Impact of prey occupancy and other ecological and anthropogenic factors on tiger distribution in Thailand's western forest complex. Issue 5 (18th February 2019)

• Record Type: Journal Article
• Authors: Duangchatrasiri, Somphot; Jornburom, Pornkamol; Jinamoy, Sitthichai; Pattanvibool, Anak; Hines, James E.; Arnold, Todd W.; Fieberg, John; Smith, James L. D.
• Is Part Of: Ecology and evolution. Volume 9:Issue 5(2019)
• Page Start: 2449
• Page End: 2458
• Publication Date: 2019-02-18
• Subjects: large landscape survey -- multiple scale occupancy -- Panthera tigris -- prey -- tiger -- Western Forest Complex; Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.4845
• Languages: English
• ISSNs: 2045-7758

Abstract

Abstract: Despite conservation efforts, large mammals such as tigers ( Panthera tigris ) and their main prey, gaur ( Bos gaurus ), banteng ( Bos javanicus ), and sambar ( Rusa unicolor ), are highly threatened and declining across their entire range. The only large viable source population of tigers in mainland Southeast Asia occurs in Thailand's Western Forest Complex (WEFCOM), an approximately 19, 000 km 2 landscape of 17 contiguous protected areas. We used an occupancy modeling framework, which accounts for imperfect detection, to identify the factors that affect tiger distribution at the approximate scale of a female tiger's home range, 64 km 2, and site use at a scale of 1‐km 2 . At the larger scale, we estimated the proportion of sites at WEFCOM that were occupied by tigers; at the finer scale, we identified the key variables that influence site‐use and developed a predictive distribution map. At both scales, we examined key anthropogenic and ecological factors that help explain tiger distribution and habitat use, including probabilities of gaur, banteng, and sambar occurrence from a companion study. Occupancy estimated at the 64‐km 2 scale was primarily influenced by the combined presence of all three large prey species, and 37% or 5, 858 km 2 of the landscape was predicted to be occupied by tigers. In contrast, site use estimated at the scale of 1 km 2 was most strongly influenced by the presence of sambar. By modeling occupancy while accounting for imperfect probability of detection, we established reliable benchmark data on the distribution of tigers in WEFCOM. This study also identified factors that limit tiger distributions; which managers can then target to expand tiger distribution and guide recovery elsewhere in Southeast Asia. Abstract : This research presents the results of a multiple scale occupancy analysis of one of the largest tiger landscapes, the 19, 000 km 2 Western Forest Complex in Thailand. Despite its population is the best in Thailand and the large area that it occupies, tigers are estimated to occupy < half of this landscape. Our analysis demonstrates that the presence of the combination of all large mammals is the primary predictor on tiger occupancy at the approximate scale of a female tiger's home range (64 km 2 ), but at a finer grain of site use (1 km 2 ), sambar is primary predictor of habitat use.