Bovidae Author Don E. Wilson Author Russell A. Mittermeier text 2011 2011-08-31 Lynx Edicions Barcelona Handbook of the Mammals of the World – Volume 2 Hoofed Mammals 444 779 book chapter 58516 10.5281/zenodo.6512484 67b52095-db4b-43f8-a661-4aced0511111 978-84-96553-77-4 6512484 126. Buffon’s Kob Kobus kob French: Cobe de Buffon / German: Senegal-Grasantilope / Spanish: Kob de Buffon Other common names: Senegal Kob , Western Kob Taxonomy. Antilope kob Erxleben, 1777 , Upper Guinea . Buffon’s Kob formerly encompassed all kob species from western, central, and eastern Africa. Based on skull characteristics, the four former subspecies have been elevated to species, and K. kob is now taken to be restricted to Africa west of Nigeria . This species is considered monotypic here. Distribution. Senegal to W Nigeria . Descriptive notes. Head-body ¢.160-180 cm, tail 10-15 cm, shoulder height 90-100 cm (males) and 82-92 cm (females); weight 60 kg (males) and 45 kg (females). Buffon’s Kob is a relatively small kob . The pelage is short and smooth. The overall color is golden brown or orange, and the underparts and inner surfaces of the legs are white. The outer surfaces of the legs are the same color as the body. An indistinct black stripe is present on the front of all four limbs, and a white band is present above the hooves. On the face, white markings are present around the eyes, at the base of each ear, and on the muzzle and lips. The ears have pale interiors and golden backs with blackish tips. The lyre-shape horns are present only in males; as with body size, the horns of Buffon’s Kob tend to be smaller than those of other kobs. Average length in mature males is 48-55 cm;their spread at the tips may be 14-37 cm depending on the degree of divergence at the base and the inward curvature at the tips. Dental formula i510/3,C0/1,P3/3,M 3/3 (x2) =32 Habitat. Savannas and alluvial plains. Buffon’s Kob inhabits grasslands closely associated with lakes and rivers; it is rarely found more than a few kilometers away from a permanent water source, particularly during the dry season. Open savannas are the principal habitat during the wet season (approximately 70% of sightings occur in this zone). In the dry season, grass savannas with trees (especially Combretum, Terminalia macroptera, and Detarium) and bushes are preferred (at a similar rate of 70% of sightings). Dense gallery forests are avoided. Historically, population densities of Buffon’s Kob were highest in savannas, averaging 9-20 ind/km?; the onset of the rainy season (April) produced extremely high local densities of up to 97 ind/km?. However,as a result of habitat destruction and hunting, current population densities across the range of Buffon’s Kob are generally less than 1 ind/km?, in some cases below 0-1 ind/km?. Food and Feeding. A selective grazer. Buffon’s Kob feeds on grass throughoutthe year, but tends to be less selective during the wet season. Dry season burns coupled with the rains create a flush of new growth at the start of the wet season; grasses like Andropogon africanus, A. gayanus, A. tectorum, Echinochloa colonum, and Brachiaria mutica are favored at this time of year. In the wooded savannas used during the dry season, Hyparrhenia subplumosa, Schizachyrium sanguineum, and Vetiveria fulvibarbis are preferentially consumed; Buffon’s Kob will also occasionally browse on the young leaves of woody plants (e.g. Digitaria ciliaris). This species drinks daily, and may consume mineral-rich soils, particularly during the dry season when the mineral content of grasses is lowest. Breeding. Buffon’s Kob may breed throughout the year, although a peak in matings is seen in February and March. Births are usually concentrated at the start of the dry season (December—January in Ivory Coast ). The breeding system appears to be density-dependent. Lekking, as seen in the Uganda Kob (K. thomasi) and the White-eared Kob ( K. leucotis ), formerly occurred in areas where population density exceeded approximately 15 ind/km?; these densities are rare in modern West Africa, and lekking is now uncommon. Breeding males tend to be territorial; females pass freely through territories without any attempt on behalf of the male to prevent their egress. A male will follow an estrous female with his neck stretched forward and head low. Ritualized foreleg kicks (“laufschlag”) are a prelude to mounting. Other reproductive parameters are unknown but are likely similar to those of the Uganda Kob . Interbirth intervals tend