Saving the mountain bongo (Tragelaphus eurycerus isaaci): Assessment of the genetic status of captive bongos as a source for genetic reinforcement of wild populations

Fewer than 140 individuals of the rare and critically endangered mountain bongo (Trogelaphus eurycerus isaaci) remain in the wild. This population has eroded genetic diversity, with only two haplotypes detected with mitochondrial DNA markers. The genetic diversity of mountain bongos from the European Endangered Species Programme (EEP) was assessed for this study. Genetic diversity of 10 captive individuals was measured by sequencing a portion of the mitochondrial DNA control region; the resulting sequences were compared to published data from this subspecies and used to establish levels of haplotype-sharing between wild and captive populations. Our data show that captive mountain bongo populations harbour a rare haplotype that is found in less than 5% of individuals in some wild populations and is absent in others. The findings suggest that captive individuals harbour valuable genetic diversity, making them potentially valuable candidates for a reintroduction programme to help reinforce the gene pools of wild populations. We further propose a two-way approach that also involves introducing wild individuals into captive populations, with the goal of maintaining the genetic health of both in situ and ex situ populations.