Perception Channels: tactile ; chemical
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.
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
These antelopes have probably historically been hunted as food animals.
Positive Impacts: food
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.
Nyala have a localized distribution, occupying some parts of southeastern Africa.
Biogeographic Regions: ethiopian (Native )
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
Average lifespan
Status: captivity: 18.5 years.
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.
Range mass: 55 to 126 kg.
Other Physical Features: endothermic ; bilateral symmetry
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.
Range number of offspring: 1 to 2.
Average number of offspring: 1.
Range gestation period: 7.33 to 8.4 months.
Average weaning age: 7 months.
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); sexual
Average birth mass: 5232.5 g.
Average number of offspring: 1.
Average age at sexual or reproductive maturity (female)
Sex: female: 452 days.
Parental Investment: altricial ; post-independence association with parents
Nyala (Tragelaphus angasii) are a species of large antelope that reside in South Eastern Africa. Nyala have an average lifespan of 16 years (Castello, 2016). Adult nyala can weigh anywhere from 100 to 158.4 kg (220 to 348 lbs), with females weighing an average of 40% less than their male counterparts. The potential weight of nyala varies in response to the season and/or the current population size. Nyala are extremely sexually dimorphic. Females and adolescent males have a short, reddish coat with ten or more white stripes on their sides. These white stripes are progressively lost in males as they mature.
Males are much larger with spiraling horns that are not present in females. These horns can fully spiral anywhere from 1–1 ½ times and are typically longer than 500 mm in adults, though they can grow up to 835 mm. Despite these extravagant horns, male nyala establish dominance through exuberant displays and rituals rather than actual fighting. Fighting between males is extremely rare, and the primary use of the spiraling horns seems to be plowing the ground. Many male nyala, both adult and adolescent, have been witnessed digging into the ground with their horns. This is particularly common around watering holes (Tello & Van Geller, 1975).
Males also have a large, shaggy mane on their neck and the underside of their body that the females lack. The mane beneath their hips is unique to this species and has not been witnessed occurring in any other antelope. Adult males have a dark brown fur coat that usually covers the white stripes present on their sides. It takes approximately a year for females to mature, and 18 months for males (Castello, 2016). Nyala are native to Malawi, Mozambique, South Africa, Swaziland, and Zimbabwe. They have also been introduced to Botswana, due to their introduction to farms in adjacent regions, and to Namibia. In the 1950s nyala went extinct in Swaziland, but have since been successfully reintroduced (Castello, 2016).
Nyala prefer to reside in thick brush for the majority of the day, emerging in the early morning and in the late afternoon. They are very cautious about traveling through wide open clearings, and when they sense a predator they give a deep, dog-like bark before dashing back into the thickets. Nyala travel in troops that can be comprised of anywhere from 2-10 individuals. These troops can be both single-sex and mixed. Typically, older males are solitary. Nyala are not particularly territorial, and often multiple troops will have heavily overlapping ranges without incident (Castello, 2016).
The main predators of adult nyala are leopards and lions, while the juveniles face predation from baboons and raptorial birds (Trell, Van Geller, 1975). Cape hunting dogs are a threat to nyala of all ages, as they also share the SE corner of the African continent that the nyala populate. 80% of all known nyala live on South African protected areas, with the majority of the rest residing on private land. They are most prevalent in South Africa, where they are bred to meet the high demand for male nyala as trophies and a source of meat. This high demand has made them a staple of Africa’s tourism, and careful conservation of the species has led to the species being labeled one of least concern in terms of threat of extinction. However, it has also been determined that Nyala in particular are vulnerable to the looming threat of global warming. This is because a pillar of their diet, Urocloa mozambicensis, dries up and dies quickly during periods of drought like those that would be associated with the predicted warming climate (Kazembe, 2009). While global warming may cause their numbers to dwindle, the aforementioned plant is not their only food source and it is unlikely its loss would drive them to extinction. Nyala eat vegetation from more than a hundred different species of plants, consuming leaves, fruits, flowers, and even high-lignin content items like twigs and bark (Tello, Van Geller, 1975).
The lowland nyala or simply nyala (Tragelaphus angasii),[3] is a spiral-horned antelope native to southern Africa. It is a species of the family Bovidae and genus Tragelaphus, previously placed in genus Nyala. It was first described in 1849 by George French Angas. The body length is 135–195 cm (53–77 in), and it weighs 55–140 kg (121–309 lb). The coat is maroon or rufous brown in females and juveniles, but grows a dark brown or slate grey, often tinged with blue, in adult males. Females and young males have ten or more white stripes on their sides. Only males have horns, 60–83 cm (24–33 in) long and yellow-tipped. It exhibits the highest sexual dimorphism among the spiral-horned antelopes. It is not to be confused with the endangered mountain nyala living in the Bale region of Ethiopia).
