Dik-dik

Dik-Dik [1]
Male, Tarangire National Park, Tanzania
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Artiodactyla
Family:	Bovidae
Genus:	Madoqua (Ogilby, 1837)
Species
Madoqua guentheri Madoqua kirkii Madoqua piacentinii Madoqua saltiana

For the pop group, see Dik Dik.

A dik-dik, pronounced "dĭk’ dĭk", is a small antelope in the Genus Madoqua that lives in the bushes of eastern and southern Africa. Dik-diks stand 30–40 cm (approx. 12–16 inches) at the shoulder, are 50–70 cm (approx. 20-28 inches) long, weigh 3–6 kg (approx. 7-16 pounds) and can live for up to 10 years. Dik-diks are named for the alarm calls of the females. In addition to the female's alarm call, both the male and female make a shrill whistling sound. These calls may alert other animals to predators.

Physical characteristics

Female dik-diks are somewhat larger than males. The males have horns, which are small (about 3 in or 7.5 cm), slanted backwards and longitudinally grooved. The hair on the crown forms an upright tuft that sometimes partially conceals the short, ribbed horns of the male. The upper body is gray-brown,while the lower parts of the body, including the legs, belly, crest, and flanks, are tan. A bare black spot below the inside corner of each eye contains a preorbital gland that produces a dark,sticky secretion. Dik-diks insert grass stems and twigs into the gland to scent-mark their territories.

To prevent overheating, dik-diks have elongated snouts that have bellow-like muscles with which blood is pumped. Airflow and subsequent evaporation cools this blood before it is recirculated to the body. However, this panting is only implemented in extreme conditions—dik-diks can tolerate temperatures of up to 104° Fahrenheit (40 °C).^[2]

Habitat

The Dik-dik lives in shrublands and savannas of eastern Africa. Dik-diks seek habitats with plentiful supply of edible plants such as shrubs. Dik-diks may live in places as varied as dense forest or open plain, but they require good cover and not too much tall grass.^[3] They usually live in pairs over a 5 hectare (12 acre) territory. The territories are often in low, shrubby bushes along dry, rocky streambeds where there are plenty of hiding places. Dik-diks can blend in with their surroundings, because of their dusty colored fur. Dik-diks have a series of runways through and around the borders of their territories.^[4]

Dik-diks have adapted to arid conditions, and can live through hot temperatures.

Diet

Dik-diks are herbivores. Their diet mainly consists of foliage, shoots, fruit and berries. Dik-diks receive sufficient amounts of water from their food, making drinking unnecessary. Like all even-toed ungulates, they digest their food with the aid of microorganisms in the their four-chambered stomach. After initial digestion, the food is repeatedly regurgitated and re-chewed, a process known also as chewing the cud. Dik-diks' specially shaped tapering head may help them eat the leaves between the spines on the Acacia trees, and the ability to feed while still keeping their head high to detect predators.^[2]

Social structure

Dik-diks are monogamous^[5] . Conflicts between territorial neighbors seldom occur. When this is the case the males from each territory dash at each other, stop short, vigorously nod their heads and turn around. They will repeat this process increasing the distance each time until one stops. Males mark their territory with dung piles, and cover the female's dung with their own.^[6] Monogamy may be an evolutionary response to predation;^[7] surrounded by predators, it is dangerous to explore, looking for new partners.^[8] Pairs spend approximately 64% of their time together. Males, but not females, will attempt to obtain extra-pair mating when the opportunity arises.^[9]

Females are sexually mature at 6 months and males at 12 months. The female gestates for 169 to 174 days and bears a single offspring. This happens up to twice a year(at the start and finish of the rainy season). Unlike other ruminants, the dik-dik is born with its forelegs laid back along-side its body, instead of them being stretched forward. Females weigh approximately 560 to 680 grams at birth, while males weigh 725 to 795 grams. The mother lactates for 6 weeks, feeding her fawn for no longer than a couple of minutes at a time. The survival rate for young dik-diks is 50 percent. The young stay concealed for a time after birth, but grow quickly and reach full size by the age of 7 months. At that age the young are forced to leave their parent's territory. The fathers run the sons off the territory and the mothers run off the daughters. ^[10]

Predators

Dik-diks are hunted primarily by monitor lizards, and smaller cats such as the caracal, as well as lions, hyenas, wild dogs, and humans. The dik-dik's other predators are leopards, cheetahs, jackals, baboons, eagles, hawks and pythons. Dik-diks' adaptation to predation include excellent eyesight and the ability to reach speeds up to 42 kilometers (26 mi) an hour.^[11]

Classification

There are four species of dik-dik:^[1]

• Madoqua gunther (Günther, 1894) – Günther's Dik-dik
• Madoqua kirkii (Günther, 1880) – Kirk's Dik-dik
• Madoqua piacentinii (Drake-Brockman, 1911) – Silver Dik-dik
• Madoqua saltiana (Desmarest, 1816) – Salt's Dik-dik

Gallery

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  Dik-dik eating

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  Family of Kirk's Dik-dik, Lake Manyara, Tanzania

References

1. ^ ^{a b} Grubb, Peter (16 November 2005). "GENUS Madoqua". In Wilson, Don E., and Reeder, DeeAnn M., eds. Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Baltimore: Johns Hopkins University Press, 2 vols. (2142 pp.). ISBN 978-0-8018-8221-0. OCLC 62265494. http://www.bucknell.edu/msw3/browse.asp?id=14200592. 
2. ^ ^{a b} "African Wildlife Foundation: Dik dik." Web. 4 Feb 2010. <http://www.awf.org/content/wildlife/detail/dikdik>.
3. ^ "Savanna." Blue Planet Biomes. 11/7/06. Brynn Schaffner and Kenneth Robinson, Web. 9 Feb 2010.<http://www.blueplanetbiomes.org/savanna.htm>.
4. ^ "The Living Afridca: Wildlife Bovid Family." Web. 4 Feb 2010. <http://library.thinkquest.org/16645/wildlife/dik-dik.shtml>.
5. ^ Brotherton, PNM; JM Pemberton, PE Komers, G Malarky (1997). "Genetic and behavioural evidence of monogamy in a mammal, Kirk's dik-dik (Madoqua kirkii)". PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON SERIES B-BIOLOGICAL SCIENCES 264: 675–681. 
6. ^ http://science.jrank.org/pages/2091/Dik-Diks-Territorial-behavior.html
7. ^ http://cat.inist.fr/?aModele=afficheN&cpsidt=2083197
8. ^ National Geographic; June, 1996, "Earth Almanac"
9. ^ . PMC 1688408. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1688408. 
10. ^ Scheibe, E. 1999. "Madoqua kirkii." Animal Diversity Web. 27 Jan 2010. University of Michigan Museum of Zoology, Web. 29 Jan 2010.
11. ^ "The Living Afridca: Wildlife Bovid Family." Web. 4 Feb 2010. <http://library.thinkquest.org/16645/wildlife/dik-dik.shtml>.