Mountain nyala

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Mountain nyala
Male
Female
both Bale Mountains National Park, Ethiopia
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Family: Bovidae
Subfamily: Bovinae
Genus: Tragelaphus
Species:
T. buxtoni
Binomial name
Tragelaphus buxtoni
(Lydekker, 1910)
juvenile
young male

The mountain nyala (

described by English naturalist Richard Lydekker in 1910. The males are typically 120–135 cm (47–53 in) tall while females stand 90–100 cm (35–39 in) at the shoulder. Males weigh 180–300 kg (400–660 lb) and females weigh 150–200 kg (330–440 lb). The coat is grey to brown, marked with two to five poorly defined white strips extending from the back to the underside, and a row of six to ten white spots. White markings are present on the face, throat and legs as well. Males have a short dark erect crest, about 10 cm (3.9 in) high, running along the middle of the back. Only males possess horns
.

The mountain nyala are shy and elusive towards human beings. Four to five individuals may congregate for short intervals of time to form small herds. Males are not

sexually mature by that time. Gestation
lasts for eight to nine months, after which a single calf is born. The lifespan of a mountain nyala is around 15 to 20 years.

The typical habitat for the mountain nyala is composed of montane woodlands at an altitude of 3,000–3,400 m (9,800–11,200 ft). Human settlement and large livestock population have forced the animal to occupy heath forests at an altitude of above 3,400 m (11,200 ft). Mountain nyala are endemic to the

International Union for Conservation of Nature and Natural Resources
(IUCN). Their influence on Ethiopian culture is notable, with the mountain nyala being featured on the obverse of Ethiopian ten cents coins.

Taxonomy

Phylogenetic relationships of the mountain nyala from combined analysis of all molecular data (Willows-Munro et.al. 2005)

The mountain nyala was first

described by English naturalist Richard Lydekker in 1910. Its scientific name is Tragelaphus buxtoni. The species has been classified under the genus Tragelaphus of the family Bovidae.[2] The mountain nyala was first brought to England in 1908 by Major Ivor Buxton, after whom the species has been named. Major Buxton, who had returned from a hunting trip in Ethiopia, first presented a specimen he had shot to British taxidermist Rowland Ward, who later on notified Lydekker about the discovery. It was the last large antelope to be discovered in Africa.[3][4] The spiral horns and white markings on the face and across the flanks established it as a species of Tragelaphus.[5] Lydekker believed that the species was related more closely to the nyala (T. angasii) than to the two kudu species (then placed under the genus Strepsiceros). In fact, mountain nyala's similarity to both Tragelaphus and Strepsiceros led to the merger of the latter into the former genus.[6][7]

In 2005, Sandi Willows-Munro of the

monophyletic clade with these three species.[8][9] The greater kudu clade split from the clade formed by mountain nyala, bongo, sitatunga and bushbuck approximately 8.6 million years ago.[10][11]

Description

The mountain nyala is a large

sexually dimorphic bovid. The head-and-body length is approximately 240–260 cm (94–102 in) in males and 190–200 cm (75–79 in) in females. The males are typically 120–135 cm (47–53 in) tall while females stand 90–100 cm (35–39 in) at the shoulder. Males weigh 180–300 kg (400–660 lb) and females weigh 150–200 kg (330–440 lb). The bushy tail reaches the heel, and is 20–25 cm (7.9–9.8 in) long.[12] The sensitive ears are large and lined with white hair.[5]

The coat is grey to brown, marked with two to five poorly defined white strips extending from the back to the underside, and a row of six to ten white spots. White markings are present on the face, throat and legs as well. The white

inguinal nipples.[12]

Only males possess horns, whose maximum recorded length is 188 cm (74 in). Horns appear as cream-coloured nubs at around six months and start growing in a spiral pattern, reaching full growth by two years.[5] The horns have only one or two spirals, though a few males have been reported to have two-and-a-half turns. The final form might vary in different males – the horns could form well-defined spirals, or could diverge in a structure similar to a lyre, resembling the horns of an impala, but with the final spiral incomplete. Growth rings are visible on the horn sheaths, but the annual patterns might be difficult to comprehend. Though the horns might wear out with age, the cream colour of the tips persists.[5][13]

The mountain nyala resembles the greater kudu in that both have an array of white spots along their flanks and possess spiral horns. However, the greater kudu can be told apart from the mountain nyala due to the former's greater height and paler colour. Moreover, the horns in greater kudu have two to three spirals, and the tips are farther apart. Another species similar to the mountain nyala is the nyala, but the latter can be easily distinguished from the former due to its smaller size and a fringe of long hair along its throat and neck. The horns of nyala, though very similar, are slender and narrower.[12]

