NYALA, Tragelaphus angasii

WHAT IT IS

A dry land, hairier version of a sitatunga, found only in southeastern Africa. Bushbuck body plan, with extreme gender differences. Male wt 216 275 lb. (98 125 kg), ht 42 in (106 cm); Female wt 121 132 lb. (55 60 kg), ht 36 in (92 cm). Horns: 24 to 33 in (60 83 cm) with 1.5 to 2.5 twists. Coat: short in females and young, long in adult males, including fringe from throat to hindquarters and longest spinal crest in the tribe. Color females and young bright chestnut with 8 to 13 contrasting torso stripes, spots and chevrons on chest and head; males dark charcoal gray upper body and limbs, tan lower legs; dark belly fringe and white spinal crest; stripes reduced or absent.

WHERE IT LIVES

Coastal plain of Mozambique and major river valleys extending into Malawi, Zimbabwe, and South Africa; range greatly reduced, especially in Mozambique.

RELATIVES

The so called mountain nyala of the Ethiopian Highlands looks more like a greater kudu. T. angasii is closer to bushbuck and sitatunga.

GOOD PLACES TO SEE IT

Lengwe NP, Malawi; Gonarezhou NP, ZimbaLwe; Hluhluwe GR, Kruger NP, South Africa. Mkuzi NP, South Africa

ECOLOGY

Closely tied to thickets and densely wooded lowlands generally near water, with access to high quality grassland. A grazer/browser.
Grazes fresh green grass during the rains; browses leaves, pods, various fruits, and herbs during the dry season, meanwhile drinking daily.

ACTIVITY

Night and some day. Nyalas spend the day in or near cover, emerging at night to feed in grassland. During spring and summer months they spend the hottest hours in deep cover, typically standing motionless and almost invisible beside a tree. During cooler winter days they rest in light shade in the open. Most nyalas are inactive between midnight and dawn.

SOCIAL/MATING SYSTEM

The basic social unit is a female with her latest and next to latest offspring. Herds consist of 2 or more units, which in Natal's Hluhluwe GR typically number 5 to 6 nyalas. Only females guarding hidden calves stay alone. Although herds appear temporary and fluid, daughters tend to stay home and continue associating with their mothers after becoming mothers themselves. Female home ranges in Hlohluwe average 171 acres (range 124-259 acres 150-105 ha); male ranges average 207 acres (124-360 acres [50-146 ha]). Each range includes at least 10% forest and up to 28% open floodplain or other grassland.
Males 1.5 to 3 years old associate but even more casually than females, in twos and threes, rarely up to 9 males, and herd membership seldom remains unchanged for even 2 hours. Males become more solitary as they mature in their sixth year. The sexes stay segregated except when an estrous female is located, or when nyalas aggregate (up to 30, rarely up to 100) on a green pasture, at water holes, or fruiting trees.

REPRODUCTION

Year round with conception peaks in spring and autumn. Estrus lasts 2 days, but females fend off suitors until final 6 hours. Females calve 7 months later, ovulate again within a week, but usually conceive only on the third try (3 week cycle).

OFFSPRING AND MATERNAL CARE

Calves hide 10 to 18 days. Yearlings often remain with their mothers after the next calf is born, but courting males drive adolescent males away when mothers reenter estrus.

PREDATORS

Lion, spotted hyena, leopard, and wild dog.

DIFFERENCES IN NYALA BEHAVIOR

Expect to see and hear Usual context and meaning

Advertising Dominance

Soil horning. males advertise aggressiveness by digging and tossing , soil, preferably soft and wet; also horn and rub forehead on bushes.

Approach in skiff, deliberate manner, lifting legs high. Prelude to broadside display.

Broadside display, with head low and dorsal crest raised performed at variable intensity. Most spectacular display in the tribe; fringe and crest increase apparent size by 40%. male that displays at highest intensity, with fluffed tail draped over rump and movements frozen always wins.

Submission

Lowering crest and turning away. Loser of display duel.

Displacement Activities

Pretended feeding, scraping with incisors, sideswiping, head flagging while backing away, alarm snorting. Performed by losers during display duels.

Courtship

MALE BEHAVIOR

Urine testing. Performed only when checking estrous female; routine checking consists of sniffing the female’s tail.

Nuzzling udder. male pushes muzzle between female’s hind legs, sometimes lifts her hindquarters.

FEMALE BEHAVIOR

Standing in head low or head low /chin out posture. Signals readiness for mounting. Courting male sometimes tries to mount female? that is simply drinking, apparently regarding drinking posture as an invitation.

Female uttering faint clicks while moving away. Significance unclear.
Reprinted from "The Safari Companion" by Richard Estes
nature@nature-wildlife.com