Conservation priorities for two ungulate species in the subfamily Caprinae in Oman

Abstract

In this study, molecular genetic data of Arabian tahr and Nubian ibex alongside census data on Arabian tahr's abundance were analyzed. By combining these data, they complement each other to fully understand conservation management. To achieve this, we sampled wild Arabian tahr and Nubian ibex from Oman. The phylogenetic study was based on complete mitochondrial genomes of Arabian tahr (S0011) and Nubian ibex (SN02) together with available mitochondrion sequences in the caprinae tree on GenBank. Bioinformatically, PSMC (Pairwise Sequentially Markovian Coalescent) was used to infer the demographic history for both our samples. Furthermore, detection of Runs of Homozygosity (ROH) was analyzed and finally, both heterozygosity and heterozygosity ratio were examined. Census data on Arabian tahr from the northern Hajar mountains was only analyzed in this study to understand Arabian tahr occupancy outside protected areas. The phylogenetic analysis supports both Arabian tahr (S0011) and Nubian ibex (SN02) of being unique and having their own distinct lineages. The closest relatives to Nubian ibex (SN02) and Arabian tahr (S0011) are Alpine ibex (Capra ibex) and Aoudad/the Barbary sheep (Ammotragus lervia). PSMC analysis using Arabian tahr and Nubian ibex revealed that they did not go through a severe bottleneck phase. However, Arabian tahr had a small (Ne of ~1000) stable effective population size from ~1 million years ago till about ~ 20,000 years ago. Similarity, the Nubian ibex population maintained a low (Ne of ~1000) population size during the last glacial period but was about twice as large during the last interglacial. Only 31.5% (23) of the total camera traps (73) deployed detected Arabian tahr. The summed occupancy across 73 cameras was 25.29 and this suggests that they occur in one third (34%) of the study area outside protected areas. Furthermore, slope seemed to be used by Arabian tahr to gain access to shade and forage rather than rugged terrain.