Tragelaphus eurycerus ssp. isaaci 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Mammalia Cetartiodactyla Bovidae

Scientific Name: Tragelaphus eurycerus ssp. isaaci (Thomas, 1902)
Parent Species:
Common Name(s):
English Mountain Bongo, Eastern Bongo
Taxonomic Notes: Mountain Bongo is treated here as a separate subspecies. Genetic research into its taxonomic status is ongoing.

Assessment Information [top]

Red List Category & Criteria: Critically Endangered C2a(i) ver 3.1
Year Published: 2017
Date Assessed: 2016-09-06
Assessor(s): IUCN SSC Antelope Specialist Group
Reviewer(s): Cooke, R.
Numbers of this isolated subspecies have undergone a severe decline. Very small remnant populations survive in the Aberdares (<50), Mount Kenya (10-15), Eburu Forest (ca 10), Maasai Mau Forest Complex (20+; new Bongo groups discovered May 2013) and SW Mau Forest (<10). Current estimates (Mountain Bongo Surveillance Project 2015) therefore suggest a total of ca 100 individuals, well below the Critically Endangered threshold of 250 mature individuals. The taxon is still declining and none of the subpopulations listed above contains 50 mature individuals.
Previously published Red List assessments:

Geographic Range [top]

Range Description:Eastern or Mountain Bongo formerly occurred in and around forested mountains zones of Mt. Kenya, the Aberdares, Mau forest, Cherengani hills and Chepalungu hills in Kenya and Mount Elgon in Kenya and Uganda (Elkan and Smith 2013). Mountain Bongo was exterminated from the Uganda side of Mount Elgon around 1913-1914 (Kingdon 1982) and it is now confined to four completely isolated populations in patches of forest on Mt. Kenya, Mau Forest, Eburu Forest and the Aberdares in Kenya (Elkan and Smith 2013, Mountain Bongo Surveillance Project 2015).

For the distribution map, see the species-level assessment: Tragelaphus eurycerus.
Countries occurrence:
Regionally extinct:
Additional data:
Number of Locations:4
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:The current population estimate (Mountain Bongo Surveillance Project 2015) for the Mountain Bongo is ca 100 individuals: Aberdare Mts (<50); Mt Kenya (10-15); Eburu Forest (ca 10); Maasai Mau Forest Complex (20+; new Bongo groups discovered May 2013); and SW Mau Forest (<10).
Current Population Trend:Decreasing
Additional data:
Number of mature individuals:70-80Continuing decline of mature individuals:Yes
Extreme fluctuations:NoPopulation severely fragmented:Yes
No. of subpopulations:5
All individuals in one subpopulation:No

Habitat and Ecology [top]

Habitat and Ecology:The Mountain Bongo is associated with  montane forests in the Kenya highlands. Bongo thrive on transition vegetation at the forest edge and in new growth areas that occur after disturbance (post-timber exploitation, elephant disturbance, tree-falls, landslides, burned fields; Elkan and Smith 2013). Forest clearings and mineral licks are important for geophagy and socialization (Elkan and Smith 2013, and references therein). Bongo are primarily browsers, but exhibit some seasonal grazing on grasses (Elkan and Smith 2013). There is a record from 4,300 m on Mount Kenya (Young and Evans 1993).
Generation Length (years):8.0

Use and Trade [top]

Use and Trade: There has been an increase in hunting of Mountain Bongo by local people, including hunting with dogs.

Threats [top]

Major Threat(s): Threats to Mountain Bongo include hunting with dogs and loss of habitat in the Mau and Eburu forests to illegal logging. The decline of Mountain Bongo populations in the Aberdares in recent years has been attributed to increased hunting by local people and habitat loss, and even to the increased numbers of Lion in the area (Elkan and Smith 2013). Although these factors have no doubt contributed to the decline of Mountain Bongo, the impact of disease has probably been underestimated: the grazing of cattle in the forest reserves of Mount Kenya and the Aberdares as high as the Hagenia forest on the Aberdares plateau may have greater implications for Bongo conservation than hunting pressure in terms of disease transmission (L. Estes pers. comm. in Elkan and Smith 2013). Percival (1928) reported that rinderpest drastically reduced the populations of Mountain Bongo in the 1890s, and populations are thought to have suffered greatly in later epidemics in the early 1900s.

Conservation Actions [top]

Conservation Actions: The Mountain Bongo’s survival in the wild is dependent on more effective protection of the surviving remnant populations in Kenya (East 1999). Two conservation initiatives are currently in progress on Mountain Bongo. A program to reintroduce Bongo to Mt Kenya began in 2004, when 18 animals where flown from North American zoos to a captive-breeding facility at Mount Kenya Game Ranch, on the north-western slope of the mountain. A second phase began in 2005, with the commencement of a research program into the Mountain Bongo’s ecology. This project will attempt to determine the configuration of Bongo habitat on both the Aberdares and Mount Kenya, using recently collected field and remotely sensed data (L. Estes pers. comm. in Elkan and Smith 2013). Meanwhile, the Bongo Surveillance Program, initiated in 2004, has been investigating the status of the remaining wild Bongo populations in Kenya (L. Estes pers. comm. in Elkan and Smith 2013).

Citation: IUCN SSC Antelope Specialist Group. 2017. Tragelaphus eurycerus ssp. isaaci. The IUCN Red List of Threatened Species 2017: e.T22057A50197212. . Downloaded on 21 September 2018.
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