Landscape‐scale accessibility of livestock to tigers: implications of spatial grain for modeling predation risk to mitigate human–carnivore conflict

Abstract

Innovative conservation tools are greatly needed to reduce livelihood losses and wildlife declines resulting from human–carnivore conflict. Spatial risk modeling is an emerging method for assessing the spatial patterns of predator–prey interactions, with applications for mitigating carnivore attacks on livestock. Large carnivores that ambush prey attack and kill over small areas, requiring models at fine spatial grains to predict livestock depredation hot spots. To detect the best resolution for predicting where carnivores access livestock, we examined the spatial attributes associated with livestock killed by tigers in Kanha Tiger Reserve, India, using risk models generated at 20, 100, and 200-m spatial grains. We analyzed land-use, human presence, and vegetation structure variables at 138 kill sites and 439 random sites to identify key landscape attributes where livestock were vulnerable to tigers. Land-use and human presence variables contributed strongly to predation risk models, with most variables showing high relative importance (≥0.85) at all spatial grains. The risk of a tiger killing livestock increased near dense forests and near the boundary of the park core zone where human presence is restricted. Risk was nonlinearly related to human infrastructure and open vegetation, with the greatest risk occurring 1.2 km from roads, 1.1 km from villages, and 8.0 km from scrubland. Kill sites were characterized by denser, patchier, and more complex vegetation with lower visibility than random sites. Risk maps revealed high-risk hot spots inside of the core zone boundary and in several patches in the human-dominated buffer zone. Validation against known kills revealed predictive accuracy for only the 20 m model, the resolution best representing the kill stage of hunting for large carnivores that ambush prey, like the tiger. Results demonstrate that risk models developed at fine spatial grains can offer accurate guidance on landscape attributes livestock should avoid to minimize human–carnivore conflict.

Livestock losses and hotspots of attack from tigers and leopards in Kanha Tiger Reserve, Central India

“…The locations of these sites were determined by generating random points stratified across a 200-m grid in ArcGIS, with one point per pixel separated by at least 200 m so as not to repeatedly sample the same area. While ground-surveying these random sites for another study (Miller et al 2015), no wild or domestic prey carcasses were observed.…”

“…To obtain more detailed spatial, temporal, and demographic data on the livestock killed, we conducted ground surveys of freshly killed livestock reported for compensation from December 2011 through August 2012. Sampling methods are described in detail in Miller et al (2015) and overviewed here.…”

“…We then calculated the Euclidean distance between the center of each kill site pixel and the center of the nearest pixel with the landscape attribute. We limited our study area to within 4 km of village centers in the reserve since no livestock were killed beyond this distance (Miller et al 2015).…”

“…livestock husbandry techniques (Wikramanayake et al 1998;Miller 2015). Many previous studies on humancarnivore conflict have focused on depredation by a single carnivore species (usually a high-priority species of conservation concern) on all livestock species generally, which can obscure unique risk gradients for individual livestock species from specific carnivores (Treves et al 2011;Lichtenfeld et al 2014;Athreya et al 2014;Miller et al 2015).…”

Troublemaking carnivores: conflicts with humans in a diverse assemblage of large carnivores

“…However, large carnivores also pose many real and perceived threats to people and communities that live within carnivore home ranges. Carnivores can kill livestock and pets (e.g., Naughton- Treves et al 2003, Morehouse and Boyce 2011, Miller et al 2015, cause property damage (e.g., Wilson et al 2006, Treves 2009), affect cattle weight gain (Ramler et al 2014), and pose a risk to human safety (e.g., Treves andNaughton-Treves 1999, Ratnayeke et al 2014). Although separating people and carnivores at small scales, e.g., exclusion from calving pastures or yard sites, often is desirable, the separation model is unrealistic at larger scales where there is not enough space for carnivores if they are restricted from humansettled lands (e.g., Woodroffe andGinsberg 1998, Chapron et al 2014).…”