Ecology and behaviour

A small herd

The mountain nyala are shy and elusive towards human beings. They spend the night on the edges of forests, feeding part of the time. To avoid human disturbance, they choose to navigate at night. They come out in morning and late afternoon to browse in grasslands. They generally seek cover in woodlands and heather thickets when it is very hot or cold. Feeding may occur in midday, but is interspersed with resting intervals. They tend to come out when it is overcast or raining. In the dry season (November to March), given the dilapidated state of grasslands, the mountain nyala travel up to the wooden areas rich in ericaceous heath.[14]

Four to five individuals may congregate for short intervals of time to form small herds. However, groups containing as many as 100 individuals have been reported from the

Dominance hierarchies are observed in both sexes.[15]

Males are not territorial, and have home ranges covering 15–20 km2 (5.8–7.7 sq mi) in the wet season. Females and juveniles, on the other hand, occupy much smaller ranges of about 5 km2 (1.9 sq mi) in the wet season. Dry season ranges are much larger than the wet season ones for both sexes.[16] Males often wrestle using their horns.[13] Though usually silent, the mountain nyala may "cough" noticing a potential threat, or utter a low bark if the threat is more serious.[3] The leopard is the main predator of the mountain nyala.[13]

Diet

Primarily a browser, the mountain nyala may switch to grazing occasionally. It feeds on low-height herbs, bushes, shrubs and general foliage. They might even eat

Hagenia abyssinica leaves. They prefer Alchemilla rotti, Helichrysum splendidum and lower foliage of Lobelia rhynchopetalum.[14][16]

Reproduction

Females start mating at two years of age, and males too become

sexually mature by that time. Sexual dimorphism, larger home ranges for males, and a female-biased population indicate polygyny in the species.[13] The mountain nyala breed throughout the year, but the peak occurs in December. Prior to and during the breeding season the adult males tend to get associated with mixed sex herds. Bulls continuously follow receptive females and test their vulvas. Three to four males may seek a single female, and, if equally ranked in hierarchy, may engage in circling displays. In these displays the males move very slowly and stiffly, with the crest on the back erect and the tail raised. They are less likely to engage in aggressive fights, which, if they happen, last only for a brief period. Flehmen follows vulva-testing.[3][12]

Gestation lasts for eight to nine months, after which a single calf is born. In the Bale Mountains National Park, births occur throughout the year, but peak from September to November. Calves remain in cover for the first few weeks after birth. The calves remain close to their mothers for nearly two years. The young females may get pregnant by then.[3] The young males, as they mature by two years, are challenged by other males and driven out of their herds.[5] The lifespan of a mountain nyala is around 15 to 20 years.[13]

Habitat and distribution

The range of mountain nyala is confined within Ethiopia.

The typical habitat for the mountain nyala is composed of

Hagenia abyssinica, juniper, and Hypericum revolutum in the upper reaches. They often visit the edges of montane grasslands at 2,800–3,100 m (9,200–10,200 ft), which is covered with Artemisia afra, Kniphofia, and evergreen Hypericum species.[12]

Nowadays the continuous blocks of woodland habitat have been reduced to a series of pockets, interspersed in large cultivated lands. Human settlement and large livestock population have forced the animal to occupy heath forests at an altitude of above 3,400 m (11,200 ft) rich in Erica arborea, Erica trimera, Hypericum, Euphorbia, and Helichrysum species. They may even be forced into afroalpine grasslands containing Alchemilla and Festuca species, at an altitude of up to 4,300 m (14,100 ft). In the eastern borders of its range, the mountain nyala has usually been observed to occupy areas at lower altitudes of about 1,800–2,400 m (5,900–7,900 ft).[12]

Mountain nyala are endemic to the

Shashamene and the northern Bale Zone to the south. Up to half of the total population of the mountain nyala occurs in the 200 km2 (77 sq mi) area of Gaysay, in the northern part of the Bale Mountains National Park. Smaller relict populations occur in Chercher, mountains such as Chilalo in Arsi Zone, and the western Bale.[17] A study identified an area of 39.38 km2 (15.20 sq mi) on the southern escarpment of the Bale Mountains as the most sustainable habitat for the mountain nyala.[18]

