. Their primary enemy is the wolf, but lynxes and dogs also prey on them. Foxes, cats, and eagles may take the young.

significance to humans

They are hunted for their meat and skin.

Mountain gazelle

Gazella gazella

subfamily

Antilopinae

taxonomy

Gazella gazella (Pallas, 1766), Syria.

other common names

French: Edmi.

physical characteristics

Mountain gazelles have a head and body length of 3.1–3.4 ft (95–105 cm), shoulder height of 2.0–2.6 ft (60–80 cm), tail length of 5.9–7.9 in (15–20 cm), and weight of 33–77 lb (15–35 kg). Males have a weight of 38–77 lb (17–35 kg), while females have a weight of 33–55 lb (15–25 kg). They have a slender build with proportional looking long necks and legs and exceptionally long hind legs. The coat is a dark brown in color, with white on the under parts and the backs of the legs. The coat is short and sleek during the summer months (in order to reflect the sun's rays) and is longer, thicker, and rainproof during the winter months (in order to protect it from the heavy rains). A narrow, dark flank band separates the dark dorsal tones from the white belly. A white line begins on the thigh and ends at the lower leg joint. The base of the hairs from the underside is buff colored, while the black tail is short and bushy. Both males and females have two elliptical (in cross-section) horns that are arched backwards, generally S-shaped, and separated by about 1 in (25 mm). Horns are used primarily for defense against predators (for example, butting small enemies). Male horns are 9–12 in (22–29 cm) long, thick and ringed, of different lengths depending on the habitat, and bowed out from the base with the tips almost always pointing in. Female horns are 3–6 in (8–15 cm) long, curved slightly forward, slender, and not ringed. Facial markings include numerous shades of brown throughout the face and two white stripes beginning from the eyes and ending near the nostrils. They have well-developed vision, along with good hearing and smell. Vision is the primary sense used for predator detection, whereas smell is used mainly for finding food. They have a large snout and tooth rows are nearly straight. The ears are relatively short.

distribution

Arabian Peninsula, Egypt, Iran, Israel, Jordan, Lebanon, Oman, Saudi Arabia, Syrian Arab Republic, Yemen, and the United Arab Emirates.

habitat

They are found in a wide variety of habitats in hilly and mountainous terrain, including light forests (especially oak and pine), fields, grasslands, and stony desert plateaus.

behavior

Mountain gazelles are diurnal and highly territorial. Their territories are widely spaced apart. They generally gather in three groups: maternity herds, bachelor male herds, and territorial solitary males. Fights occur more frequently as males mature,

however fights between neighboring males are ritualized and less violent than when males fight over females. Immature bachelor males make more numerous contacts with their horn when fighting than do adult or territorial males. They regularly migrate over 75 mi (120 km) for food. Normally they will spend days resting and sleeping in hilly areas, and later will descend to valleys in order to feed at nights or in early mornings. They can run at high speeds for several hundred feet (meters), reaching speeds up to 50 mph (80 kph).

feeding ecology and diet

They are browsers and grazers, eating herbs and shrubs in the summer and green grasses in the winter. They are well adapted to living in harsh desert climates, being able to go without water for long periods of time. They utilize water from plants as well as dew, but also will visit waterholes on a frequent basis.

reproductive biology

Polygymous. Males attend to one or more females and their young generally in groups of 3–8. Estrous occurs every 18 days and lasts 12–24 hours, repeating until the female becomes pregnant. Males and females reproduce with various partners. Females usually give birth to one baby per season (and, on average, 11 in her lifetime). The usual mating season is in early winter (October to November), although mating also occurs in the spring (April to mid-May) and at other times when food is plentiful. The gestation period is about 180 days. Newborns generally weigh about 11–12% of the mother's weight. Mothers give birth away from the herd. The newborn can stand shortly after birth, and spends the first few weeks nursing. They begin to take solid food when they are 3–6 weeks old, but suckling may last up to three months. Males do not contribute to the care of the young. At this time, mother and young will join a maternity herd. Female young will remain with the mother, but male young will leave the mother at about six months, joining a herd of young males. Females reach sexual maturity (and their adult weight) at about 18 months, while males reach this stage at about 3 years. They rarely live longer than eight years in the wild, but in captivity can live 12–15 years.

