Distribution and genetic diversity of the Endangered Abbott's duiker Cephalophus spadix in the Udzungwa Mountains, Tanzania

Abstract

Abbott's duiker Cephalophus spadix is a forest antelope endemic to a very few highland forests in Tanzania. Apparently extinct over much of its historical range, the species is listed as Endangered by the International Union for Conservation of Nature based on its rarity and its known current distribution in only 5 isolated upland areas: Kilimanjaro, Southern Highlands, West Usambara, Rubeho and Udzungwa Mountains. In contrast to the situation in the rest of its range, Abbott's duiker is relatively well documented and locally abundant in parts of the Udzungwa Mountains, which may now be the only stronghold for the species. We review the distribution of Abbott's duiker within the Udzungwa Mountains and present new information based on the noninvasive genetic identification of dung piles collected from the majority of forest blocks between 2006 and 2010 (73 confirmed dung samples). Our results include new records from outlying forest blocks where the presence of Abbott's duiker was previously unknown. Moreover, we present the first population-level analysis of genetic structure and diversity in this endangered species based on nuclear microsatellites and mitochondrial sequence data. While these genetic results are limited due to small sample sizes, they indicate differentiation from other Abbott's duiker populations, as well as low genetic diversity relative to sympatric antelope species. Finally, we discuss threats to Abbott's duiker and identify broad trends within the differently managed Udzungwa Mountain forests, and elsewhere, that suggest potentially successful conservation strategies for this neglected species.