Endangered species in small habitat patches can possess high genetic diversity: the case of the Tana River red colobus and mangabey

• Published in: Conservation genetics 2010-10, Vol.11 (5), p.1725-1735
• Main Authors: Mbora, David N. M, McPeek, Mark A
• Format: Article
• Language: English
• Subjects: Animal Genetics and Genomics; Biodiversity; climate change; Conservation; Conservation biology; Conservation Biology/Ecology; Dispersal; Ecology; Endangered & extinct species; Endangered animals; Endangered species; Evolutionary Biology; Forests; Genetic diversity; Genetic drift; Genetic structure; genetic variation; Habitat changes; Habitat fragmentation; Habitat loss; Habitats; Life Sciences; mitochondrial DNA; Plant Genetics and Genomics; Pleistocene; Pliocene; Population genetics; Population number; Primates; Research Article; Rivers
• ISSN: 1566-0621; 1572-9737
• DOI: 10.1007/s10592-010-0065-0

We used mtDNA sequence data from the Tana River red colobus and mangabey to determine how their population genetic structure was influenced by dispersal and habitat fragmentation. The colobus and mangabey are critically endangered primates endemic to gallery forests in eastern Kenya. The forests are a Pliocene-Pleistocene refugium that has recently undergone significant habitat loss and fragmentation due to human activities. We expected both primates to exhibit low levels of genetic diversity due to elevated genetic drift in their small populations, and to show a strong correspondence between genetic and geographic distance due to disruption of gene flow between forests by habitat fragmentation. Additionally, because mangabey females are philopatric, we expected their mtDNA variation to be homogeneous within forest patches but to be heterogeneous between patches. In contrast, colobus have a female-biased dispersal and so we expected their mtDNA variation to be homogeneous within and between forest patches. We found high levels of haplotype and nucleotide diversity as well as high levels of sequence divergence between haplotype groups in both species. The red colobus had significantly higher genetic variation than the mangabey did. Most of the genetic variation in both primates was found within forest fragments. Although both species showed strong inter-forest patch genetic structure we found no correspondence between genetic and geographic distances for the two primates. We attributed the high genetic diversity to recent high effective population size, and high sequence divergence and strong genetic structures to long-term habitat changes in the landscape.