The dik-dik evolved in the Miocene, 12 million years ago. That their small size is a secondary adaptation is suggested by the observation that their gestation time is more typical of the larger hoofed mammals. (Kingdon 1982) The dik-dik's main predators are leopards, cheetahs, jackals, baboons, eagles, and pythons. They are able to escape them with their excellent eyesight and ability to reach speeds up to 42 kilometers an hour. (MacDonald 1985)
Perception Channels: tactile ; chemical
The reduction of habitat due to slash-and-burn cultivation has meant that the dik-dik's small size is increasingly favored because of the secondary growth that appears in the damaged area. The growth provides an ideal food source and hiding place for the dik-dik. (Kingdon 1982)
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
Hunters dislike this animal because they flush and warn the larger game of the danger (Nowak 1991).
Dik-diks are extensively hunted in some areas for their skins, which are used in the production of gloves. It requires one hide to make one glove. (Parker 1990)
Positive Impacts: food ; body parts are source of valuable material
Because dik-diks are so small, their metabolic requirement per kilogram is high and they must consume more food per kilogram of body weight than larger hoofed mammals. They share a habitat with kudu, which keep the shrubs within one meter of the ground, and with zebra, which keep down the grass (Kingdon 1982). This allows a food source to grow abundantly at an ideal level for the dik-dik. They require vegetation that is easily digested and low in fiber. Eighty percent of their diet comes from the leaves of trees and shrubs; 17 percent comes from grasses; and the remainder comes from herbs and sedges (Parker 1990). They mostly feed from dawn to mid-morning and from mid-afternoon until dark (Parker 1990). The only moisture they consume for months at a time is the dew on vegetation and the little moisture in the vegetation (Nowak 1991).
Dik-diks are found in extreme southeastern Somalia, central and southern Kenya, northern and central Tanzania, southwestern Angola, and Namibia (Nowak 1983).
Biogeographic Regions: ethiopian (Native )
Dik-diks inhabit arid bush country, not extending too far into the savanna. They need heavy shrubbery to hide in and feed on, but they do not require much water.
Terrestrial Biomes: scrub forest
Average lifespan
Status: captivity: 17.3 years.
The dimensions of an adult dik-dik are as follows: body length is 520-670 mm, tail length is 35-55 mm, and height measured at the shoulder is 305-405 mm (MacDonald 1985). Its coloration is yellowish gray to reddish brown on its back and grayish to white on its belly. Horns are only found on males; they are ringed and stout at the base. They can be concealed at times by a tuft of hair on the animal's forehead. Accessory hooves are small and its tail is conspicuous. The most distinguishing feature of this particular species of dik-dik is that its snout is particularly elongated into a proboscis. This proboscis is an adaptation for cooling that allows venous blood to cool by evaporation from the mucous membrane into the nasal cavity during normal breathing or under great heat stress from nasal panting (Kingdon 1982).
Range mass: 3 to 6 kg.
Other Physical Features: endothermic ; bilateral symmetry
Average basal metabolic rate: 11.966 W.
Female dik-diks are sexually mature at 6 months of age and males are ready to reproduce at 12 months. Males and females form permanently mated pairs that occupy an area anywhere from 5 to 30 hectares (12.5-75 acres) (Nowak 1983). The male courts the female by running up behind her with his head and neck stretched and his muzzle pointing out in front. Copulation begins with the male standing on his hind legs behind the female and waving his forelegs at an acute angle to his own body in the air over her back (Kingdon 1982).
Mating System: monogamous
For the next 169 to 174 days the female gestates and bears a single offspring. This happens twice a year. Births peak from November through December and from April through May (the start and finish of the rainy season). Different from most other ruminants, the dik-dik is born with its forelegs laid back along-side its body, instead of them being stretched forward (Kingdon 1982). A female weighs approximately 560 to 680 grams at birth, while males weigh 725 to 795 grams (MacDonald 1985).
Breeding interval: Breeding occurs twice yearly.
Range number of offspring: 1 (low) .
Average number of offspring: 1.
Range gestation period: 5.63 to 5.8 months.
Average gestation period: 5.7 months.
Range weaning age: 3 to 4 months.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Average birth mass: 600 g.
Average number of offspring: 1.
Average age at sexual or reproductive maturity (male)
Sex: male: 304 days.
Average age at sexual or reproductive maturity (female)
Sex: female: 213 days.
The mother lactates for 6 weeks, feeding her young for no more than a couple of minutes at a time. The young stay concealed for a time after birth, but grow quickly to reach full size at 7 months of age (Nowak 1983). The rate of survival for fawns is 50 percent (MacDonald 1985). The young are forced to leave the territory at about seven months of age; mothers run off their daughters and fathers run their sons out of the territory. The first few times the father attempts to keep his son from approaching his mother, the father dashes for him and the son drops to the ground and exposes his neck as a sign of submission. He is then allowed to stay a little longer in the area, but will soon be forced to leave (Kingdon 1982).
