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Primate Discoveries in Northwest Kenya

In our last blog post (Discoveries From Two Years With Kenya’s Warthogs) we provided an overview of the major findings of our Quest for Kenya’s Desert Warthog. Of course, we collected a considerable amount of information on other species as well.

Here we present some of our findings about the primates of northwest Kenya.

Of the 25 genera and 93 species of primate in Africa, 12 genera, 19 species, and 25 subspecies occur in Kenya. Northwest Kenya is an under-explored region. As the primates of northwest Kenya have not been studied, we assessed which kinds are present, as well as their distributions, abundance, threats, and conservation status.

Moonrise over doum palms Hyphaene thebaica at one of the few oases in the Chalbi Desert, north Kenya. (Photograph by Yvonne de Jong and Tom Butynski)
Moonrise over doum palms (Hyphaene thebaica) at one of the few oases in the Chalbi Desert, north Kenya. (Photograph by Yvonne de Jong and Tom Butynski)


Mau Forest Guereza Ranging Wider and Higher

A population of Mau Forest guereza (Colobus guereza matschiei) was found in the central Cherangani Hills. This extends the geographical range of this subspecies 50 km to the northeast (from Mt. Elgon). It is likely that the range of Mau Forest guereza extents to the north end of the Cherangani Hills. Previously, the highest altitude reported for this subspecies was 2,900 m above sea level. Two groups of Mau Forest guereza were, however, encountered at 3,009 m above sea level. We found that most of the natural forest of the Cherangani Hills had been cleared, and that much of what remained was degraded and fragmented.

Subadult Mau Forest guereza (Colobus guereza matschiei). (Photograph by Yvonne de Jong and Tom Butynski)
Subadult Mau Forest guereza (Colobus guereza matschiei). (Photograph by Yvonne de Jong and Tom Butynski)
Adult male Mau Forest guereza (Colobus guereza matschiei) at 3,009 m above sea level in the Cherangani Hills, central west Kenya. Photograph by Yvonne de Jong and Tom Butynski.
Adult male Mau Forest guereza (Colobus guereza matschiei) at 3,009 m above sea level in the Cherangani Hills, central west Kenya. (Photograph by Yvonne de Jong and Tom Butynski)

Wider Range for the Eastern Patas Monkey 

A group of eastern patas monkeys (Erythrocebus patas pyrrhonotus) was encountered in the south end of the Karasuk Hills, close to the Uganda border, central west Kenya. Interviews with local people indicate the presence of many groups of eastern patas monkeys in this region. This locality record confirms earlier reports of eastern patas monkeys along the Kenya-Uganda border and falls within a distribution gap of about 130 km (between western Turkana County and western West Pokot County). The current range of the eastern patas monkey in Kenya is estimated at 52,520 km² (in 2008 we estimated this to be 48,200 km²). This is about 56 percent of the historic range.

Two adult female eastern patas monkeys (Erythrocebus patas pyrrhonotus) on the southern end of the Karasuk Hills of North Pokot, northwestern Kenya, a few kilometers from the Uganda border. This represents the first patas monkey record for the Karasuk Hills and connects the Turkana and Pokot patas populations along the Kenya-Uganda border. Photograph by Yvonne de Jong and Tom Butynski.
Two adult female eastern patas monkeys (Erythrocebus patas pyrrhonotus) on the southern end of the Karasuk Hills of North Pokot, northwestern Kenya, a few kilometers from the Uganda border. This represents the first patas monkey record for the Karasuk Hills and connects the Turkana and Pokot patas populations along the Kenya-Uganda border. (Photograph by Yvonne de Jong and Tom Butynski)
Adult female eastern patas monkey (Erythrocebus patas pyrrhonotus). Photograph by Yvonne de Jong and Tom Butynski.
Adult female eastern patas monkey (Erythrocebus patas pyrrhonotus). (Photograph by Yvonne de Jong and Tom Butynski)

A Rainbow of Savanna Monkeys 

Instead of noticing separate ranges, we observed a gradation of physical traits from one species to another of savanna monkeys (Chlorocebus spp.) across central west and northwest Kenya. Individuals in a group of supposed vervet monkeys (Chlorocebus ‘pygerythrus’) at Lodwar had some of the coat color characters of the grivet monkey (Chlorocebus aethiops). The known range of the grivet monkey includes southeast South Sudan … but not Kenya or Uganda. The one adult male savanna monkey observed at Karasuk Hills showed color characters of the tantalus monkey (Chlorocebus tantalus).

