Kobus loderi (Lydekker, 1900)
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publication ID |
https://doi.org/ 10.5281/zenodo.6512484 |
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DOI |
https://doi.org/10.5281/zenodo.6636842 |
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persistent identifier |
https://treatment.plazi.org/id/03F50713-9977-FFCC-034F-FC53F7FEFA55 |
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Conny |
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scientific name |
Kobus loderi |
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Loder’s Kob
French: Cobe de Loder / German: Kamerun-Grasantilope / Spanish: Kob de Loder
Other common names: Cameroons Kob
Taxonomy. Cobus vardoni loder: Lydekker, 1900 ,
“type locality unknown.”
Loder’s Kob is a relatively unrecognized member of the kob species complex, formerly described as the subspecies K. kob loderi. Most recent treatments have recognized only three kob groupings ( K. kob , K. thomasi , and K. leucotis ), ignoring K. lodert . Populations west of Sudan are often ascribed to K. kob sensu stricto, and populations in DR Congo and Sudan are usually listed under K. thomasi . The species is considered to be unique on the basis of skull morphology. Monotypic.
Distribution. E Nigeria to W Sudan and N DR Congo. The divisions between the ranges of K. loderi , K. leucotis , and K. thomasi in Sudan are poorly understood. View Figure
Descriptive notes. No confirmed measurements are available. This species is generally similar to Buffon’s Kob ( K. kob ). Males are the larger sex and have prominent muscle definition, especially on the neck; females are more slender and lightly built. The overall color of both sexes is tawny to reddish-brown; males tend to be more richly colored (brighter and darker) than females. Specimens from the eastern parts of the species’ distribution may have a speckling of black hairs throughout the coat. Underparts are white. A black line marks the fronts of the lower legs; the forelegs are more heavily marked than the hindlegs. The pasterns are white, except where bisected by the aforementioned black lines. The neck and face are paler than the rest of the body. Facial markings are generally inconspicuous, comprised of a thin area of white above each eye and white lips, but are generally inconspicuous; the markings may be more prominent in eastern specimens. The inner surfaces of the ears are white; the outer surfaces range from fawn to whitish. Females are hornless. The horns of males are stout and possess a sigmoid flexure, rising vertically from the skull, then curving backward, and finally upward at the tips. Prominent transverse ridges are present along most of the horn length. The horns tend to be shorter than in Buffon’s Kob ; the type specimen has horns 53 cm long. Horns from Sudanese specimens tend to have a greater span than those from Central Africa. Dental formulais10/3,C0/1,P 3/3, M 3/3 (x2) = 32.
Habitat. Floodplains and savanna grasslands. In Cameroon, preferred savanna habitats are interspersed with Terminalia laxiflora woodland. Loder’s Kob is rarely found more than 10 km from a permanent source of water. Population densities are generally low, typically 1-2 ind/km? but sometimes as high as 12 ind/km?.
Food and Feeding. As with other kobs, Loder’s Kob feeds primarily on grasses. The grass species Echinochloa pyramidalis, E. stagnina, Vossia cuspidata, Paspalum orbiculare, Hyparrhenia spp., and Jardinea congoensis are commonly consumed during the dry season. Data from Cameroon indicate that other ground-level plants (forbs) may comprise up to 25% ofthe diet. Shrubs may also be consumed during the dry season when grass quality is low. Loder’s Kob drinks regularly.
Breeding. Loder’s Kob breeds throughout the year in Cameroon. A peak in breeding behavior occurs during the dry season (February-March). Lek breeding has not been recorded. Courtship often involves a parallel walk by a pair. Gestation is approximately nine months;littersize is one. Prior to giving birth, a female isolates herself and seeks out dense brush. This cover provides protection for the neonate, which remains concealed in the birthing location for at least the first week of life; the dam forages nearby and visits the infant intermittently to nurse. After 8-14 days, the infant leaves the thicket and accompanies its mother as she forages, often resting nearby. Grasses are tested beginning at 3—4 weeks, and weaning occurs at approximately three months. Both sexes reach sexual maturity at 12-16 months of age, but males are not socially mature (i.e. able to maintain a territory and thus breed) until after their third year. Longevity in captivity may exceed eleven years.
Activity patterns. There is no specific information available for this species, but likely similar to the closely related Buffon’s Kob .
Movements, Home range and Social organization. The reliance of Loder’s Kob on permanent water year-round precludes widespread dispersal during the wet season, although they are more evenly distributed across available habitat types at this time. During the dry season, Loder’s Kob tends to concentrate around water sources. Large herds composed of both sexes may be seen at this time; in Waza National Park, Cameroon, such herds may number in the hundreds. However, these large groupings no longer occur in much of the species’ distribution, and herds with more than 25 individuals are rarely seen. The mean groupsize across the year in Bénoué National Park, Cameroon,is 3-7 animals; single sex herds are most frequently observed. Females are generally gregarious; mature males are often solitary. This pattern is especially prominent during the breeding season when males become territorial and exclude other males from their vicinity. Territories are delineated with urine, feces, and scent marks along the boundaries. They are also visually declared: males will stand on raised areas such as anthills to advertise their presence to neighboring males. Closely matched males may fight vigorously overterritorial ownership. After an initial “sizing up” phase, the rival males will rush toward each other, crashing their horns together and then grappling, with horns interlocked, trying to throw each other off-balance. Non-territorial males (typically immature males and very old individuals) form bachelor herds. Because mature males are often territorial, they do not form permanent attachments to female groups. “Harem groups” (with one male and numerous females) may form briefly as female herds pass through a male’s territory.Juveniles around six months old often associate in “nursery groups” accompanied by a few adult females; bouts of chasing, jumping, sparring, and other forms of play are frequent in these herds.
Status and Conservation. Classified as Vulnerable on The IUCN Red List (under K. k. kob ). The distribution of Loder’s Kob has contracted significantly in recent decades, with most large populations now existing in protected areas. Population numbers have also declined; rinderpest was responsible for a massive die-off in Waza National Park, Cameroon in 1982-1983, but ongoing illegal hunting is thought to be the main limiting factor. No complete population estimates exist, but based on available information, at least 30,000 Loder’s Kobs survive.
Bibliography. Agbelusi (1989), East (1999), Esser (1980), IUCN/SSC Antelope Specialist Group (2008y), IUCN/ SSC Antelope Specialist Group (2008aa), Kingdon (1997), Lydekker (1914), Mayaka et al. (2004), Muhlenberg & Roth (1985), Stark (1986b), Wanzie (1988, 1991), Weigl (2005).
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