The nyala is mainly active in the early morning and the late afternoon. It generally browses during the day if temperatures are 20–30 °C (68–86 °F) and during the night in the rainy season. As a herbivore, the nyala feeds upon foliage, fruits and grasses, and requires sufficient fresh water. A shy animal, it prefers water holes rather than open spaces. The nyala does not show signs of territoriality, and individuals' areas can overlap. They are very cautious creatures. They live in single-sex or mixed family groups of up to 10 individuals, but old males live alone. They inhabit thickets within dense and dry savanna woodlands. The main predators of the nyala are lion, leopard and African wild dog, while baboons and raptorial birds prey on juveniles. Mating peaks during spring and autumn. Males and females are sexually mature at 18 and 11–12 months of age respectively, though they are socially immature until five years old. After a gestational period of seven months, a single calf is born.
The nyala's range includes Malawi, Mozambique, South Africa, Eswatini, Zambia, and Zimbabwe. It has been introduced to Botswana and Namibia, and reintroduced to Eswatini, where it had been extinct since the 1950s. Its population is stable, and it has been listed as of least concern by the International Union for Conservation of Nature. The principal threats to the species are poaching and habitat loss resulting from human settlement. The males are highly prized as game animals in Africa.
Lowland nyala
Phylogenetic relationships of the mountain nyala from combined analysis of all molecular data (Willows-Munro et.al. 2005)The nyala was first described by George French Angas, an English naturalist, in 1849. The scientific name of nyala is Tragelaphus angasii. The name angasii is attributed to Angas, who said that John Edward Gray had named this species after Angas' father, George Fife Angas of South Australia. According to Article 50.1.1 of the International Code of Zoological Nomenclature and International Commission on Zoological Nomenclature, though, this is insufficient to state Gray as the author.[4] The name "nyala" is the Tsonga name for this antelope, which is likely the source of the English, along with Zulu inyala.[5] Its first known use was in 1899. The word has a Bantu origin, similar to the Venda word dzì-nyálà (nyala buck).[6]
The nyala is the second taxon to branch off from the tragelaphine family tree just after the lesser kudu. As the nyala line has remained separate for a considerable time (over 5 million years), some authorities have placed it in its own monotypic genus Nyala. Nyala was proposed in 1912 by American zoologist Edmund Heller, who also proposed Ammelaphus for the lesser kudu,[7] but it was not widely recognized. 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]
In 2005, Sandi Willows-Munro (of the University of KwaZulu-Natal) and colleagues carried out a mitochondrial DNA analysis of the nine Tragelaphus species. Mitochondrial DNA and nuclear DNA data were compared. 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. However, nuclear DNA data shows lesser kudu and nyala forming a clade, which collectively separated from the sister clade 13.8 million years ago.[12][13]
The nyala has 55 male chromosomes and 56 female chromosomes.[14] The Y chromosome has been translocated onto the 14th chromosome, as in other tragelaphids, but no inversion of the Y chromosome occurs.[4] Cranial studies have shown that the mountain nyala and nyala, though sharing a common name, are actually distant relatives.[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.[4]
The nyala is a spiral-horned and middle-sized antelope, between a bushbuck and a kudu.[16] It is considered the most sexually dimorphic antelope.[2] The nyala is typically between 135–195 cm (53–77 in) in head-and-body length.[2] The male stands up to 110 cm (43 in), the female is up to 90 cm (3.0 ft) tall. Males weigh 98–125 kg (216–276 lb), while females weigh 55–68 kg (121–150 lb). Life expectancy of the nyala is about 19 years.[17]
The coat 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.[2] 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 40–55 cm (16–22 in) long 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.[17][18]
Only the males have horns. Horns are 60–83 cm (24–33 in) long and yellow-tipped. There are one or two twists.[2] The spoor is similar to that of the bushbuck, but larger. It is 5–6 cm (2.0–2.4 in) long. The feces resemble round to spherical pellets.[19] The nyala has hairy glands on its feet, which leave their scent wherever it walks.[3]
The condition of the nyala often varies between the sexes. According to a study, this can be attributed to the differences in their body sizes. It was noted that during nutritional stress, old adults died in more numbers, of which most were males.[20] During an attempt of blood sampling in the nyala, it was found that Vitamin E levels varied during stress.[21]
A study of the helminths from 77 nyalas from four game reserves in Natal revealed the presence of ten nematode species and four nematode genera, a trematode species and paramphistomes (members of superfamily Paramphistomoidea), and two cestode genera. The research discovered new parasites that the nyala was host of - namely a Cooperia rotundispiculum race, Gaigeria pachyscelis, a Gongylonema species, Haemonchus vegliai, Impalaia tuberculata, an Oesophagostomum species, a Setaria species, Trichostrongylus deflexus, Trichostrongylus falculatus, the larval stage of a Taenia species, a Thysaniezia species and Schistosoma mattheei. Ostertagia harrisi and C. rotundispiculum were the most dominant nematodes in the antelope.[22]