Adult male ‘vervet’ monkey (Chlorocebus ‘pygerythrus’) at Lodwar, Turkana, northwest Kenya. Photograph by Yvonne de Jong and Tom Butynski.
Adult male ‘vervet’ monkey (Chlorocebus ‘pygerythrus’) at Lodwar, Turkana, northwest Kenya. (Photograph by Yvonne de Jong and Tom Butynski)
Adult male
Adult male “vervet monkey” (Chlorocebus ‘pygerythrus’) in the Karasuk Hills, central west Kenya near the Uganda border. This individual had white tufts of hair on either side of the base of the tail and a white, medium-broad, sinuous brow-band. These are traits of tantalus monkey (Chlorocebus tantalus). (Photograph by Yvonne de Jong and Tom Butynski)

Altitude and Rainfall Records for the Olive Baboon

During this survey we encountered 80 groups of olive baboons (Papio anubis). These groups were at altitudes ranging from 369 m asl (Kalacha, an oasis town in the northern Chalbi Desert) to 2,320 m asl (Lolldaiga Hills, Laikipia County). Previously, the lowest altitude record for olive baboons in East Africa was at 540 m above sea level (Meru National Park, central Kenya).

Group of olive baboons (Papio anubis) south of Sibiloi National Park, east of Lake Turkana, northwest Kenya. Mean annual rainfall here is ca. 200 mm..Photograph by Yvonne de Jong and Tom Butynski.
Group of olive baboons (Papio anubis) south of Sibiloi National Park, east of Lake Turkana, northwest Kenya. Mean annual rainfall here is about 200 mm. (Photograph by Yvonne de Jong and Tom Butynski)

Olive baboons typically drink daily. In north Kenya, olive baboons occupy areas with a mean annual rainfall as low as about 200 mm (Marsabit County, east of Lake Turkana). This is a lower rainfall than previously reported for this species (300 mm, west Eritrea). The absence of drinking water for several months at a time in these areas indicates that olive baboons are able to survive without drinking for extended periods. This has not been previously reported (see our blog: Secret to Olive Baboon Survival in a Barren Desert).

Two New Populations of the Somali Lesser Galago

Two new populations of Somali lesser galago (Galago gallarum) were located; one in an oasis on the eastern edge of the Chalbi Desert (New Population of Bushbabies Discovered in Northern Kenya) and one on the southern foothills of Mt. Forole, central north Kenya. These sites extend the known geographical range for the Somali lesser galago in north Kenya about 100 km west into the Chalbi Desert and about 80 km west along the Kenya-Ethiopia border, respectively.

Somali lesser galago (Galago gallarum) in an oasis in the Chalbi Desert, north central Kenya. Photograph by Yvonne de Jong and Tom Butynski
Somali lesser galago (Galago gallarum) in an oasis in the Chalbi Desert, north central Kenya. (Photograph by Yvonne de Jong and Tom Butynski)
Geographical range of the Somali lesser galago (Galago gallarum) in Kenya (indicated in orange). The two newly discovered populations are indicated by red circles.
Geographical range of the Somali lesser galago (Galago gallarum) in Kenya (indicated in orange). The two newly discovered populations are indicated by red circles.

Two New Localities for Senegal Lesser Galago

Two new localities for the Senegal lesser galago (Galago senegalensis senegalensis) were found; one in the Charangani Hills and one in Saiwa Swamp National Park, central west Kenya.

Senegal lesser galago (Galago senegalensis senegalensis) at Saiwa Swamp National Park, Trans Nzoia County, central west Kenya. Photograph by Yvonne de Jong and Tom Butynski.
Adult Senegal lesser galago (Galago senegalensis senegalensis) at Saiwa Swamp National Park, Trans Nzoia County, central west Kenya. (Photograph by Yvonne de Jong and Tom Butynski)
Geographical range of the four subspecies of northern lesser galago (Galago senegalensis) over the northern half of Kenya. The two sites for G. s. senegalensis located during this project are depicted by red circles, and a reported third locality is depicted by a black circle.
Geographical range of the four subspecies of northern lesser galago (Galago senegalensis) over the northern half of Kenya. The two sites for the northern lesser galago located during this project are depicted by red circles, and a reported third locality is depicted by a black circle.

Additional photographs obtained during this project can be viewed at: www.wildsolutions.nl. These include photographs of primates, warthogs, hyraxes, antelopes and landscapes.

To obtain the final report for this project, go to www.wildsolutions.nl.

Sunset over the open wooded savannah of Turkana, northwestern Kenya. Photograph by Yvonne de Jong and Tom Butynski.
Sunset over the open wooded savannah of Turkana, northwestern Kenya. Photograph by Yvonne de Jong and Tom Butynski.

Comments

  1. Janine
    France
    January 19, 2015, 8:55 am

    What a fantastic find ! I truly hope nothing changes for these primates, certainly not by man’s hand !