conservation status

Lower Risk/Conservation Dependent. They are regularly threatened with human-induced habitat loss and degradation from increased amounts of pastureland for livestock and deforestation for agriculture and home building, along with invasive alien species and ongoing hunting by humans. Their primary predators are the cheetah and human, but are also sought after by the desert lynx, feral dog, hyena, jackal, leopard, red fox, and wolf. Predators do not (normally) affect their populations, except in the case of humans.

significance to humans

They are hunted for skins, meat, and as trophies and often eat the cultivated crops within their habitat.

Gerenuk

Litocranius walleri

subfamily

Antilopinae

taxonomy

Gazella walleri (Brooke, 1879), Somalia.

other common names

English: Giraffe gazelle, gugufto, nanjaat, Waller's gazelle.

physical characteristics

Gerenuks have a head and body length of 4.6–5.2 ft (140–160 cm), tail length of 8.7–13.8 in (22–35 cm), shoulder height of 3.0–3.3 ft (90–100 cm), and weight of 64–128 lb (29–58 kg). Males and females possess a similar shape, but males are more muscular so weigh more than females. They have long necks and long, slender legs, both which are their most defining features. The giraffe-like neck is only 7–10 in (180–255 mm) in circumference. Their coat contains short, fine, glossy hair that is evenly distributed throughout the body, and is colored a pale tawny brown with white along the breast, underbelly, and inner legs. There are small, dark patches of fur on the knees of the forelegs and at the end of the tail. The long, narrow head contains medium-sized ears, with reduced cheek teeth and chewing (masseter) muscle. There is a narrow muzzle with very flexible lips; the long upper lip and long tongue both help to pluck high-reaching leaves off of trees. The dark patch around the eyes becomes paler as it goes outward until it forms a white rim. Only males have horns, which are scimitar shaped; relatively massive; curved backward, upward, and hooked forward near the ends; and of length 9.8–17.3 in (25–44 cm).

distribution

Eastern Ethiopia, Somalia, Kenya, northeastern Tanzania.

habitat

Their habitat varies from treeless plains (in southern portions of the range) to dry high deserts (in northern portions). They are well adaptable and do well in a variety of habitats as long as there is an ample supply of succulent plants.

behavior

Gerenuks are primarily active during the day. Males are solitary and very territorial, only associating with females during the mating season or when they are young. Dominant males establish territories by marking shrubs and trees with their preorbital gland. A male inside his own territory will not force off other dominant males, but will show aggression to young males who enter his domain. Male territories are 300–850 acres (120–345 ha) and can support several individuals. Females form small bands of up to about ten individuals, usually consisting of related female adults with young and roaming freely throughout male territories. Young males will often form bachelor herds that roam nomadically until they become mature enough to develop their own territories and to breed. They travel singly, in pairs, or in groups of 6–7 females led by a single male. Gerenuks will stand motionless, hiding behind bushes or trees, when predators approach, and then look over or around their cover by means of their long neck. When frightened, they leave in a stealthy, crouched trot with neck and tail carried horizontally. They are not fast animals, as compared to the other genera.

feeding ecology and diet

They are well adapted to foraging in arid habitats, usually alone. Their long necks and legs, and their ability to stand (even walk to a certain extent) on their hind legs, allow them to obtain tree leaves that are high off the ground and out of the reach of most other animals. It usually leans with its front legs against a tree trunk or a branch. They consume a select number of herbaceous plants, often numbering as many as 80 different plant species, including grasses, foliage, acacia leaves, and succulent plant parts. They do not drink standing water, but take in moisture within succulent plants that they eat.