to be longer than twelve months. Juvenile males are generally forced from their natal herds at eight months of age. Life expectancy in the wild is estimated to be 6-7 years. Activity patterns. Buffon’s Kob tends to be active throughout the day and night. Diurnal observations of captive animals indicate a peak in foraging from 09:00 h to 11:00 h and from 17:00 h to nightfall. Unusually, these animals were observed to rest and ruminate in the early morning, a time when activity levels among ungulates are often high; whether the animals were using the early hours to warm up after night-time foraging or were expressing an artifact of their captivity is unknown. A more typical period of rest and rumination occurs at midday, from 12:00 h to 15:00 h. Of the daylight activity budget, 43-3% is spent feeding; a similar proportion (38:3%) is spent ruminating. Activity levels, as measured by distances traveled, are higher during the day (average displacement of 2-4 km) than at night (1-9 km). Distances covered tend to be greater during the dry season (December—March) in response to less abundant food resources. Movements, Home range and Social organization. Buffon’s Kob displays a variety of social patterns, from solitary individuals to large herds of 100 animals or more. A documented decline in population numbers has been accompanied by a shift in social organization toward smaller herds and largerterritories. The largest groups are observed during the dry season (December-March), when Buffon’s Kobs travel en masse to drinking sites. These large herds are usually temporary, fragmenting after returning to wooded savanna where most dry season foraging occurs. Large herds also form at the beginning of rainy season (April-July) when the species emerges onto open grasslands. In 1974, the typical group size across the year was estimated to be 20 animals; however, herds of 1-5 animals now account for over 70% of observed groupings. Buffon’s Kob herds are very flexible: individuals often join or leave, so the composition of any given group is usually different after a five-hour period. Females constitute the majority of individuals in large herds. Males are more solitary, although young males associate in bachelor herds (these male-only herds are largest during the wet season). Solitary Buffon’s Kobs account for a significant proportion of observations. Isolated males are often territorial and exclude other males from their home ranges even when no females are present. Average territory size is between 0-63 km*and 0-92 km* (range 0-36-1-27 km?); this is significantly smaller than the average home range of females (2: 46 km ?). In the 1970s, reported territory size was much smaller (0-03-0-13 km?): the disparity is thought to be due to continued declines in population densities. In Ivory Coast , males show territorial tendencies beginning at three years of age, and most (c.90%) adult males maintain a territory. Territorial boundaries are maintained using displays, including a “proud gait” in which the head is held high and erect. Fights are generally rare. As in the related reedbucks ( Redunca spp.), distinctive whistles may indicate to other males that a territory is occupied. Males occupy their territories throughout the year and, although they may leave to drink during droughts, the boundaries themselves are not affected by season. Females frequently shift their home rangesin the late wet season (August-November) to take advantage of changing food resources. Status and Conservation. Classified as Vulnerable on The IUCN Red List (under K. kob kob ; this classification also includes western populations of K. loderi). Buffon’s Kob is severely threatened by habitat loss due to agriculture and excessive hunting by humans; it has been extirpated from large parts of its former range. The majority of surviving Buffon’s Kobs are restricted to protected areas, and even these populations have declined (some by over 90%) in recent decades. The total population is likely 40,000 — 75,000 , with a large proportion (¢.26,000) inhabiting Niokolo-Koba National Park in Senegal . Other significant populations are found in Arli National Park ( Burkina Faso ), Comoé National Park ( Ivory Coast ), and Mole and Bui National Parks ( Ghana ). Bibliography. Agbelusi (1989, 1991), East (1999), Fischer & Linsenmair (1999, 2001b, 2002, 2007), Geerling & Bokdam (1971), IUCN/SSC Antelope Specialist Group (2008y), Kingdon (1997), Lydekker (1914), Muhlenberg & Roth (1985), Sodeinde (1989).