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Male, Female)
Kirk's dik-dik (Madoqua kirkii) is a small antelope native to Eastern Africa and one of four species of dik-dik antelope.[2] It is believed to have six subspecies and possibly a seventh existing in southwest Africa.[3] Dik-diks are herbivores, typically of a fawn color that aids in camouflaging themselves in savannah habitats.[3] According to MacDonald (1985), they are also capable of reaching speeds up to 42 km/hour.[4] The lifespan of Kirk's dik-dik in the wild is typically 5 years, but may surpass 10 years.[4] In captivity, males have been known to live up to 16.5 years, while females have lived up to 18.4 years.[4]
The dik-dik's name is derived from its call.[2] When they feel threatened, dik-diks lie low to prevent detection.[2] If they are discovered, they run in a swift, zigzag-like pattern until they reach refuge in a nearby thicket.[2] During this ‘flight’, they emit trumpet-like "zik-zik" calls to raise an alarm or to harass predators and publicize the presence of a mated pair.[2]
Dik-diks are some of the world's smallest antelopes, with the largest, the Kirk's dik-dik, standing between 14 and 18 inches tall and weighing no more than 7.2 kg (16 lb).[2] Female dik-diks tend to be 1 to 2 pounds heavier than males.[2] They are dainty creatures with a pointed, mobile snout, large eyes and ears, prominent preorbital glands, pipestem legs, hare-like hind limbs that are significantly larger than their forelimbs, and a vestigial tail.[2] Their coats, depending upon their habitat,[5] range from grey to gray-brown with tan flanks, limbs, and an erectile head crest and whitish eye rings, ear lining, underparts, and rump.[2]
Only male dik-diks sport horns, which are about 3 in (8 cm) long, corrugated, and backward-slanted.[2] Horns of male Kirk's dik-diks may be straight or curved backwards from the profile of the face, and the basal half of the horns have seven to nine annular ridges that are frequently covered by the crest.[4] Kirk's dik-diks are sexually dimorphic; females are larger and lack horns, while males sport a more developed muzzle, have a longer crest, and tend to be lighter in color.[6] Though physically very similar, Kirk's dik-dik can be distinguished from Guenthers’ dik-dik by its longer nasals and premaxillae and shorter proboscis, which gives the head a more wedged-shaped profile than that of Guenther's dik-dik.[4]
Kirk's dik-diks are highly adapted to surviving in the arid regions of eastern Africa. They have a hairy proboscis with tiny, slit-like nostrils, a feature that is most pronounced in Guenther's dik-diks.[7] This proboscis contains an enlarged nasal chamber supplied with a rich amount of blood that is cooled by rapid nasal panting.[7] Panting through their snouts leads to airflow and evaporation that cools the blood before it is pumped back into the body. This process is also efficient, because it results in a minimal loss of water in the exhaled air.[2] Water- and energy-conserving methods, such as fluctuating body temperatures, lowered metabolic rates, concentrated urine, and dry feces, all contribute to the ability of the dik-dik to survive harsh arid climates.[2] Further,[8] they also conserve fluids by licking dew from their nose and reabsorbing water from their feces.[4] When compared to cattle, dik-diks have a significantly lower density of sweat glands.[4]
Behaviorally, dik-diks are highly nocturnal, and during the daytime seek shade to rest throughout the hottest parts of the day to help avoid the loss of valuable fluids.[7] Dik-diks are also highly selective when browsing on succulents, herbs, and foliage as to maximize fluid acquisition.[2] The hind legs of Kirk's dik-diks are longer and are structurally more uniform, than the fore legs.[4] Hopwood 1936 suggests this helps the hind legs propel the dik-dik forward, as the relatively short fore legs of dik-diks are more efficient at ascending broken terrain.[4]
"Kirk's dik-dik are endemic to savannah areas of eastern and southwestern Africa, occurring primarily in the Somali and Southwest arid biotic zones, but encroaching into the Southern savannah biotic zone".[4] Their distribution can be described as discontinuous and as a result they often occur in dispersed patches due to their unique habitat requirements.[4] In Namibia, Kirk's dik-dik occur in isolated areas along the Fish River and do not reside in the Namib desert, though they may traverse desert thickets along sources of water.[4] They prefer habitats with good cover but lacking tall vegetation.[5] Ideal habitats contain a variety of browse, extensive shade, and an open understory at their eye level.[4] (Tinley, 1969) As a result, they move to different ranges when grass grows too high and obstructs their view.[5] As noted by Tinley (1969), typical habitats of Kirk's dik-dik consist of thicket mosaics characterized by well-developed shrub layers and scant short grass cover.[4] Dik-diks live in pairs on territories of 2–86 acres, depending on cover and resources.[2] If no unfavorable events occur a pair of Kirk's dik-dik may reside within the same territory for life.[9] Males are the main defenders of territories, as females are unable to maintain territories themselves.[4] (Kingdon 1982) According to MacDonald (1985), territorial conflicts over quality habitat are not frequent, however, when do they occur, males charge one another, stopping just short of physical contact, before repeating the process by running from a longer distance.[4] Furthermore, the encounter ends when one male surrenders, which results in both males scratching at the ground, urinating, and defecating".[4]
