Quest for Kenya´s Desert Warthog

Yvonne de Jong is a National Geographic grantee working to track down what may be Africa’s least understood large animal, the Desert Warthog.


There are two species of warthog, the common warthog (scientific name Phacochoerus africanus) and the desert warthog (Phacochoerus aethiopicus). The better known of the two, the common warthog (indeed… ‘Pumba’ in the ‘Lion King’), is widespread in sub-saharan Africa, including the Horn of Africa (i.e., Kenya, Somalia, Ethiopia, Djibouti, Eritrea). The desert warthog, on-the-other-hand, is restricted to the Horn of Africa. Until recently, observers in the Horn of Africa have not differentiated between the two species of warthog. As such, the limits of the distributions of these two species over the Horn of Africa remains poorly known, as does their conservation status.

As of 2001, all records for the desert warthog were north of the Tana River in extreme eastern Kenya. On this basis, zoologist suspected that the Tana River (a large, 1000 km long river that runs from central Kenya south-eastward to the Indian Ocean) was the southern limit of the desert warthog. In 2005, however, we encountered this species close to, but south of the Tana River during one of our primate surveys. These observations also extended the known geographical range of the desert warthog by almost 270 km to the northwest.

Adult male desert warthog in Tsavo West National Park, south-eastern Kenya. Note the flipped-back ear tips, hooked warts, broad, ‘egg-shaped’, head, swollen suborbital area, and relatively wide nose pad. Photograph by Tom Butynski & Yvonne de Jong.


Common warthog
Adult male common warthog on the Laikipia Plateau, central Kenya. Note the pointed ears, cone-shaped warts, ‘diabolo-shaped’ head, absenceof swelling of the suborbital area, and relatively narrow nose pad. Photograph by Tom Butynski & Yvonne de Jong


Our encounters with desert warthogs in 2005 marked the beginning of our quest to better determine the geographic range of this species and to collect the information needed for assessing its conservation status. With the desert warthog now known to occur south of the Tana River, we were particularly interested in determining the species’ southern limit. A second important question at the time was whether the desert warthog occur together with the common warthog at some sites.

Now, in 2012, we know that both species of warthog occur together (i.e., they are ‘sympatric’) in Tsavo East National Park and Tsavo West National Park in south-eastern Kenya, and in Samburu National Reserve, Buffalo Springs National Reserve, and Mathews Range in central Kenya. The known southern limit has been extended to the western extreme of Tsavo West National Park. With a warthog locality database (named ‘WarthogBase’) in place, we have now mapped all of the known localities for the two species of warthog in the Horn of Africa. This, however, only begins to provide insight into the distributions of these two warthogs in this region as extremely large areas remain to be surveyed.

The desert warthog is probably Africa’s least known, non-forest, large mammal as its distribution is poorly understood and it has never been the focus of an ecological or behavioural study. This year, with financial support from National Geographic, we are undertaking warthog surveys in northern Kenya. The primary question that we hope to answer is, ‘What are the western and south-western limits of the range of the desert warthog in northern Kenya?’ During these surveys we will also collect data on the abundance, ecology and behavior of both species of warthog.

In this series of blogs we will present some of our findings. While exploring this relatively poorly known part of Kenya for warthogs we will also collect data on, and take photos of, the region’s primates, large mammals and birds, particularly the more threatened species (e.g., Grevy’s zebra Equus grevyi). Our future blogs will highlight some of our more important and interesting findings.

For more information on warthogs and our other research, past and present, please visit  This site holds many photos, distribution maps, and pdfs of publications and reports.

Learn More

National Geographic Warthog Info Page

Guide to Kenya



Meet the Author
Yvonne A. de Jong (PhD) is a Kenya-based Dutch primatologist who has worked in Africa for more than 13 years. She is member of the Nocturnal Primate Research Group at Oxford Brookes University, member of various IUCN/SSC Specialist Groups including the Primate and Wild Pig Specialist Groups, and Collaborating Scientist of the Institute of Primate Research in Nairobi. Her main research focus is the biogeography, diversity and conservation of eastern Africa's primates and several other groups of large mammals, including the warthogs. She is the co-leader of the Eastern Africa Primate Diversity and Conservation Program and senior ecologist at the Lolldaiga Hills Research Programme )Sustainability Centre Eastern Africa' based in Laikipia, Kenya. Thomas M. Butynski (PhD) is an American conservationist and ecologist who has worked in Africa for 45 years, mostly in Botswana, Kenya, Uganda, and Equatorial Guinea. He is a member of four IUCN/SSC Specialist Groups (Primates, Antelopes, Afrotheria, Wild Pigs) and has served as Director of the Institute of Tropical Forest Conservation in Uganda, Director of Conservation International’s Eastern Africa Biodiversity Hotspots Program in Kenya, Director of the King Khalid Wildlife Research Center in Saudi Arabia, Vice-Chair of the Africa Section of the IUCN/SSC Primate Specialist Group, Senior Editor of the journal African Primates, and a Senior Editor for Mammals of Africa. At present he is Co-leader of the Eastern Africa Primate Diversity and Conservation Program, and Director of Research at the Sustainability Centre Eastern Africa in Kenya.