Investigating the Biogeographic Niche of Baboon Species in Southern Kenya Using GIS

Abstract

Studies on primate distribution and diversity continue to make important contributions to scientific knowledge on species ecology and evolution, and baboons (genus Papio) are an ideal model species for biogeographic studies. Whereas the distribution of baboons across Africa has been documented, there isn’t enough information on the biogeographic niche of baboon species at the subcontinental scale. Here, Geographic Information Systems were used to investigate the biogeographic niche of anubis baboons, yellow baboons, and their hybrids in southern Kenya. First, a field survey was conducted to ascertain the distribution of baboons in the study area. Next, baboon populations encountered during the field survey were categorized according to their ancestry, i.e. either unadmixed anubis baboon, hybrid, or unadmixed yellow baboon populations. Biogeographic variables representing geography (altitude and distance from the ocean), vegetation, and climate were then estimated for sites where baboons were encountered. Next, using Geographically Weighted Regression Analysis (GWRA) between-species biogeographic niche was assessed, and finally, using Environmental Niche Factorial Analysis (ENFA), within-species biogeographic niche was assessed. The study established that baboon species in southern Kenya (Kanjiado, Makueni and Taita Taveta) were in allopatry, with anubis baboons were found in the north-west, yellow baboons found in the south-east, and hybrids found in between. Between-species niche analysis using GWRA established that there was no significant difference in biogeography between anubis baboons, yellow baboons, and their hybrids whereas within-species niche analysis using ENFA established that each baboon species was highly tolerant to different biogeographic conditions. The results of this study support the designation of anubis and yellow baboons as highly adaptive generalists that are able to survive in different biogeographic conditions.