It was first described in 1849 by George French Angas and exhibits the highest sexual dimorphism among the spiral-horned antelopes.

As its population is relatively stable, it has been listed as of least concern by the International Union for Conservation of Nature.

As a herbivore, the nyala feeds upon foliage, fruits and grasses, and requires sufficient fresh water.

The principal threats to the species are illegal poaching and habitat loss resulting from human settlement and livestock grazing.

However, the large-horned, impressive males are highly prized as game animals by sport hunters.

It was re-erected as a valid genus in 2011 under the classification of Peter Grubb and Colin Groves,[8] but has not been embraced by taxonomic authorities such as the Mammal Diversity Database.

[3][9] Among its closest extant relatives are the forest-inhabiting bongo, the bushbuck, the large common and giant elands, the greater and lesser kudus, the mountain nyala (of Ethiopia) and the swamp-dwelling sitatunga, all of which share similar characteristics, such as hornless females, vertical side-stripes and other unique white markings, and the spiraling horns and distinct "beard" or dewlap of males, often with a raised trail of fur extending down the back and underside.

[citation needed] In 2005, Sandi Willows-Munro (of the University of KwaZulu-Natal) and colleagues carried out a mitochondrial DNA analysis of the nine Tragelaphus species.

The results showed the tribe Tragelaphini to be monophyletic, with the lesser kudu (T.  imberbis) basal in the phylogeny, followed by the nyala.

[10][11] On the basis of mitochondrial data, studies have estimated that the lesser kudu separated from its sister clade around 13.7 million years ago.

[15] Fossil evidence suggests that the nyala has been a separate species since the end of the Miocene (5.8 million years ago).

Genetic evidence suggests that the proto-nyala had some early hybridization with the proto-lesser kudu, but the two have remained separate long after this crossing.

It grows a dark brown or slate grey in adult males, often with a bluish tinge.

Both sexes have a dorsal crest of hair running right from the back of the head to the end of the tail.

[20] During an attempt of blood sampling in the nyala, it was found that Vitamin E levels varied during stress.

The methods used were polymerase chain reaction (PCR) and reverse line blot (RLB) hybridization.

[24] Also, a trypanosome was isolated from a nyala, wild-caught in Mozambique, which was diagnosed and found as akin to Trypanosoma vivax, based on biological, morphological and molecular data.

Necrosis (that is, the premature death of cells in a living tissue) and mineralization were found in the skeletal muscle after a histological analysis.

[17][30] Alert and wary in nature, the nyala use a sharp, high, dog-like bark to warn others in a group of danger.

[17] A study in Zululand showed that the nyala fed mainly in the early morning and the late afternoon.

As the rainy season arrived, both species took to a diet of mainly monocotyledons, and the impala consumed more of them.

It was found that females spent equal periods of time foraging in all the three habitats, but males preferred sand forest more.

More differences were noted, as males ate woody species at a greater average height whereas females fed from the low herbaceous layer.

When the male enters a females' herd during mating, he makes a display by raising his white dorsal crest, lowering his horns and moving stiffly.

[17] The kidney fat indices (KFIs) of impalas and nyalas have been studied to understand the influence of social class and reproduction on them.

[17] The nyala inhabits dense lowland woodlands and thickets, mainly in southern Malawi, Mozambique, Zimbabwe, and eastern South Africa.

According to a study of nyala in South Africa, Mozambique, Malawi and Zimbabwe, there was a marked difference in the gene frequencies at three microsatellite loci.

Thus, the geographic variation in the nyala may be due to a distribution pattern based on habitat specificity.

[29] The home ranges of males are approximately equal to that of females, about 10 square kilometres (3.9 sq mi) in area.

[29] The major threats to the population of the nyala are poaching, habitat loss, agriculture and cattle grazing.