Another study of 97 blood samples of South African nyalas revealed the presence of tick-borne hemoparasites (blood parasites). The methods used were polymerase chain reaction (PCR) and reverse line blot (RLB) hybridization. The dominant parasites were Theileria species, T. buffeli, T. bicornis, Ehrlichia species, Anaplasma marginale and A. bovis.[23] Ten tick species, two louse species and a louse fly species were recovered in a study of 73 nyalas at Umfolozi, Mkuzi and Ndumu Game Reserves in northeastern KwaZulu-Natal in 1983 and 1984 and an additional six individuals in 1994. It was found that nyalas were hosts to all stages of development in Boophilus decoloratus, Rhipicephalus appendiculatus and R. muehlensi and the immature stages of Amblyomma hebraeum and Rhipicephalus maculatus. Adult males served hosts to more number of ticks and lice than adult females did.[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.[25]
The nyala can also suffer from myopathy. In between January 1973 and June 1981, 21 nyalas succumbed to the disease. The main symptoms were stiffness, inability to rise, and failure to suckle in newborns. Necrosis (that is, the premature death of cells in a living tissue) and mineralization were found in the skeletal muscle after a histological analysis. In the juveniles there was acute necrosis of the cardiac muscle. In adults, there was interstitial fibrosis of the cardiac muscle, along with arteriosclerosis.[26]
In a report published in 1994 entitled "Epidemiological observations on spongiform encephalopathies in captive wild animals in the British Isles", it was noted that spongiform encephalopathy had been diagnosed in one nyala captive in a zoo.[27] The nyala was formerly affected by the disease rinderpest, although the viral disease is considered eradicated now.[28]
The nyala is active mainly in the early morning and late afternoon. It browses during the day if temperatures are 20–30 °C (68–86 °F) and during the night in rainy season.[29] These antelopes rest in thick bushes during the hot hours of the day.[2] The nyala is very shy and cautious in nature, and often remains hidden rather than coming out in the open. Most sightings of the nyala in the wild are at water holes.[2] But in protected areas they become less shy and often come out in view of tourists.[3]
Nyala groups are according to sex or mixed. Herds usually browse and drink water together.[16] Each group consists of two to ten individuals. A study in Zinave National Park at Mozambique showed that 67% of the observations were of groups of one to three nyalas, and the rest of the herds consisted of up to 30 nyalas. Herds often broke up and re-formed.[29] Generally adult males remain alone. Females often remain near their mothers when they have their offspring, so the relationships in female herds may be closer than those of males.[17][30]
Alert and wary in nature, the nyala use a sharp, high, dog-like bark to warn others in a group of danger. This feature is mainly used by females.[17] They also react to the alarm calls of impala, baboon and kudu. The impala has been found to react to the calls of the nyala as well.[17] The main predators of nyala are lion, leopard, cheetah, spotted hyena, African wild dog and nile crocodile while baboons and raptorial birds are predators of juveniles.[29][31]
As a herbivore, the nyala's diet consists of foliage, fruits, flowers and twigs. During the rainy season they feed upon the fresh grass. They need a regular intake of water, and thus choose places with a water source nearby. However, they are adapted to live in areas with only a seasonal availability of water.[17] A study in Zululand showed that the nyala fed mainly in the early morning and the late afternoon.[32] They feed at night during the rainy season.[31]
A study in Mkhuze Game Reserve and Ndumu Game Reserve in Natal focused on the dietary habits of the impala and the nyala showed that the amount of dicotyledons in their diets varied seasonally. In the dry season, the nyala's dicotyledon diet content was 83.2% and the impala's 52%. In this season, the diet grew richer in fiber and dietary proteins were less. The reverse occurred in the rainy season. As the rainy season arrived, both species took to a diet of mainly monocotyledons, and the impala consumed more of them. The diet contained more proteins than fiber.[33]
Another study was done to find whether the sexual dimorphism in the nyala influenced its foraging habits. Vegetation surveys were conducted with the end of each feeding bout. 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. It was concluded that the differences resulted from varying nutritional and energetic demands according to their diverse body sizes and differing reproductive strategies.[34]
_young_male_2w.jpg)
The nyala breeds throughout the year, but mating peaks in spring and autumn. The reason for this is still unknown, but attributed to the photoperiod and the feeding habits of the animal.[35] Females reach sexual maturity at 11 to 12 months of age and males at 18 months (though they are socially immature until five years old),[2] though they begin to show active spermatogenesis at 14 months.[36]
Before ovulation, the Graafian follicles reach a length of at least 6.7 cm (2.6 in).[36] A female's estrous cycle is about 19 days long. Males will attempt to mate with the female for two days of the cycle, but she allows it for only six hours per cycle. 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. As in many other animals, the males fight over dominance during mating.[17]
