Safe Passage or Hunting Ground? A Test of the Prey-Trap Hypothesis at Wildlife Crossing Structures on NH 44, Pench Tiger Reserve, Maharashtra, India

Abstract

Crossing structures are widely accepted mitigation measures used to offset the impacts of roads in ecologically sensitive areas that serve as important animal corridors. However, altered interspecies interactions at crossing structures may reduce the potency of these structures for some species and groups. Anecdotes of predation events at crossing structures have necessitated the assessment of predator–prey interactions at crossing structures. We investigated the ‘prey-trap’ hypothesis at nine crossing structures on a highway in central India adjacent to a tiger reserve by comparing the geometric mean latencies between successive prey, predator and free-ranging dog camera trap capture events at the crossing structures. Among all interactions, prey–predator latencies were the shortest, and significantly lower than prey–dog and predator–prey latencies. Prey–predator sequences involving wild dogs had the shortest average latencies (65.6 ± 9.7 min). Prey–predator latencies decreased with increasing crossing structure width; however, these crossing structures are also the sites that are most frequently used by wildlife. Results indicate that the crossing structures presently do not act as ‘prey-traps’ from wild predators or free-ranging dogs. However, measures used to alleviate such prospects, such as heterogeneity in structure design and increase in vegetation cover near crossing structures, are recommended.