Physiological and behavioural impact of trapping for scientific purposes on European mesocarnivores

Abstract

Wildlife trapping and handling entails multi-level consequences on captured individuals. These impacts may be expressed at the physiological and behavioural levels, starting at capture and potentially waning post-release over a variable period. We investigated the impact of trapping and handling on the physiological parameters of 6 species of southwestern European mesocarnivores from the families Canidae, Felidae, Mustelidae, Herpestidae, and Viverridae. These parameters were quantified in real time during the handling procedures, after the induction of chemical immobilization. Using a time-step approach, we further assessed the impact of trapping on the movement behaviour of a subsample of the mesocarnivores. A total of 195 mesocarnivores were captured with cage traps or neck snares, and aspects of their haematology, and blood chemistry parameters quantified in a subset of the cage-trapped animals. These biomarkers suggested mild dehydration, tissue damage, exertion, and activation of the immune response as consequences of live trapping. Eight European wildcats (Felis silvestris), 4 red foxes (Vulpes vulpes), and 4 stone martens (Martes foina) were also fitted with GPS-VHF radio-collars, and their movements tracked by conventional ground-based VHF and GPS telemetry. Movement behaviour was assessed as the mean distance to trapping sites over each week of monitoring and compared with the value under normal use of their home ranges (set as >13 wks post-capture). Our results showed evidence of reduced movements for up to 5 wks post-capture. Selected haematology, serum chemistry, anaesthesia monitoring, and movement behaviour parameters should become standard biomarkers of the reactive homeostatic response to live trapping, offering a finer comparison of live-capture techniques and protocols.