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Tragelaphus angasii
nyala


By Deborah Ciszek

Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Mammalia
Order: Artiodactyla
Family: Bovidae
Genus: Tragelaphus
Species: Tragelaphus angasii

Geographic Range

Nyala have a localized distribution, occupying some parts of southeastern Africa.

Biogeographic Regions
ethiopian (Native )

Habitat

Nyala are found near thickets in dry savanna woodland, and prefer proximity to high quality grassland and fresh water as well.

Terrestrial Biomes
savanna or grassland ; scrub forest

Physical Description

Range mass
55 to 126 kg
(121.15 to 277.53 lb)

Nyala are medium sized in comparison to other antelopes, with a marked size difference between the sexes. Males weigh 98-125 kg and stand over one meter tall at the shoulder, while females weigh 55-68 kg and are slightly less than a meter tall. Males have horns, which can be up to 80 cm long and spiral upwards, curving out at the first turn. Females and juveniles are usually a rusty red color, but adult males become slate gray. Both males and females have a dorsal crest of long hair that runs from the back of the head to the base of the tail, and males additionally have a fringe of long hair along the midline of their chest and belly. Nyala have some white vertical stripes and spots, the pattern of which varies.

Reproduction

Range number of offspring
1 to 2

Average number of offspring
1

Average number of offspring
1
[External Source: AnAge]

Range gestation period
7.33 to 8.4 months

Average birth mass
5232.5 g
(184.41 oz)
[External Source: AnAge]

Average weaning age
7 months

Average age at sexual or reproductive maturity (female)
Sex: female

452 days
[External Source: AnAge]

Nyala can breed at any time of the year, but there is a breeding peak in the spring and a smaller peak in the autumn. A female's estus cycle is about 19 days long. Males court females for two days of this cycle, but females are receptive to mating for only 6 hours per cycle. Gestation takes 7 months, after which a single, 5 kg calf is born. The young are born out of the sight of potential predators (lions, hyenas, leopards, wild dogs) in a thicket. A calf remains hidden for up to 18 days, during which time the mother returns periodically to clean and nurse it. Offspring remain with their mothers until her next calf is born, but after that courting males drive adolescent males away from their mothers.

Parental Investment
altricial ; post-independence association with parents

Lifespan/Longevity

Average lifespan
Status: captivity

18.5 years
[External Source: AnAge]

Behavior

Nyala are gregarious, generally staying in groups of two to 30 individuals. Females sometimes remain near their mothers after they have offspring themselves, so relatedness within female groups may be relatively high. Males also form groups, but these associations are much more transitory, with no long term association between particular males. The species is not territorial, and home ranges often overlap. Larger numbers of individuals may come together at a good feeding site or a water source. Adult males fight when in the presence of a female in estrus. A male displays to another male by raising his dorsal crest of white hair, holding his head high, and raising his tail. If aggression occurs it may be violent; males have been known to be killed by a thrust of their adversary's horns. Generally it is the larger of two males that is the victor and subsequently mates with the female. This species has a variety of stereotyped behaviors associated with dominance interactions and courtship.

Nyala may be active during the day, but it is more common that their activities are concentrated in the evening and night. They spend much of the day concealed in brush, particularly the hottest part of the day. They are vulnerable to several predators, and members of female groups give an alarm call, a deep barking vocalization that results in the flight of other nyala within hearing range. They also react to the alarm calls of several other species - impala, baboons, and kudu. Impala react to the alarm call of the nyala as well. Nyala sometimes follow feeding baboons, taking advantage of the fruits and leaves that the baboons dislodge from trees.

Key Behaviors
social

Food Habits

These antelope both graze and browse. They eat the leaves, twigs, flowers and fruits of many different species of plants. During the rainy season they mainly eat the fresh green grass. They drink daily when water is available, but they can survive in areas where water is only available seasonally.

Economic Importance for Humans: Positive

These antelopes have probably historically been hunted as food animals.

Positive Impacts
food

Conservation Status

IUCN Red List of Threatened Species [Link]
Least Concern
More Information

US Federal List [Link]
No special status

CITES [Link]
No special status

Nyala currently have a more limited distribution than they have had in the past. Recently in some areas their habitat has actually been improved through human activities, such as shifting agricultural techniques resulting in abandonment of fields and subsequent bush encroachment, and overgrazing of grasslands by cattle, which results in invasion by many herbs that nyala eat.

For More Information

Find Tragelaphus angasii information at

Contributors

Deborah Ciszek (author), University of Michigan.

References

Estes, R.D. 1993. The Safari Companion. Chelsea Green Publishing Co., Post Mills, Vermont.

Skinner, J.D. and R.H.N. Smithers. 1990. The Mammals of the Southern African Subregion. University of Pretoria, South Africa.

To cite this page: Ciszek, D. 1999. "Tragelaphus angasii" (On-line), Animal Diversity Web. Accessed May 23, 2012 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Tragelaphus_angasii.html

Disclaimer: The Animal Diversity Web is an educational resource written largely by and for college students. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.

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