Camera-trapping reveals globally threatened mammalian biodiversity in Mindoro, Philippines

The island of Mindoro, Philippines, is a biodiversity hotspot with numerous endemic and threatened species, including mammals like the tamaraw Bubalus mindorensis and Oliver’s warty pig Sus oliveri . Unfortunately, mammals in Mindoro are threatened by poaching, habitat loss, and expanding infrastructure. To develop effective conservation plans to protect these species, it is important to have up-to-date information on their population status in key areas. From December 2020 to May 2022, we conducted semi-structured camera-trapping in the Aruyan-Malati region, a forest area located in the Municipality of Sablayan, in Occidental Mindoro. Total camera-trapping effort was 1889 camera-trap nights from 73 stations. We identified a total of 6 mammal species, including tamaraw, Oliver’s warty pig, common palm civet Paradoxurus hermaphroditus , long-tailed macaque Macaca fascicularis , and domestic dogs and cats, but we failed to record Philippine deer Rusa marianna, despite indications that the species was previously present in the area. To inform future camera-trapping in future surveys in other parts of Mindoro, we estimated detection probability for the mammal species and scaled this by camera-trapping effort. The fact that we recorded a relatively intact mammal community, including both tamaraw and Oliver’s warty pig, suggests that Aruyan-Malati harbors globally important mammalian biodiversity. Future conservation efforts should focus on strengthening site security and minimizing the potential adverse effects of domestic dogs and cats.