New publication Primate Conservation 39: 97–109 (2025)
Does the Spectacled Lesser Galago Galago matschiei Lorenz, 1917 (Primates: Strepsirrhini: Galagidae) Occur East of Uganda’s Lake Victoria-Nile River Basin?
Thomas M. Butynski and Yvonne A. de Jong
Abstract: Although primates are one of the best studied taxonomic groups of African mammals, the geographic limits for most taxa remain poorly known. This is particularly true for the Galagidae. We explore whether the spectacled lesser galago Galago matschiei occurs east of Uganda’s Lake Victoria-Nile River Basin. Furthermore, we list those primates for which this basin and Kenya’s Eastern (Gregory) Rift Valley are geographic barriers. Mount Moroto lies east of the Lake Victoria-Nile River Basin. Nash et al. (1989, Int. J. Primatol. 10: 57–80) stated that G. matschiei occurs on Mount Moroto, central eastern Uganda. They do not, however, provide information in support of this statement. We suspect that they misidentified specimens collected in 1952 on Mount Moroto. Of the 12 specimens collected, four are adults housed in the British Museum of Natural History in London. We compared these four adult specimens with two adult G. matschiei specimens from the Democratic Republic of the Congo and confirm that all four are northern lesser galagos Galago senegalensis. Field surveys and a review of the literature and online repositories yield no evidence for G. matschiei on Mount Moroto, or anywhere else east of the Lake Victoria-Nile River Basin. The only Galago collected or reported for this vast region is G. senegalensis. At this time, Uganda’s Lake Victoria-Nile River Basin appears to be the eastern geographic barrier for four primate species, while Kenya’s Eastern Rift Valley seems to be an eastern geographic barrier for six primate species.
Since 2009 we had the privilege to visit Mahale National Park three times. Click here to access our Mahale publications, sound recordings, camera trap videos, and photographs from these visits, as well as the description of a new primate for Mahale, the Mahale Angola Colobus.
Primates of Mahale Mountains National Park, Tanzania
New publication Journal of East African Natural History 114(10): 94–105 (2025)
A new large primate for Kenya: Hamadryas baboon Papio hamadryas (Primates: Cercopithecidae)
Yvonne A. de Jong and Thomas M. Butynski
Abstract: The hamadryas baboon Papio hamadryas is a large, terrestrial primate endemic to the Arabian Peninsula and Northeast Africa. There are no records of this primate in Kenya. From February 2023 through April 2025, we conducted eight surveys across northern Kenya, from the eastern shore of Lake Turkana eastward to Malka Mari National Park and Wajir. We encountered 37 groups of baboons Papio between Marsabit and Malka Mari National Park, 32 of which were olive baboons Papio anubis. These encounters extend the known geographic distribution of this monkey in northeastern Kenya ~50 km to the east. At least four groups of P. hamadryas were observed in Malka Mari National Park between 655 m asl and 680 m asl. These records are ~75 km southeast of the known range of P. hamadryas in southern Ethiopia, ~100 km northeast of the easternmost P. anubis group, and ~125 km west of the documented range of northern yellow baboon Papio cynocephalus ibeanus. These are the first records of P. hamadryas for Kenya and, thus, for East Africa. We speculate that the range of P. hamadryas extends from Malka Mari National Park northward into Ethiopia along the Daua River, eastward along the Daua River on the Kenya-Ethiopia border to Ramu, and westward to Lulis, just beyond the southwestern corner of Malka Mari National Park. With this addition, Kenya’s primate community comprises three Papio species and four Papio taxa, and a total non-human primate community of 11 genera, 19 species, and 34 taxa.
Distribution, Abundance, and Conservation Status of the Aïr Patas Monkey Erythrocebus patas villiersi Dekeyser, 1950 (Primates: Cercopithecidae) in the Aïr Massif-Gadabedji Region, Niger
Yvonne A. de Jong, Adouma Alghoubas, Abdoul Razack Moussa Zabeirou, Mahamane Hassane and Thomas M. Butynski
Abstract: The Aïr patas monkey Erythrocebus patas villiersi is regarded as isolated and endemic to the Aïr Massif of central north Niger, West Africa. The limits of the geographic range of E. p. villiersi are poorly understood, there is no detailed description of the coloration and pattern of its pelage, and its abundance, ecology, behavior, and threats remain unstudied. As a result, this subspecies is listed as ‘Data Deficient’ on TheIUCN Red List of Threatened Species. Based on field observations and photographs, we describe the phenotype of the adult male E. p. villiersi. Spatial data were collected from the literature, museums, colleagues, naturalists, local experts, and online resources to assess its geographic range. The geographic range was overlaid with ArcGIS datasets for altitude, rainfall, temperature, and ecoregions.
