Identifying genetic relationships among tarsier populations in the islands of Bunaken National Park and mainland Sulawesi.

Eastern tarsiers (Tarsius tarsier complex) are small nocturnal primates endemic to Sulawesi Island and small adjacent islands of Indonesia. In 2004, the hybrid biogeography hypothesis predicted this species complex might contain 16 or more taxa, each corresponding to a region of endemism, based on: 1) geological evidence of the development of the archipelago, 2) biological evidence in the form of concordant distributions of monkeys and toads, and 3) the distribution of tarsier acoustic groups. Since then, 11 tarsier species have been recognized, potentially leaving more to be described. Efforts to identify these cryptic species are urgently needed so that habitat conversion, pet trade, and cultural activities will not render some species extinct before they are recognized. We gathered data to test the hypothesis of cryptic tarsier species on three volcanic islands in Bunaken National Park, North Sulawesi, namely Bunaken, Manadotua, and Mantehage, during May-August 2018. We sequenced individuals at 5 nuclear genes (ABCA1, ADORA3, AXIN1, RAG, and TTR) and made comparisons to existing genotypes at 14 mainland sites. Bayesian phylogenetic analyses revealed that island populations are genetically identical in all 5 genes, and formed a clade separated from the mainland ones. The eastern tarsiers first diverged from the western tarsiers approximately 2.5 MYA. The three island populations diverged from mainland tarsiers approximately 2,000-150,000 YA, due to either human activities or natural rafting. This study provides information for tarsier conservation, advances the understanding of biogeography of Sulawesi, and contributes to Indonesian awareness of biodiversity. Further quantitative genetics research on tarsiers, especially the island populations, will offer significant insights to establish more efficient and strategic tarsier conservation actions.

Conservation genetics of the Philippine tarsier: cryptic genetic variation restructures conservation priorities for an island archipelago primate.

Establishment of conservation priorities for primates is a particular concern in the island archipelagos of Southeast Asia, where rates of habitat destruction are among the highest in the world. Conservation programs require knowledge of taxonomic diversity to ensure success. The Philippine tarsier is a flagship species that promotes environmental awareness and a thriving ecotourism economy in the Philippines. However, assessment of its conservation status has been impeded by taxonomic uncertainty, a paucity of field studies, and a lack of vouchered specimens and genetic samples available for study in biodiversity repositories. Consequently, conservation priorities are unclear. In this study we use mitochondrial and nuclear DNA to empirically infer geographic partitioning of genetic variation and to identify evolutionarily distinct lineages for conservation action. The distribution of Philippine tarsier genetic diversity is neither congruent with expectations based on biogeographical patterns documented in other Philippine vertebrates, nor does it agree with the most recent Philippine tarsier taxonomic arrangement. We identify three principal evolutionary lineages that do not correspond to the currently recognized subspecies, highlight the discovery of a novel cryptic and range-restricted subcenter of genetic variation in an unanticipated part of the archipelago, and identify additional geographically structured genetic variation that should be the focus of future studies and conservation action. Conservation of this flagship species necessitates establishment of protected areas and targeted conservation programs within the range of each genetically distinct variant of the Philippine tarsier.

Asian primate species richness correlates with rainfall.

Previous studies of meta-analyses found significantly positive correlations between primate species richness and rainfall for Africa, Madagascar and the Neotropics, with the exception of Asia, leaving the open question whether that anomaly is the result of sampling bias, biogeography, or some other factor. This study re-examines the question using modelled data, with primate species richness data from the Southeast Asian Mammals Databank and rainfall data from the Climatic Research Unit. Data processing with Geographical Information Systems resulted in 390 sample points. Reduced major axis and ordinary least squares regressions were employed to examine the relationship for six regions, including the whole study area of Southeast Asia, and the subareas of Huxley West, Huxley East, Mainland Southeast Asia, Borneo, and Sumatra. The results showed a significant positive relationship between primate species richness and mean annual rainfall for Southeast Asia (r = 0.26, P<0.001). Comparing the results for the large islands and Mainland Southeast Asia showed that Sumatra had the highest correlation (r = 0.58; P<0.05). After controlling for the major biogeographic effect associated with Huxley's Line, our results showed that primate species richness is positively associated with mean annual rainfall in Southeast Asia. Our findings contrast to prior studies of meta-analyses that showed no relationship between rainfall and primate species richness in Asia, and thereby bring Asia into agreement with results showing significant positive correlations between rainfall and primate species richness everywhere else in the world. The inference is that previous anomalous results for Asia were result of sampling bias in the meta-analysis.