Common Waterbuck, Kobus ellipsiprymnus

Other Waterbuck - Defassa, (Kobus defassa)

WHAT IT IS

A big, shaggy antelope, females somewhat resembling deer. Stocky build, with long body and neck, male wt 520 lb (236 kg), ht 51 in (127 cm); female wt 409 lb (186 kg), ht 48 in (119 cm). Horns: 22 to 39 in (55-99 cm), tips curved forward, thick and deeply ridged. Coat: coarse-haired with a neck mane and ruff. Color: grizzled red-brown; lower legs black; white rump patch (defassa waterbuck) or elliptical ring around the rump (common waterbuck); white under parts, throat, hair inside ears, eyebrow line, and snout; males darken with age. Scent glanced Lacks usual scent glands but greasy coat emits musky smell.

WHERE IT LIVES

Northern and Southern Savanna. Defassa waterbuck lives west of the Rift, Luangwa, and middle Zambesi valleys; common race occurs in these valleys to the eastern seaboard. Hybrids occur where the two races overlap, as in Nairobi NP and Tanzania's Ngorongoro Crater.

GOOD PLACES TO SEE IT

Nakuru and Meru NP, Kenya; Moyowosi GR, Serervrti NP, Tanzania; Akagera NP, Rwanda; Queen Elizabeth and Murchi- son falls NP Uganda; Kafue and Luangwa NP Zambia; Zambezi and Mana Pools Zimbabwe; Kruger NP Umfolozi-Hluhluwe GK South Africa.

ECOLOGY

Living up to its name, the waterbuck has even less tolerance for dehydration than domestic cattle and has to stay within a few miles of water to drink every day or two. An edge species, it prefers grassland and firm guided adjacent to woodland. Habitats meeting all these requirements occur along drainage lines and within valleys, causing the typically patchy distribution of waterbuck. A grazer on medium and short grasses rich in protein; also eats herbs and foliage when green grass unavailable.

ACTIVITY

Day and night. Foraging and resting times vary widely, reflecting seasonal and latitudinal differences, variations in pasture quality and growth stage, distance from water, sex, age, reproductive status. and predation pressure.

SOCIAL/MATING SYSTEM

Sedentary and territorial but unusual in that bachelor males, which share the limited patches of suitable habitat with females and young, are tolerated close to and even in female herds by some territorial males. As long as they grovel on command, a territory owner may permit even adult males to reside on his property. Regular performance of an appeasement ceremony featuring the same submissive displays performed by females and young is the quid pro quo that enables up to 3 adult males to give as satellites-with occasional opportunities to sneak copulations and fair prospects of inheriting the territory. Females associate so casually and range singly so often that one researcher decided waterbuck herds (typically 5 to 10 but up to 70 animals) consist of essentially independent individuals whose home ranges happen to overlap. Cows come and go, there is no established rank order or regular leader and no greeting ceremony or social grooming. Yet the same expert noted a positive social attraction between females, aggressive treatment of outsiders, and a tendency of certain cows to associate. Bachelor herds (average 5. up to 40 males) are exclusive and subject to a strict rank order although herd composition also changes hourly as members come and go. Male calves may be forced to join the bachelor contingent at 8 to 9 months, soon after their horns appear, remaining there until mature at 6 years. Home ranges and territories vary in size, depending on the extent of preferred habitat, population density, and age (old animals have smaller ranges and territories than prime animals). In Queen Elizabeth NP, 10 cows had average home ranges of about 1500 acres (600 ha), a bachelor herd's range was 250 acres (100 ha), and territories were 133 to 557 acres (average 360 acres (146 ha)

HOW IT MOVES

Lacking speed and endurance, the waterbuck depends on cover as a refuge from predators such as hyenas and wild dogs. Trotting is an important gait; alarmed waterbucks both style-trot and stot.

REPRODUCTION

Year-round near equator; once a year in higher latitudes, calving during rainy season. Gestation 8 to 8.5 months. Cows may calve at 10-month intervals, but rarely conceive before 3.

OFFSPRING AND PARENTAL CARE

Females seek cover a couple days before calving, preferably in same locale they calved previously. Mother goes up to 550 yds from her calf's hiding place by day but stays close at night, retrieves and suckles it 3 times/day during 2 to 4 week hiding stage. Juveniles are often seen alone or in unattended creches. Weaning complete at 6 to 8 months.

PREDATORS

Mainly spotted hyena, lion, leopard, and wild dog-the last 2 mainly on young, Waterbucks are thought to take refuge in cover at night, and mothers of young calves frequent woodland.

Territorial Advertising

Biggest, darkest male with longest horns is the likely territory owner; to make sure, watch for interactions between males.

Aggression

High-horn and angle-horn threat; neck arched, mil out, curved to side or up.

Submission

Head-low chin-out posture, tail out with champing. > Submissive response to aggression, including chewing movements.

Courtship

MALE BEHAVIOR

Resting chin on female's rump. Mounting intention.

FEMALE BEHAVIOR

Champing. Submissive response to male.
Sniffing males's horns and penis. Receptive behavior.

Mother and Offspring

Mother summons hidden calf with bleat or moo.