The kidney fat indices (KFIs) of impalas and nyalas have been studied to understand the influence of social class and reproduction on them. To determine the KFI, the kidney is removed and weighed with the fat and once again excluding the fat. The resultant difference is the amount of fat on the kidney. The more the fat, the healthier the animal.[37] In rut, male nyalas had lower KFIs, which did not vary much with the season. Pregnant females of both nyala and impala had higher KFIs than non-pregnant ones.[38]
There is a significant increase in corpus luteum in the last third of gestation.[36] Gestation is of seven months. A single calf is born, weighing 5 kg (11 lb). 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 calf remains with its mother until the birth of the next calf, during which males in rut drive it away from the mother.[17]
The nyala inhabits dense lowland woodlands and thickets, mainly in southern Malawi, Mozambique, Zimbabwe, and eastern South Africa. It chooses places with good quality grasslands as well as provision of fresh water.[17] It also inhabits lush green river country.[3] The nyala's natural range stretches across southeast Africa from the Lower Shire Valley in Malawi through Mozambique and Zimbabwe to eastern South Africa and Eswatini.[28]
The geographic distribution of the nyala may be based on the genetic variation. 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. Mitochondrial DNA analysis revealed the presence of a unique haplotype in individuals from each location. Thus, the geographic variation in the nyala may be due to a distribution pattern based on habitat specificity.[39]
Today nyala are found in South African protected areas in the Ndumo Game Reserve, uMkuze Game Reserve and Hluhluwe-Umfolozi Game Reserve, all in KwaZulu-Natal, as well as in Kruger National Park. As of 1999, 10–15% of nyala occurred on private land. Efforts are being made to retain the populations of nyala in Gorongosa National Park and Banhine National Park in Mozambique.[28] Nyala also thrive in Lengwe National Park in Malawi.
Nyala have never been observed showing territoriality. Territories of either sex overlap extensively.[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.[28] Rinderpest outbreaks have also contributed in population loss.[28] This species is currently of Least Concern, and the population is considered stable by both the IUCN and CITES.[15] As of 1999, the total population of the nyala was around 32,000 individuals. More recent estimates show that South Africa has at least 30,000 nyalas, with 25,000 in KwaZulu-Natal. There are now more than 1,000 on protected areas and ranches in Eswatini. In Mozambique there are not more than 3,000, in Zimbabwe over 1,000, and numbers in Malawi have fallen from 3,000 to about 1,500. Namibia has the smallest population, at about 250.[28]
Today over 80% of the total population is protected in national parks and sanctuaries, mostly in South African protected areas. In South Africa there is a high demand for adult males as game trophies.[28]
The lowland nyala or simply nyala (Tragelaphus angasii), is a spiral-horned antelope native to southern Africa. It is a species of the family Bovidae and genus Tragelaphus, previously placed in genus Nyala. It was first described in 1849 by George French Angas. The body length is 135–195 cm (53–77 in), and it weighs 55–140 kg (121–309 lb). The coat is maroon or rufous brown in females and juveniles, but grows a dark brown or slate grey, often tinged with blue, in adult males. Females and young males have ten or more white stripes on their sides. Only males have horns, 60–83 cm (24–33 in) long and yellow-tipped. It exhibits the highest sexual dimorphism among the spiral-horned antelopes. It is not to be confused with the endangered mountain nyala living in the Bale region of Ethiopia).
The nyala is mainly active in the early morning and the late afternoon. It generally browses during the day if temperatures are 20–30 °C (68–86 °F) and during the night in the rainy season. As a herbivore, the nyala feeds upon foliage, fruits and grasses, and requires sufficient fresh water. A shy animal, it prefers water holes rather than open spaces. The nyala does not show signs of territoriality, and individuals' areas can overlap. They are very cautious creatures. They live in single-sex or mixed family groups of up to 10 individuals, but old males live alone. They inhabit thickets within dense and dry savanna woodlands. The main predators of the nyala are lion, leopard and African wild dog, while baboons and raptorial birds prey on juveniles. Mating peaks during spring and autumn. Males and females are sexually mature at 18 and 11–12 months of age respectively, though they are socially immature until five years old. After a gestational period of seven months, a single calf is born.
The nyala's range includes Malawi, Mozambique, South Africa, Eswatini, Zambia, and Zimbabwe. It has been introduced to Botswana and Namibia, and reintroduced to Eswatini, where it had been extinct since the 1950s. Its population is stable, and it has been listed as of least concern by the International Union for Conservation of Nature. The principal threats to the species are poaching and habitat loss resulting from human settlement. The males are highly prized as game animals in Africa.
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