Initial terrestrial vertebrate diversity assessment in upland Cavite, Philippines

Abstract

Cavite’s remaining upland forest fragments are either remnant from commercial logging activities ca. 25-45 years ago or as a direct result of land conversions for agriculture or human settlements. These forest fragments are very significant because they represent areas where pockets of wildlife habitat still remain. The terrestrial vertebrates are often used to assess animal diversity because they are ideal biological indicators of environmental change and anthropogenic disturbances. The study aimed to determine terrestrial vertebrate diversity, conservation status, and identify major anthropogenic threats in these fragments. Terrestrial vertebrates were surveyed using a combination of strip-transect sampling, time-constrained searches, visual encounter survey (VES), and acoustic encounter survey (AES; for amphibians only), point counts, live trapping and mist netting from October 2014 to March 2016. Species richness and biodiversity estimation were computed using Shannon-Wiener Diversity Index, linear regression, detection and probability modeling using PAST, and confidence limits for nestedness (0.05α) using EpiTools. A total of 175 terrestrial vertebrates were documented and among the vertebrate groups, the birds had the highest observed diversity. Twenty-nine (19 birds, 3 mammals, 3 lizards, and 4 anurans) species are listed as threatened. Habitat loss and degradation due to the conversion of habitats to agricultural and/or residential areas remained to be the most prevalent threat in the remaining forested areas in upland Cavite. Baseline data generated shall be used in the different government biodiversity monitoring activities as the basis for impacts and mitigation and initial planning for the management and conservation of these remaining forest patches.