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Mountain nyala; Gedemsa

Tragelaphus buxtoni (Lydekker, 1910)
French: Le Nyale des montagnes
German: Bergnyala
Spanish: Niala de montaña
Lokal name/s: Azagen

Endemic subspecies
There are no endemic subspecies.

Description
Total length: (f) 190 - 200 cm, (m) 240 - 260 cm
Tail length: 20 - 25 cm
Shoulder height: (f) 90 - 100 cm, (m) 120 - 135 cm
Weight: (f) 150 - 200 kg, (m) 180 - 300 kg
Horns: (f) hornless, (m) up to 110 cm
Gestation: ~ 6 months

The Mountain nyala (Gedemsa) is a large antelope with a shaggy greyish-brown coat and four poorly defined vertical white stripes on each side. There are two white patches on the throat and two white spots on each cheek. Only males carry the open spiralled horns. The males are larger than the females, but otherwise both sexes are similar in coloration and overall appearance. In many ways they look more like the Kudu than like the Nyala (Tragelaphus angasi) of Southern Africa.

Distribution
This species is now limited to the Bale massif, the highland area of east-central Ethiopia. It ranges from 3.000 to 4.200 m but stragglers occur as low as 1.800 m.

Ecology
Currently flourishes best in a mosaic of high-altitude woodland, bush, heath, moorland and valley-bottom grassland. It isn't venturing into the open, but prefers highland forest and thickets. The woodlands, heath and bush provide dryseason refuge and are main basis of their browse. With the rains there is a greater choice of pasture at lower levels (a similar pattern found with the bongo in mountains). The sedgy grasslands tend to be waterlogged and animals have even been seen eating water-plants. The mountain nyala lives in small herd of up to 14 individuals. Older males can often be found solitary. It is adapted to the freezing temperatures which may occur at night. The voice is a deep grunt.

Conservation Status
Due to its very localised range this species is very vulnerable to ecological and political upheavals. A total number 2.000 to 4.000 animals was estimated in 1988, although at least half of this population was restricted to a small part of Bale Mountains NP. Numbers have significantly decreased. The effects of trophy hunting may not be well understood.

IUCN Red List Category, ver 3.1:

- http://www.iucnredlist.org/details/22046/0

Trend:

European Collection Plan: ...

RCP status: under review

Recommendations
The establishment of protected satellite populations in the Arssi and Hrerghe Mtns, and an ex situ breeding program may mitigate the vulnerability of the Bale nucleus poplation. The Bale Mountains N.P.  should be protected from overgrazing by domestic animals. Protecting the park from any illegal  activity by regular patrolling inside the park is crucial.

Literature
Dorst J & Dandelot P (1970): Larger Mammals of Africa, Collins Field Guide, London.
Duckworth F (2001): Ethiopia - an Assessment of the Wildlife Situation - November 200. Gnusletter, 21(1): 14-17.
East R (1999): African Antelope Database 1998. IUCN/SSC Antelope Specialist Group. IUCN, Gland, Switzerland and Cambridge, UK.
Evangelista PH (2006): Der Bergnyala - ein bedrohter Endemit aus den äthiopischen Bergen. ZGAP Mitteilungen, 2: 23-24.
Evangelista PH, Swartzinski P & Waltermire R (2007): A profile of the mountain nyala (Tragelaphus buxtoni). Reprt, 47 pp.
Haltenorth T & Diller H (1997): Saeugetiere Afrikas und Madagaskars, BLV Verlagsgesellschaft, Muenchen.
Kingdon J (1997): The Kingdon Field Guide To African Mammals, Academic Press, San Diego.
Malcolm J (2003): Mountain Nyala Survey. Gnusletter, 22(1): 8-10.
Malcolm J & Evangelista PH (2005): The Range and Status of the Mountain Nyala. Report, 42 pp.
Refera B & Bekele A (2004): Population status and structure of mountain nyala in the Bale Mountains National Park, Ethiopia. African Journal of Ecology, 42: 1-7.
Schloeder C et al. (1997): Ethiopia. IUCN-ASG Antelope Survey Update, Sep 1997, 6:23-49.
Wison DE & Reeder DM (2005): Mammal species of the world. A taxonomic and geographic reference. Third Ed., Vol. 1. The John Hopkins University Press, Baltimore.

 

Links

- http://www.ultimateungulate.com/Artiodactyla/Tragelaphus_buxtoni.html
- http://www.arkive.org/mountain-nyala/tragelaphus-buxtoni/
- http://www.gisbau.uniroma1.it/amd/amd220b.html

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