Tiger density, dhole occupancy, and prey occupancy in the human disturbed Dong Phayayen – Khao Yai Forest Complex, Thailand

Abstract

Large carnivores have been declining due to a combination of factors including habitat loss and fragmentation, prey loss, and direct persecution. Tiger Panthera tigris and dhole Cuon alpinus are endangered and emblematic of problems facing large carnivores globally. We estimated tiger density, dhole occupancy and prey availability within the Dong Phayayen - Khao Yai Forest Complex, a World Heritage Area in Thailand that has potential as a ‘recovery site’ for both species. Camera traps were set near bait stations designed for bear monitoring. A Bayesian spatial capture-recapture approach was used to estimate tiger density and occupancy of dhole and their prey. Camera traps were deployed in two areas, Khao Yai (78 locations, December 2009-May 2011) and Dong Phayayen (45 locations, December 2012-August 2014). Tiger was not detected in Khao Yai. We detected 9 tigers (2 male, 4 females, and 3 unknown sex) in Dong Phayayen. Tiger density was 2.1 (95% CI 0.5–5.3) individuals per 100 km2 based on an individual heterogeneity model. Dhole occupancy was higher in Khao Yai (64%) than Dong Phayayen (55%). Prey occupancy was 9–53% higher in Dong Phayayen. Wild pig Sus scrofa had the highest occupancy rates, followed by gaur Bos gaurus, sambar Rusa unicolor and muntjac Muntiacus muntjac, respectively. Although Dong Phayayen’s tiger density was lower compared to populations estimated in some better-known protected areas, our data suggest it has potential as a regional tiger (and perhaps dhole) recovery site. However, Dong Phayayen, like many sites in the region, faces significant threats from wildlife hunting and rosewood (Dalbergia spp.) poaching that need to be addressed urgently if this small population is going to survive even the near term.