reproductive biology

The mating ritual of gerenuks is complicated. Females will raise their nose into the air when seeing a potential male mate, and then pull her ears close to the head as a defensive sign. At the same time, males will display his horns and neck in a side-ways pose. If the male sees that the female is receptive, he will mark the female on the thigh with the contents of his preorbital gland and then follow her around in a stance of guarding her. He will repeatedly kick the female in her thigh region. When she attempts to urinate the male will perform (what is called) the "flehmen test" or "lip curl test" where he smells her urine. When the female comes into estrous the male will notice the difference in the urine and will begin mating. The polygamous males will perform this routine on several females. The gestation period is about 165 days. Females breed every 1–2 years, depending on the sex of their previous year's offspring, and will give birth to one young, rarely two. Reproduction occurs throughout the year, often depending on the quality and quantity of available food. Newborns begin to walk almost immediately after being born, and are able to eat tender leaflets. Young gerenuks will remain motionless in bushes and tall grasses while mothers are feeding to help hide from predators. The weaning period is 12–18 months. Male young sexually mature later than female young, with an average maturity period of 1–2 years. The average life span in the wild is 10–12 years, with females slightly outliving males.

conservation status

Lower Risk/Conservation Dependent. A wide range of predators, especially Cape hunting dogs, hyenas, leopards, lions, and cheetahs, preys upon gerenuks. Young are often preyed upon by desert lynxs, large eagles, honey badgers, and servals (African wild cats).

significance to humans

They are hunted for their meat and as trophies.

Resources

Books

Burnie, David, and Don E. Wilson, eds. Animal. Washington, DC: Smithsonian Institution, 2001.

Feldhamer, George A., Lee C. Drickamer, Stephen H. Vessey, and Joseph F. Merritt, eds. Mammalogy: Adaptation, Diversity, and Ecology. Boston: WCB McGraw-Hill, 1999.

Gould, Dr. Edwin, and Dr. George McKay, eds. Encyclopedia of Mammals. 2nd ed. San Diego, CA: Academic Press, 1998.

Grzimek, Bernard. Grzimek's Animal Life Encyclopedia. New York: Van Nostrand Reinhold Company, 1972.

Honacki, James H., Kenneth E. Kinman, and James W. Koeppl, eds. Mammal Species of the World: A Taxonomic and Geographic Reference. 2nd ed. Lawrence, KS: Allen Press and the Association of Systematics Collections, 1982.

Macdonald, David., ed. The Encyclopedia of Mammals. New York: Facts on File, 1984.

Martin, Robert Eugene. A Manual of Mammalogy: With Keys to Families of the World. 3rd ed. Boston: McGraw-Hill, 2001.

Nowak, Ronald M. Walker's Mammals of the World. Vol. 2, 6th ed. Baltimore and London: Johns Hopkins University Press, 1999.

Parker, Sybil P., ed. Grzimek's Encyclopedia of Mammals. Vol. 2. New York: McGraw-Hill Publishing Company, 1990.

Special Publications Division. (prepared by) National Geographic Book of Mammals. Washington, DC: National Geographic Society, 1981.

Walther, Fritz R., Elizabeth Cary Mungall, and Gerald A. Grau. Gazelles and Their Relatives: A Study in Territorial Behavior. Park Ridge, NJ: Noyes Publications, 1983.

Walker, Ernest P, et al. Mammals of the World. 2nd ed. (revision by John L. Paradiso). Baltimore: Johns Hopkins Press, 1968.

Whitfield, Dr. Philip. Macmillan Illustrated Animal Encyclopedia. New York: Macmillan Publishing Company, 1984.

Wilson, Don E., and DeeAnn M. Reeder, eds. Mammal Species of the World: A Taxonomic and Geographic Reference. 2nd ed. Washington, DC: Smithsonian Institution Press, 1993.

Vaughan, Terry A., James M. Ryan, Nicholas J. Czaplewski Mammalogy. 4th ed. Fort Worth, TX: Saunders, 2000.

Other

Animal Diversity Web. The University of Michigan Museum of Zoology. [June 20, 2003]. <http://animaldiversity.ummz.umich.edu>

Mammal Species of the World (MSW). Division of Mammals, Department of Systematic Biology (Vertebrate Zoology), Smithsonian National Museum of Natural History. [ June 20, 2003]. <http://www.nmnh.si.edu/msw>

The IUCN Species Survival Commission: 2002 IUCN Red List of Threatened Species. IUCN Species Survival Commission. [June 20, 2003]. <http://www.redlist.org>

William Arthur Atkins