Wildsolutions
  • Home
  • News
  • Biogeography, Taxonomy, Abundance, and Conservation Status of the Primates of Northeast Uganda and West Kenya

Biogeography, Taxonomy, Abundance, and Conservation Status of the Primates of Northeast Uganda and West Kenya

Report for the National Geographic Society
Thomas M. Butynski & Yvonne A. de Jong
Eastern Africa Primate Diversity and Conservation Program & Lolldaiga Hills Research Programme

EXECUTIVE SUMMARY

At the country-level, the biogeography, taxonomy, abundance, and conservation status of most of East Africa’s non-human primates remains poorly-known. During this survey, ‘rapid surveys’ were used to gather data on the biogeography, taxonomy, abundance, and conservation status of the primates of northeast Uganda.

A total of 402 h of survey were conducted (261 h diurnal and 141 h nocturnal, including 125 h listening) during two field trips in west Kenya and northeast Uganda. The two principal researchers each spent 30 days in the field. A total of 5,787 km were surveyed (5,690 km diurnal, 97 km nocturnal).

 

Survey vehicle on Mnt Elgon, west Kenya. Photograph by Yvonne de Jong.

Natural history and conservation data were obtained for seven genera, eight species, and 11 subspecies of primate. In addition, indirect evidence for eastern robust chimpanzee Pan troglodytes schweinfurthii was collected in the Otzi Mts., north Uganda.

Diurnal primates were encountered at 0.01 groups/km and 0.27 groups/h (n=62 groups) during vehicle surveys and 0.21 groups/km and 0.42 groups/h (n=12) during foot surveys. These groups represented five genera, six species, and nine subspecies; western guereza Colobus guereza occidentalis (n=2 groups), Mau Forest guereza Colobus guereza matschiei (n=17), Mt. Kenya guereza Colobus guereza kikuyuensis (n=3), Dodinga Hills guereza Colobus guereza dodingae (n=3), olive baboon Papio anubis (n=30), eastern patas monkey Erythrocebus patas pyrrhonotus (n=6), Budgett’s tantalus monkey Chlorocebus tantalus budgetti (n=5), Hilgert’s vervet monkey Chlorocebus pygerythrus hilgerti (n=7), savanna monkey Chlorocebus sp. (n=3), Stuhlmann’s blue monkey Cercopithecus mitis stuhlmanni (n=23), and Kolb’s monkey Cercopithecus mitis kolbi (n=2).

Nocturnal primates were encountered at 0.14 individuals/km and 1.20 individuals/h (n=12 individuals) during vehicle surveys and 0.38 individuals/km and 0.50 individuals/h (n=3) during foot surveys. Two genera, two species, and two subspecies were encountered; eastern potto Perodicticus potto ibeanus (n=2) and Senegal lesser galago Galago senegalensis senegalensis (n=24).

Imatong Mountains of Uganda. Photograph by Yvonne de Jong & Tom Butynski.

Colobus g. dodingae, was found in Agoro-Agu Forest Reserve (FR), central north Uganda. This finding is important as it (1) reduces the list of endemic primate subspecies in South Sudan by one; (2) is an additional primate subspecies for Uganda and East Africa; and (3) establishes C. g. dodingae as one of the most threatened primate subspecies in Uganda and East Africa.

Dodinga Hills guereza Colobus guereza dodingae skin, Imatong Mountains of Uganda. Photograph by Tom Butynski.

Two groups of C. g. occidentalis were encountered in Otzi East Central Forest Reserve (CFR). This is the first record of this species for this forest. The Otzi Mts. represent the northeast limit for C. g. occidentalis. The White Nile River is the geographic barrier that separates C. g. occidentalis in the west from C. g. dodingae in the east.

Pan t. schweinfurthii, discovered in Otzi East CFR in 1993, was not encountered, and only indirect evidence of its (past) presence found. Residents claimed that P. troglodytes sometimes occupy Mt. Nyeri (Otzi East CFR) but seasonally move up Mt. Nyeri and into South Sudan’s Nimule National Park (NP). None of the residents interviewed had seen or heard chimpanzees within the last 3 years.

A group of P. anubis was observed at 2,738 m above sea level (asl) on Mount Elgon NP, west Kenya. The previous altitude record for P. anubis in East Africa is 2,550 m asl.

Adult male olive baboon Papio anubis lounging at the at Mount Elgon National Park at 2,150 m asl, western Kenya. Photograph by Yvonne de Jong & Tom Butynski.

Six groups of E. p. pyrrhonotus were encountered during this survey, all in Kidepo Valley NP. Reports were obtained of presence in seven other areas.

Four groups and one individual C. t. budgetti were encountered. Four groups and three solitary individuals C. p. hilgerti were encountered. All individuals encountered (solitary or within a group) were shy.

An adult male Budgett’s tantalus monkey Chlorocebus tantalus budgetti calls out at Umi, south of the Otzi Mountains and east of the White Nile, north Uganda. Photograph by Yvonne de Jong & Tom Butynski.

Cercopithecus m. stuhlmanni was encountered in and near Agoro-Agu FR. Residents said this monkey is present within and near Kidepo Valley NP. These localities are near the north limit for C. m. stuhlmanni. Cercopithecus mitis on Mt. Elgon is considered by some authorities to be C. m. elgonis. Based on preliminary phenotypic analysis we suspect that elgonis is not a valid subspecies, and that C. m. elgonis is best placed as a synonym of C. m. stuhlmanni.

Perodicticus i. ibeanus was encountered twice in Teressa Forest Reserve (FR), southwest Kenya. This is a new locality record for this species but well within the known geographic range.

Galago s. senegalensis was found at three sites in north Uganda (Kidepo Valley NP, Agoro-Agu FR, and Otzi East CFR), and at one site in southwest Kenya (Teressa FR). All four localities are new for this subspecies but well within the known geographic range.

Northern lesser galago Galago senegalensis near Agoro-Agu Forest Reserve, Imatong Mountains, central-north Uganda. Photograph by Yvonne de Jong & Tom Butynski.

Fifteen genera, 24 species, and 18 subspecies of primate occur in Uganda. Six species (25%) and seven subspecies (39%) were assessed as ‘Threatened’ during the IUCN/SSC African Primate Red List Assessment Workshop in Rome (April 2016). Of these, two species are ‘Critically Endangered’; robust chimpanzee Pan troglodytes and eastern gorilla Gorilla beringei.

The future for most primate taxa in northeast Uganda appears bleak. Overall, primate densities are low, populations are small and fragmented, and the individuals of all taxa are shy and wary of humans. Primates are hunted over all of northeast Uganda and people are generally intolerant of primates outside protected areas.

Imatong Mountains of Uganda. Photograph by Yvonne de Jong & Tom Butynski.

The pressure on the few remaining forests of northeast Uganda is very high due to a growing scarcity of natural resources in the face of a human population that is doubling every 20–25 years. Frequent bush fires, logging, collection of poles and firewood, charcoal production, and agricultural encroachment into protected areas, are all contributing to the degradation, loss, and fragmentation of the natural habitats of this region, particularly the woodlands and forests. In addition, primates are hunted for meat and in response to crop raiding. These threats are of particular concern for forest-dependent species.

Read the full report here

 

Trackback from your site.

Leave a comment