Threats and conservation

Taxidermied specimens at the American Museum of Natural History

Major threats to the survival of the mountain nyala include illegal hunting, habitat destruction, encroachment by livestock, predation of calves by dogs, expansion of montane cultivation and construction at high altitudes.[19][20] The animal is extensively hunted for its horns and meat. The meat is utilised in local medicine and for making nipples for traditional milk bottles. Impact of trophy hunting programs is obscure, and current trophy hunting quotas may be unsustainable in the long term although, if well regulated, trophy hunting could play an important role in the long term management of this species.[1][17]

The mountain nyala has been classified under the Endangered category of the

gully erosion, that the populations soon disappeared from there.[1][17]

In the 1960s, the population was estimated at 7,000 to 8,000 (and perhaps up to 12,500). This declined sharply to 2,000 to 4,000 individuals in the 1980s. The population is decreasing even now. The mountain nyala is feared to be extinct in the eastern and southern extremes of its range, though a few probably survive in

Kofele. Apart from Gaysay about 80 to 120 mountain nyala occur in the rest of the Bale Mountains National Park, and a few hundred occur in the areas in the vicinity of the national park.[1][17]

Relationship with humans

The influence of the mountain nyala, as well as the nyala, on Ethiopian culture can not be ignored. Although nyala is a South African word, several prominent businesses such as Nyala Motors use it in their names. The nyala and mountain nyala often regularly appear on walls, commercial products and tourist curios.[5] The mountain nyala is featured on the obverse of the Ethiopian ten cents coin.[5][24][25]

Mountain nyala are hunted by humans, for instance, by the Oromo people. The Oromo do not hunt these animals in general, except for a day close to Easter, when all able-bodied men set out on horses for a hunt.[5]

References

  1. ^ a b c d IUCN SSC Antelope Specialist Group (2017) [errata version of 2016 assessment]. "Tragelaphus buxtoni". IUCN Red List of Threatened Species. 2016: e.T22046A115164345.
  2. OCLC 62265494
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    S2CID 84219997
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  4. ISBN 978-1-78477-132-4
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  5. ^ a b c d e f g h i Malcolm, J.; Evangelista, P.H. (2005). "The range and status of the mountain nyala" (PDF): 1–43. Archived from the original (PDF) on 2016-01-28. {{cite journal}}: Cite journal requires |journal= (help)
  6. doi:10.1111/j.1096-3642.1911.tb01934.x
    .
  7. ^ Evangelista, P.; Waltermire, R.; Swartzinski, P. (2007). "A profile of the mountain nyala (Tragelaphus buxtoni)". African Indaba: 1–47.
  8. PMID 15878131
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  9. ISBN 978-1-4214-0093-8
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  10. ^ Ropiquet, A. (2006). "Etude des radiations adaptatives au sein des Antilopinae (Mammalia, Bovidae)". Ph.D. Thesis, Université Paris. 6 (1–247).
  11. PMID 22226162
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  12. ^
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  13. ^ a b c d e Aleman, M. "Tragelaphus buxtoni Mountain nyala". Animal Diversity Web. University of Michigan Museum of Zoology. Retrieved 21 January 2016.
  14. ^
    doi:10.1644/1545-1542(2000)081<0490:DPIEAB>2.0.CO;2
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  15. ^ Hillman, J.C.; Hillman, S.M. (1987). "The mountain nyala Tragelaphus buxtoni and the Simien fox Canis simensis in the Bale Mountains National Park". Walia. 10: 3–6.
  16. ^
    doi:10.1017/S0030605300026314
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  17. ^
    ISBN 978-2-8317-0477-7
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  18. doi:10.1071/WR07173
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  19. ^ Mamo, Y.; Bekele, A. (2011). "Human and livestock encroachments into the habitat of Mountain Nyala (Tragelaphus buxtoni) in the Bale Mountains National Park, Ethiopia". Tropical Ecology. 52 (3): 265–73.
  20. PMID 21943288
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  21. ^ Woldegebriel, G.K. (1996). "The status of mountain nyala (Tragelaphus buxtoni) in Bale Mountains National Park 1986–1994". Walia. 17: 27–37.
  22. doi:10.1093/czoolo/56.6.660
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  23. doi:10.1111/j.0141-6707.2004.00437.x
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  24. ISBN 978-1-4402-4410-0
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  25. ^ Balletto, B.L. (1995). Spectrum guide to Ethiopia. Camerapix Publishers. p. 295.

External links

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(Mountain nyala).
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