Kobus vardoni (Livingstone, 1857)
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publication ID |
https://doi.org/ 10.5281/zenodo.6512484 |
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DOI |
https://doi.org/10.5281/zenodo.6587627 |
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persistent identifier |
https://treatment.plazi.org/id/03F50713-990B-FFB1-0647-FA2EFC4BF517 |
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treatment provided by |
Conny |
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scientific name |
Kobus vardoni |
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Puku
French: Puku / German: Puku / Spanish: Puku
Taxonomy. Antilope vardoni Livingstone, 1857 ,
Chobe Valley, Zambesia.
Two subspecies have been described, but are considered invalid here. Monotypic.
Distribution. Patchily distributed in Angola, E Namibia, NE Botswana, Zambia, SE DR Congo, N & W Malawi, and SW Tanzania. View Figure
Descriptive notes. Head—body 126-156 cm, tail 28-32 cm, shoulder height 77-94 cm; weight 77 kg (males; range 67-91 kg) and 66 kg (females; range 48-78 kg). Males are generally larger than females; territorial males also develop heavy neck musculature (non-territorial males have significantly thinner necks). The pelage of the Puku is long and somewhat rough. Overall coloration is a uniform golden-yellow; the underparts are pale. A dark patch is present on the lowersides of the neck ofterritorial males, caused by the deposition of a greasy secretion from the preorbital glands; these patches are most often seen in May-November. The Puku is easily distinguished from the similar kobs by the absence of black markings on the fronts of the legs, although the distal surfaces may be slightly browner than the body. The pasterns are generally unmarked, although in some individuals a faint white band is visible above the hooves. The tail has a black tip. The face is indistinctly marked with a narrow white ring around each eye and a pale area on the chin. Active preorbital glands are associated with a small tuft of black hair. The ears are generally golden brown externally, but the black tips may covera third of the ear surface in some individuals; the insides of the ears are white. Males are easily distinguished from females by the presence of stout horns. There is relatively little verticalrise from the skull before the horns are deflected backward; when seen in profile, the horns resemble the upward-scooped horns of waterbucks more than the sigmoid-curved horns of kobs. Heavy ridges are present over the basal three-quarters of the horns; typical horn length is 40-54 cm. Dental formulais10/3,C0/1,P 3/3, M 3/3 (x2) = 32.
Habitat. Floodplains and adjacent well-watered grasslands. Seasonally flooded swale habitats are preferred by the Puku, usually containing a mixture of vegetation communities including sedge (Cyperus esculentus ), forbs (Heliotropium spp.), and short grasses (Hemarthria altissima and Cynodon dactylon). Shrubland may be used when floodplains are inundated; in Zambia, mopane (Colophospermum mopane) woodland is used extensively by non-territorial males during the wet season. Dry savannas and areas dominated by annual grass are avoided,as are areas heavily used by domestic cattle. Population densities overall are 1-5—-7-6 ind/km?*. However,in areas of preferred habitat, densities of 6-55 ind/km* (average of 36 ind/km*in central Zambia) are typical, and densities up to 126 ind/km? have been recorded.
Food and Feeding. The Puku is a grazer; perennial grasses are the principal dietary component across seasons (85-9-97-8%, based on observations of foraging individuals). Favored grass species in northern Botswana include Brachiaria latifolia and B. brizantha (December—March and July/August, respectively), Eragrostis lappula and E. rigidior (July/August, December), Setaria sphacelata (December—January), Vossia cuspidata (December) , and Digitaria setivalva (January). Annual grasses are eaten in small amounts in all seasons, but are most consumed during the peak of the dry season (July and August); forbs are also consumed more at this time. Foraging generally occurs on land, but Puku are occasionally observed feeding in water up to 15 cm deep.
