Alcelaphus cokii, Gunther, 1884

Don E. Wilson & Russell A. Mittermeier, 2011, Bovidae, Handbook of the Mammals of the World – Volume 2 Hoofed Mammals, Barcelona: Lynx Edicions, pp. 444-779 : 652-653

148.

Kongoni

Alcelaphus cokii

French: Bubale kongoni / German: Kongoni-Kuhantilope / Spanish: Alcelafo de Coke

Other common names: Coke's Hartebeest

Taxonomy. Alcelaphus cok: Gunther, 1884 ,

Mlali Plains, east of Mpapwa, Tanzania.

Formerly considered a subspecies of A. buselaphus , which is now extinct. In the late 20™ century, it was customary for all or most hartebeest to be included as subspecies of A. buselaphus . There seems no particular reason for them to have been placed in a single species, and the more we learn about them the more distinct they are found to be. A phylogeny of hartebeest based on the control region of mtDNA found some intermixing between the four species of the East African group ( A. lelwel , A. cokii , A. swaynei , and A. tora ): two haplotypes of Swayne’s Hartebeest ( A. swaynei ) were nested within the Kongoni, and three of A. cokii (out of quite a large number) nested within the Lelwel Hartebeest ( A. lelwel ). A hybrid swarm at one time lived (and may, in small pockets,still live) in the Rift Valley in Kenya between A. cokii and A. lelwel , in absolute skull length, as well as in relative horn span, they overlap with each of the two parent species, and are more variable than either. The hybrids are predominantly of A. lelwel type to the north, from Lake Baringo to Mount Kenya, whereas to the south, from Lake Victoria to the southern Rift Valley in Tanzania, they tend to be more like A. cokii . Monotypic.

Distribution. S Kenya and N Tanzania; the distribution extends approximately from Lake Nakuru and S of Mt Kenya, through the S part of Tsavo East National Park, to about the N edge of the Brachystegia zone in N Tanzania, more or less along a line between the coast opposite Zanzibar and the S end of Lake Victoria. There is some evidence that pockets ofthis species occur farther S in suitable areas in the Brachystegia zone that are otherwise the habitat of Lichtenstein’s Hartebeest ( A. lichtensteinii ).

Descriptive notes. Head-body 177-200 cm, shoulder height 117-120 cm (males) and 112 cm (females); weight 129-171 kg (males), 116-148 kg (females). A small species, greatest skull length 41.9-46 cm in males; horn span 97-128% of basal length in males; and least frontal width 57-72% of biorbital width. The horns, seen from in front, are more widespread than in the Tora Hartebeest (A. tora ) and Swayne’s Hartebeest, so that their shape resembles a curly bracket on its side. They are relatively short and are more slender than in other hartebeest species except for the Tora Hartebeest and Swayne’s Hartebeest. In this feature, and in skull weight, the Kongoni is less sexually dimorphic than any other species; and in pedicle height it and the Tora Hartebeest are less sexually dimorphic than the other species. The frontal sinuses are also relatively small, without much sexual dimorphism, and penetrate the horns to some degree (though not as much as in the Red Hartebeest, A. caama , or the Lelwel Hartebeest). Like other East African species, the Kongoni can be regarded as belonging to the “lightly armed” group. Its color is pale tawny, with the rump patch only slightly paler; only the tail tuft is black. The preorbital secretion is black and sticky, quite different from the secretion of the Lelwel Hartebeest and Swayne’s Hartebeest.

Habitat. Kongoni live on Themeda triandra grasslands with scrub Acacia such as whistling thorn; this habitat is characterized by warm days (maximum 24-9°C) and cooler nights (minimum 13-7°C), and two annual rainy seasons.

Food and Feeding. The Kongoni is a selective grazer, especially on Themeda triandra, Digitaria macroblephara, and Pennisetum mezianum, which together make up 57% of the dietin the dry season and 70-2% in the wet season. Most of the rest is made up of other leafy perennial grasses. Browse makes up only 3-4% ofthe diet in the dry season and as little as 1-2% in the wet season. Feeding trials show that Kongoniare very selective, taking in 16% less (dry weight) than sympatric wildebeest or topi, but their smaller appetite is compensated by a greater efficiency of digestion of fiber than other ruminants. On the Athi-Kapiti Plains, where they share the habitat with wildebeest, and cattle are also grazed, the diet overlaps a good deal with both other species—by some 80% with the diet of wildebeest and only slightly less with the diet ofcattle. There is more information about the Kongoni than about most other hartebeest species, and it is often notclear to what degree what is known about this species might also be characteristic of the others. For example, the Kongoni is known to have a lower metabolic rate and water consumption than sympatric (East African) wildebeest or topi, but whether this is true of all hartebeest is unclear.

