Ecological Covariates at Kill Sites Influence Tiger (Panthera tigris) Hunting Success in Huai Kha Khaeng Wildlife Sanctuary, Thailand

Abstract

Despite significant knowledge of tiger ecology, information on hunting behavior is limited because tigers hunt in habitats where they are difficult to observe. From May 2013 to June 2015, we visited kill sites of eight female radio-collared tigers (Panthera tigris) to identify prey species of this species in Huai Kha Khaeng Wildlife Sanctuary, Thailand. At 150 kill sites, 11 mammalian species were identified from skeletal remains or hair samples. Sambar (Rusa unicolor), banteng (Bos javanicus), and gaur (Bos gaurus) composed 95.1% of tiger prey biomass. A subset of 87 kill sites was paired with 87 randomly selected sites within the home ranges of five of the eight radio-collared tigers to determine the influence of prey abundance and other ecological variables on hunting success. At each site, geomorphic and ecological covariates were sampled in 900 m 2 square plots. A generalized linear model was used to investigate differences between kill sites and random sites. Mean relative prey abundance at kill sites was significantly lower than relative prey abundance at random sites (77.8 and 139.3 tracks/ha, respectively) indicating tigers did not kill in areas of higher relative prey abundance. Model selection was used to examine 12 landscape features that potentially influence kill site location. In the best model, low shrub cover and high crown cover were highly significant; tree density was included in this model but was not significant. This is the first study to demonstrate that kill location requires a combination of landscape features to first detect and then successfully stalk prey. Keywords cluster locations, Huai Kha Khaeng Wildlife Sanctuary, hunting success, tiger kill site characteristics, tiger prey Animals should seek habitat with adequate food, cover, nest/den sites, or other resources critical for survival (Manly, McDonald, Thomas, McDonald, & Erickson, 2002). For female felids, sufficient food to raise young is often their primary resource need, and natural selection is expected to drive foraging decisions to optimize food intake and minimize energy expenditure (Krebs & Davies, 1993). Food demands of female tigers increase rapidly as cubs mature and mothers continue to be the primary provider until their young are approximately 1.5 years old; at this time, male offspring are often larger than their mothers (Smith, McDougal, & Miquelle, 1989). Johnson (1980) proposed a hierarchical model as a framework by which animals efficiently meet their resource needs. Simcharoen et al. (2014) studied second order habitat selection which focuses on where female tigers settle and the relationship of prey abundance to their territory size. These authors found an inverse relationship between female territory size and

Impact of prey occupancy and other ecological and anthropogenic factors on tiger distribution in Thailand's western forest complex

“…From November 2010 to December 2012, Thailand's Department of National Parks, Plants, and Wildlife Conservation (DNP), the Wildlife Conservation Society (WCS, Thailand), and the World Wildlife Fund (WWF, Thailand) conducted an occupancy survey that included elephants ( Elephus maximus ), tigers and the main prey of tigers: banteng ( Bos javanicus ), gaur ( Bos gaurus ), and sambar ( Rusa unicolor ) in the Western Forest Complex (WEFCOM) (Figure ). Collectively, these three large ungulates comprise 88%–95% of the tiger's prey in WEFCOM (Pakpien et al, ; Simcharoen et al, ). This landscape covers 19,600 km 2 and consists of 17 contiguous protected areas making it the largest intact protected area in Thailand and all of southern Asia (Figure ).…”

“…(Figure 1). Collectively, these three large ungulates comprise 88%-95% of the tiger's prey in WEFCOM (Pakpien et al, 2017;Simcharoen et al, 2018). This landscape covers 19,600 km 2 and consists of 17 contiguous protected areas making it the largest intact protected area in Thailand and all of southern Asia (Figure 1).…”

Geology and discovery record of the Trinil Pithecanthropus erectus site, Java

“…Around 250 of these cattle still reside in the forests of one mountain sanctuary in Thailand, where the animals browse as needed on shrubs, herbs and tree bark in the dry season, for example, and co-exist with the Gaur (an oxen), Asian Wild Buffalo, Sambar ( Rusa deer ), Sumatran Serow, muntjacs, Clouded Leopard, Sun Bear, and Tiger, among other forest species (Prayurasiddhi 1997). Banteng is one of two large-bodied prey species of the robust tiger population there (Pakpien et al 2017). Thousands of wild Bos javanicus also thrive primarily on grasses in the dry-deciduous forests in eastern Cambodia (Duckworth et al 1999, Gray and Phan 2011, Gray et al 2012, 2016, Nguyen 2009, Steinmetz 2004).…”

“…Tigers still inhabit Sumatra, where they prefer thick understory, and prey, by surprise and stealth, on medium- to large-ungulates and ground-dwelling primates, such pigs, muntjacs, deer and macaques (e.g., Goodrich et al 2015, Linkie et al 2008, Wibisono et al 2011). A robust tiger population in a Thai mountain reservation preys on Banteng and another large-bodied bovid species (Pakpien et al 2017). The Trinil dog Xenocyon trinilensis Stremme, 1911 is the only other large carnivore known from Trinil.…”

Weights of gaur (Bos gaurus) and banteng (Bos javanicus) killed by tigers in Thailand

“…An additional 12 species constitute the other 9.7% of the diet (Simcharoen et al, 2018). Pakpien et al (2017) documented 11 of the tiger's 16 known prey species at kill sites. Our study site coincided geographically with these two research locations.…”