Breeding. Breeds year-round. Conflicting reports suggest varying peak breeding seasons; recent evidence suggests that mating peaks during the June-July dry season. During courtship, a male follows an estrous female with his head stretched forward and low. Copulation is preceded by ritualized “laufschlag” in which the male lifts a front leg between a female’s hindlegs and taps her abdomen. Copulation itself lasts for less than five seconds. Length of gestation has not been measured, but is presumed to be approximately eight months. In Zambia, the majority of births occur in the wet season, from January to April; in Botswana, this peak extends from January to June. Neonates weigh approximately 5-8 kg (recorded from a single three-day-old calf) and remain hidden in dense vegetation for a few weeks. After emerging, young Puku show a poorly developed following response, and if startled often flee away from their mothers. Nursing has been observed most frequently in the early morning, but also occurs at other times during the day. Young males disperse from their mothers before one year of age, whereas a young female may remain loosely associated with her dam into adulthood.
Activity patterns. Puku may be observed feeding or moving throughout the day, although activity levels tend to be highest around dawn and dusk. Groups are usually observed foraging in the pre-dawn and early morning, with peak activity subsiding by 08:00 h. Resting often occurs around midday; bedding sites are often in full sun, such as on sand banks or on open grassland, rather than in the shade. Toward the late afternoon, activity levels generally rise again and are sustained into the evening. Anecdotal evidence indicates that foraging may continue after sunset until at least 24:00 h.
Movements, Home range and Social organization. Puku are most commonly seen in small groups, sometimes intermingled with groups of Common Impalas ( Aepyceros melampus). Females associate in loose groups of 6-20 individuals; males are either solitary or found in bachelor herds, which are often structured into subgroups of similaraged males. There do not appear to be strong long-term associations between individuals of either sex. During the dry season, Puku aggregate in areas of good habitat close to water, where groups of up to 46 individuals have been recorded. Females follow vegetation patterns across seasons, shifting their areas of occupancy to coincide with the highest forage quality. In poor-quality habitat, female home ranges average 0-33 km*. In good habitat, the average home range decreases to 0-24 km®. Adult males are territorial and remain in the same home range throughout the year; the reproductive benefit of defending an area preferred by females during the breeding season is thought to offset the energetic costs of not following food resources. In poor-quality habitat, territories are relatively large, averaging 0-14 km?; this may be in response to low female density or poor resource availability. In good-quality habitats, territories tend to be smaller (average 0-05 km?*) and show a clumped distribution. Such grouped territories may represent an intermediate stage toward lekking as seen in the Uganda Kob (K. thomasi) and the White-eared Kob ( K. leucotis ). Females move freely across territorial boundaries with relatively little interference by the resident males. Intruding males, especially bachelors, are driven off in short but intense chases. Territorial ownership is advertized by a series of 2—4 sequential whistling vocalizations and visually by the dark neck patch of territorial males. A single whistle also serves as an alarm call for both sexes; if disturbed, Puku may flee into cover or into water.
Status and Conservation. Classified as Near Threatened on The IUCN Red List. The Puku was once distributed widely throughout south-central Africa, but it is now restricted to isolated pockets of grassland and floodplain habitat. Currently declining populations are the result of illegal hunting, habitat loss, and competition with domestic livestock, especially cattle. The total population is estimated to be 76,000 -130,000 individuals. This species is most common in the unprotected Kilombero Valley region of Tanzania (approximately 75% of total numbers); the remaining majority is found in Zambia. In some regions, notably Chobe National Park in Botswana, Puku numbers are increasing, likely due to the habitat modification caused by recovering populations of other large herbivores such as African Savanna Elephants (Loxodonta africana ).
Bibliography. Corti et al. (2002), Dipotso & Skarpe (2006), East (1999), Goldspink et al. (1998), IUCN/SSC Antelope Specialist Group (2008ag), Kingdon (1982), Rodgers (1984), Rosser (1989, 1990, 1992), Smithers (1966), Von Richter & Osterberg (1977), de Vos & Dowsett (1966).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