Dik-dik are herbivorous and their diets consist mainly of foliage, fruits, shoots, and berries.[7] Due to their adaptations, dik-diks are water-independent and rely on vegetation as a source of water.[7] Kirk's dik-diks are concentrate selectors, feeding selectively on dicotyledonous plants that can be rapidly fermented and digested. This includes leaves and fruit high in nutrients and water, but low in fiber and cellulose. Grasses are only consumed when they are germinating and Kirk's dik-diks have stomach capacities and mass that consist of 8.5–10.0% of body mass when full and 2.2% when empty".[4] Because of the aforementioned facts and their high food requirements, Kirk's dik-diks feed and ruminate periodically throughout day and night.[4] They consume roughly 3.8% of their body mass daily.[4]
Similar to other dwarf antelopes, Kirk's dik-diks exist in monogamous pairs on territories.[2] Territories are marked with dung and urine that are deposited in a ritual that is performed to help maintain pair bonds.[2] During the ritual, the female will excrete, followed by the male, which samples the female's urine stream to check her reproductive capacity.[2] He paws over and then marks his dung and urine over her deposit.[2] Finally, the pair marks nearby twigs with secretions from their preorbital glands.[2] The male courts the female by running up behind her with his head and neck stretched and his muzzle pointing out in front. Copulation begins with the male standing on his hind legs behind the female and waving his forelegs at an acute angle to his own body in the air over her back".[4] Copulation typically occurs three to five times within a 9-hour period.[4]
Kirk's dik-diks have a gestation period of 5–6 months, and may produce up to two offspring per year.[2] Females reach sexual maturity between 6 and 8 months of age, while this occurs for males between 8 and 9 months.[9] Dik-diks produce one offspring per gestation.[2] Most births occur between November and December and April through May, which coincides with the timing of the rainy seasons.[4] Dik-diks differ from other ruminants in that offspring are born with their fore legs along the body, rather than extended forward.[4] After birth, the offspring lie concealed away from their mother 2–3 weeks, and survival rates for fawns are roughly 50%.[4][9] Once offspring reach a certain age, they also begin to participate in the bonding ritual, and remain with the parents until another offspring is born.[2] At this point, the parents chase the older sibling out of their territory.[7] The older offspring then seeks out its own territory and mate.[2]
Dik-diks in general have complex chromosomal arrangements.[10] They typically have 2n=46 to 2n=48 arrangements; however, dik-diks with 2n=49 have been discovered, as well.[10] Furthermore, some have 47 chromosomes with X/A translocation.[10] The two common cytotypes (46- and 48-chromosome individuals) are different enough so that resulting hybrids are sterile.[10] Many zoos are now known to harbor hybrids between different cytotypes, with anomalous chromosome numbers and causing unexplained sterility.[10] Examination of these individuals shows a lack of spermatogenesis in males, for example hybrids between Kirk's and Guenther's dik-diks are infertile.[10]
Dik-diks are susceptible to a myriad of predators including eagles, wildcats, jackals, caracals, leopards, hyenas, cheetahs, Cape wild dogs, honey badgers, crocodiles, pythons, lions, monitors, and humans.[2][7][9] Young dik-diks are particularly preyed upon by baboons, genets, and eagles. Dik-diks have fine-tuned senses of hearing, sight, and smell. When they feel in danger or hear the alarm calls of other animals, they hide, rather than flee. Only when frightened or disturbed do they emit their iconic "zik-zik" alarm.
Humans are the greatest threat to dik-diks, which are sometimes hunted for their hides and bones, often using snares.[5] The bones from their legs and feet are used in traditional jewelry, while their hides are fashioned into suede gloves.[5] An entire dik-dik hide is required to produce a single glove.[4] Nowak (1991) asserted that dik-dik are disliked by local hunters because they flush and warn larger game to the presence of humans.[4] Dik-diks also benefit from the destruction of vegetation via human-mediated slash-and-burn agriculture that results in the subsequent secondary growth of shrubs that serve as a food source and place of refuge for dik-diks.[4] The IUCN Redlist lists Kirk's dik-dik as "least concern".[1]
Usually, four subspecies of Kirk's dik-dik are distinguished, but they may represent three or more distinct species:[11]
M. k. damarensis
female, Etosha National Park, Namibia
Juvenile
Family, Lake Manyara, Tanzania
{{cite web}}: CS1 maint: archived copy as title (link) Kirk's dik-dik (Madoqua kirkii) is a small antelope native to Eastern Africa and one of four species of dik-dik antelope. It is believed to have six subspecies and possibly a seventh existing in southwest Africa. Dik-diks are herbivores, typically of a fawn color that aids in camouflaging themselves in savannah habitats. According to MacDonald (1985), they are also capable of reaching speeds up to 42 km/hour. The lifespan of Kirk's dik-dik in the wild is typically 5 years, but may surpass 10 years. In captivity, males have been known to live up to 16.5 years, while females have lived up to 18.4 years.