Breeding. A territorial male greets a female with a head-up display and stands blocking her with his ears lowered, then turns slowly to sniff her vulva. Receptive females stand with hindlegsslightly spread, the tail to one side. Gestation is eight months; the female is continually breeding, and frequently has two calves of different ages accompanying her. This extended breeding season is believed to be correlated with the generally low degree of sexual dimorphism in this species, in contrast to some other species, such as the Lelwel Hartebeest. Females move apart from the herd, often along with their previous offspring, to give birth. Calves do not try to stand until nine minutes after birth, and do not stand firmly until 30 minutes, but shortly after that they walk and run. The hiding phase lasts for two weeks. Male calves may accompany their mothers for up to 2.5 years, then they join bachelor herds; they are mature at 3—4 years. This is unlike other Alcelaphini. Although the age of maturity is the same, the young of other species leave their mothers at 1-5 years of age.

Activity patterns. Kongoni tend to migrate between short-grass, well-drained pastures in the rains and long grasses in the dry season. Large congregations may form at these times. Up to 100 males may remain near waterholes in the dry season, breaking up into small groups to graze. Habitable areas are partitioned into a mosaic of permanent or semi-permanent territories, among which move herds of 6-15 females and young.

Movements, Home range and Social organization. The female—young herds, which have well-marked hierarchies within them, have home ranges of 3-7-5-5 km? which will include 20-30 males’ territories. In areas of low population density a herd may stay a long time on a singleterritory, becoming in effect the harem of the territory-holding male. A young male makes an “appeasement ceremony” with a head-in posture, to an adult male, and is thereby allowed to live on the territory within the female herd. Bachelor herds, usually small in size but sometimes including up to 35 individuals, consist of males 1-4 years old; after about three or four years of age, they attempt to gain territories. Bachelor herds have a home range of 6-7-10-3 km? In Nairobi National Park, 33% of adult males hold territories, but one-half of them hold them for less than three months. Territorial boundaries seem fixed, regardless of which male is in occupancy; in Nairobi National Park, they average 31 ha. Within the territory, the center of activity (constituting 10-20% ofthe total area) is more vigorously defended than the rest, and when the male is in this area he will challenge any other male who approaches within a couple of hundred meters. Neighboring males regularly meet at their mutual territorial boundaries and interact with various behaviors, including neck-sliding (standing facing each other, each sliding his head up and down on the other’s neck, transmitting preorbital secretions), sparring, repeated defecation, pawing, and parallel grazing 5-10 m apart. These displays generally last over ten minutes. If a male leaveshisterritory and returns to find another bull has takenit, there may be a serious fight, often lasting more than an hour, the winner chasing the loser a long way. Prime males hold the prime territories. Peripheral territories are partly in scrub grassland, are larger than prime territories, and are less severely congested; indeed they often remain unoccupied.

Status and Conservation. Classified as Least Concern on The IUCN Red List (as A. buselaphus cokii). They remain in good numbers (estimate of 42,000), with nearly threequarters of them in protected areas. Kongoni and Lewlel Hartebeest are, or were, sympatric in much of the Kenya Rift Valley and mixed, perhaps hybrid, populations occur there, although most of these populations are probably now extinct.

Bibliography. Capellini & Gosling (2006), Estes (1991a, 1991b), Farke (2007), Kingdon (1982), Roosevelt & Heller (1914).

Figures

On following pages: 147. Swayne's Hartebeest (Alcelaphus swaynel); 148. Kongoni (Alcelaphus coki); 149. Lichtenstein's Hartebeest (Alcelaphus lichtensteinii); 150. Red Hartebeest (Alcelaphus caama); 151. Herola (Beatragus hunter).

Distribution. S Kenya and N Tanzania ; the distribution extends approximately from Lake Nakuru and S of Mt Kenya , through the S part of Tsavo East National Park, to about the N edge of the Brachystegia zone in N Tanzania , more or less along a line between the coast opposite Zanzibar and the S end of Lake Victoria. There is some evidence that pockets ofthis species occur farther S in suitable areas in the Brachystegia zone that are otherwise the habitat of Lichtenstein’s Hartebeest ( A. lichtensteinii ).