Consequences of rapid population decline on genetic diversity in a putatively extinct primate
Miss Waldron’s red colobus monkey (Piliocolobus waldroni) is arguably the most endangered primate in the world. First described in the 1930s, P. waldroni was found in lowland rainforest of eastern Ivory Coast and western Ghana before disappearing due to habitat loss and hunting. The last confirmed sighting of the monkey was in 1978, and despite occasional reports of vocalizations suggesting a handful of individuals may still exist, P. waldroni is generally considered extinct. In order to investigate whether genomic erosion played a role in the decline of this species, we sequenced the genome of one of the paratype specimens collected in 1933 as well as the last known remaining individuals collected from a hunted carcass in 2001. We compared genome-wide heterozygosity from these two timepoints to quantify genomic erosion experienced over the course of the species’ recognized existence. We determined that genome-wide heterozygosity remained high in the modern specimen. This result suggests that P. waldroni was not genetically depauperate near its end and retained high diversity through the time period of extirpation, likely because there was insufficient time for genomic erosion to take place. This result emphasizes the rapid rate at which this monkey declined. If activities -particularly hunting -responsible for the extirpation of this animal continue, many other species in West and Central Africa are likely to meet the same fate.