Jaguar predation on domestic horses in the dry forest of northwestern Costa Rica

Abstract

Depredation of domestic horses (Equus caballus) by jaguars (Panthera onca) is an example of human–wildlife conflict that has not received much attention. We monitored spatio-temporal activity and distribution of horses in a 2.64-km² fenced area in the dry forest of northwestern Costa Rica in response to 16 jaguar killings of horses during January-November 2017. We monitored 4 horses (2 males, 2 females) equipped with global positioning system transmitters from February-September 2018 to identify daily and seasonal patterns of use of cover types and a water source by horses. We then compared these results to the previous locations where jaguars killed horses to identify the circumstances under which horses seemed more vulnerable to jaguar predation. Based on 1,693 locations, horses spent most time in grassland (92%) rather than forest and edge vegetation (8%) and used a core area of 0.74 km² (kernel density estimation) to 0.86 km² (minimum convex polygon). Of 16 horse predation events by jaguars, 9 events (56%) occurred in grasslands, 4 in forested areas (25%), and 3 in the forest edge (19%), indicating predation events occurred disproportionately from expected counts based on horse use of vegetation. The predation sites were characterized by a higher proportion of edge and a lower proportion of forest compared to a random points. We suggest that when horses explored areas near the edge of forested areas, the chances of being preyed on by jaguars increased.