Reproductive biology

Female bovids usually give birth to their first young when two or three years old, while most males, although capable of breeding around this same age, usually do not begin to fully participate in reproductive activities until older. Typically, females are interoparous, giving birth to one, sometimes two, young each year throughout their life. Males are usually semel-parous, spending their early years growing large bodies and weapons (hooves and horns), and concentrating their mating activity to a limited number of years toward the end of their life.

Births are usually timed to coincide with the beginning of the annual plant growth cycle, so that females can benefit from the nutritious forage for lactation, and the young have a long time to grow before the onset of more difficult conditions in their first winter or dry season.

Parental care

Only females provide parental care in the Bovidae. Adult males, for the most part, live separately, either alone or in groups with other males, and thus take no part in rearing young. Females may remain in the group to give birth or leave to seek a secluded area with dense cover as concealment against predators. Like other artiodactyls, the young may be hiders and followers in the first week or two of life, either remaining hidden during the day while the mother feeds elsewhere, or remaining near her.

Mating systems and courtship

The majority of bovids are polygynous, with a male mating with more than one female. Only some of the small species such as dik-diks and dwarf antelopes form pair bonds, with a male and female usually remaining together in a territory held year-round. The more common polygynous-mating systems are temporary, with a male defending one or several females at once against other males in order to mate with them. When a male defends a single female at a time, as in most caprins, this is called a tending pair. When the male defends a group of females, this is termed a harem. Males in several species also defend mating territories, which contain resources such as rich food patches and security from predators. These resources attract females so that the male can then attempt to keep them on his territory so he can court and mate with them. Usually, the territories with the best resources are held by the most dominant males. Owning a territory not only attracts females, the male often has the added benefit of being able to mate with less interfer-

A klipspringer (Oreotragus oreotragus) pair. (Photo by Harald Schütz. Reproduced by permission.)

ence. Examples of species holding mating territories include the various African gazelles (Gazella) and the springbok (An-tidorcas marsupialis).

Another mating system, lekking, is very rare in mammals. It has been observed most often in the Bovidae, but only in four African forms, all belonging to the subfamily Redunci-nae: Uganda kob (Kobus kob thomasi), white-eared kob (K. k. leucotis), Kafue lechwe (K. leche), and topi. Lekking involves males defending very small territories, often only a few feet (meters) in diameter, located at a specific location called an arena. Many males gather on the same arena, each defending its own small patch of ground, which contains no resources that could attract females. The males defend their territories during day, and females come to them. Once a female enters a territory, the male tries to keep her from moving off long enough so that he can copulate with her. Lekking is not only rare, but is not seen in all populations within a species, nor is it performed each year. It seems to occur more frequently when a population is at high density. At lower densities, each male either holds larger resource territories to attract females, or defends a harem without holding a territory. Lekking is a good example of the flexi-

The Tajik markhor (Capra falconeri heptneri) inhabits the Himalayas. (Photo by R. Van Nostrand/Photo Researchers, Inc. Reproduced by permission.)

bility of social organization in general and of mating systems in particular.

Typically, only males perform courtship; only in rare circumstances do females court males. Although courtship behaviors are species-specific, there are general patterns in common. A male generally approaches females in postures that are non-threatening, and once a female accepts his presence, he will perform additional courtship patterns of increasing physical contact. During this time, the male assesses whether the female is in estrus or not by testing her urine and by her receptive behavior. Such behavior occurs until he is able to mount and copulate with the female. While in many species there may be only three of four distinct courtship patterns, much more elaborate courtship repertoires are found in the Caprinae.

Pregnancy And Childbirth

Pregnancy And Childbirth

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