Nyala live in groups of up to 10 individuals that may be mixed or may contain only females or only males. Old males usually live alone. Females often remain near their mothers when they have their offspring, so the relationships in female herds may be considered relatively closer than that of males. Herds usually feed and drink water together. Nyala are not territorial animals and the home ranges of males are approximately equal to that of females and overlap extensively. Nyala are active mainly in the early morning and late afternoon. They browse during the day if temperatures are 20-30 °C (68-86 °F) and during the night in the rainy season.
During the hot hours of the day, these antelopes usually rest in thick bushes. They are very shy in nature, and like remaining hidden rather than coming out in the open. Most sightings of nyala in the wild are at water holes. But nowadays they are becoming less shy and often come out in the sight of tourists. Alert and wary in nature, nyala uses a sharp, high, dog-like bark to warn others in a group about the danger. This feature is mainly used by females. They also react to the alarm calls of impala, baboon, and kudu.
Nyala are polygynous meaning that one male mates with more than one female. They breed throughout the year with the peak in spring and autumn. The males fight over dominance during the mating season and when the male enters a female's herd, he makes a display by raising his white dorsal crest, lowering his horns, and moving stiffly. The female gives birth to a single calf after the gestation period of 7 months. Birth takes place generally away from the sight of predators, in places such as a thicket. The calf remains hidden for up to 18 days, and the mother nurses it at regular intervals. The young usually remains with its mother until the birth of the next calf, during which males in rut drive it away from the mother. Females reach reproductive maturity at 11 to 12 months of age and males start to breed when they are 18 months old.
The coat of the nyala is rusty or rufous brown in females and juveniles. It grows a dark brown or slate grey in adult males, often with a bluish tinge. Females and young males have ten or more white vertical stripes on their sides. Other markings are visible on the face, throat, flanks, and thighs. Stripes are very reduced or absent in older males. Both males and females have a white chevron between their eyes and a bushy tail white underside. Both sexes have a dorsal crest of hair running right from the back of the head to the end of the tail. Males have another line of hair along the midline of their chest and belly. Only the males have horns. Horns are 60-83 cm (24-33 in) long and yellow-tipped. There are one or two twists. The spoor is similar to that of the bushbuck, but larger. It is 5-6 cm (2-2.4 in) long. The nyala has hairy glands on its feet, which leave their scent wherever it walks.
Nyala are found across southeast Africa from the Lower Shire Valley in Malawi through Mozambique and Zimbabwe to eastern South Africa and Swaziland. They inhabit dense lowland woodlands, thickets, and lush green river country. They choose places with good quality grasslands as well as the provision of fresh water.
