Dik-Diks

Dik-Diks

Habitat and diet

Social organization

Territorial behavior

Resources

Dik-diks (genus Madoqua ) are small (dog-sized) African antelopes in the subfamily Neotraginae of the family Bovidae, which includes cattle, sheep, and goats,

as well as antelopes, gazelles, and impalas. Other dwarf antelopes including beiras, grysboks, and steenboks, are also classified with the dik-diks in the subfamily Neotraginae. Like all bovids, dik-diks have even-toed hooves, horns, and a four-chambered stomach. There are four species of dik-dik—Kirk’s (M. kirkii ), Günther’s (M. guentheri ), Salt’s (M. saltiana ), silver (M. piacentinii ), as well as a number of subspecies.

Dik-diks weigh only up to 12 lb (6 kg), stand a little over 1 ft (40 cm) in height at the shoulders, and are less than 2 ft (67 cm) in length. They are found in the Horn of Africa, East Africa, and in some parts of southwest Africa. In spite of their small size, dik-diks are heavily hunted for their skin, which is used to make gloves. These small antelopes have big eyes, a pointed snout, and a crest of erect hair on their forehead. They can withstand prolonged high temperatures because of their ability to cool down by nasal panting.

Habitat and diet

Dik-diks live in arid bush country and eat a diet of fallen leaves, green leaves, and fruit. This diet is digested with the aid of microorganisms in the dikdik’s four-chambered stomach and by the regurgitation and rechewing of food (chewing the cud). Because of their small size, the dik-dik’s rumination process is much faster than in larger hoofed animals. With the reduction of forest habitat in Africa over the past 12 million years, it is believed that the small size of animals like the dik-dik has been favorable to their survival.

The dik-dik, like all cud-chewing animals, has a specialized jaw and tooth structure that is adaptable to its diet. The front part of the dik-dik jaw is large compared to the brain area of its skull. The jaws come together elongated, and there are no teeth at the end of the upper jaw. The overall structure functions like a shovel that can tear off great quantities of food at a fast pace and then chop it up for the rumination process.

Social organization

A male and a female dik-dik form a permanent pair bond and together they occupy a territory 12-75 acres (5-30 ha) in size. The female is slightly larger than the male, which reflects her greater role in caring for her offspring. Dik-diks give birth twice a year (coinciding with the rainy seasons) to one offspring at a time. For the first few weeks after its birth, the young dik-dik lies hidden in the bush. Its mother makes contact by bleating sounds which are answered by the offspring.

Like other dwarf antelopes, dik-diks have efficient scent glands that are used to mark their territory. These glands are located in the front part of the eyes (suborbital glands) and on their hooves. Dik-diks are therefore able to mark both the ground and bushes of their territory with their scents.

Territorial behavior

Another distinctive aspect of dik-dik territorial behavior is a ritual that accompanies defecation and urination. The female urinates first, then defecates on a pile of dung that marks their territory. The male waits behind her while she squats during this activity. He then sniffs, scrapes, squats, and deposits his urine and feces over the female’s. Some scent marking of neighboring plants is also part of this ritual. There can be between 6-13 such locations around a dik-dik pair’s territory.

The male dik-dik defends the territory from both male and female intruders. Generally, conflicts over territory are infrequent. While rival males will engage in a rushing ritual, they rarely attack one another physically. The offspring of a dik-dik pair is allowed to remain in the territory until it reaches maturity, which is about six months for females and twelve months for male offspring. The male dik-dik usually intervenes when the mature male offspring tries to approach the mother. The adult male challenge leads to submissive behavior by the younger male. Eventually, the male or female offspring are driven from the territory but they quickly bond with another young dik-dik in an unclaimed territory.

KEY TERMS

Bovids— A family of mammals (Bovidae) that is characterized by having even-toed hooves, horns, a four-chambered stomach, and a cud-chewing habit.

Rumination— Fermentation of plant materials by microorganisms in the four-chambered stomach of bovids, including periods of regurgitation and rechewing (cud chewing).

Resources

BOOKS

Estes, Richard D. Behavior Guide to African Mammals. Berkeley: University of California, 1991.

Nowak, Ronald M. Walker’s Mammals of the World. 6th ed. Baltimore: The Johns Hopkins University Press, 1999.

Vita Richman