Scared as a hare: effects of capture and experimental disturbance on survival and movement behavior of European hares

Martin Mayer,Peter Sunde,Lars Haugaard

doi:10.2981/wlb.00840

Abstract

Capture and handling of wildlife is an important component of wildlife studies, and hunting can be a central tool for wildlife management. However, human-caused disturbance of animals can cause various negative effects on individuals. Thus, an increased understanding of different disturbances on animals will allow improved mitigation of human stressors for wildlife, and provides the basis for data-censoring when using information obtained from captured individuals. Here, we investigated the effects of capture and handling, as well as experimental disturbance, on the movement behavior of GPS-collared European hares Lepus europaeus. Of 28 hares captured in box traps, three died during handling to fit GPS collars, likely due to acute stress. Apart from an 11% decrease in activity in both sexes the first four days after capture compared to later, capture events had no significant effects on subsequent movement behavior. Hares that were disturbed experimentally, i.e. flushed with or without a shotgun shot fired, moved on average (± SD) 422 ± 206 m directly subsequent to the disturbance, leading to a spatial displacement of their short-term home range and an increased daily home range size on the disturbance day. Home range sizes returned to their before disturbance size on the following days, but hares remained further from field edges and spent more time in short vegetation in the days after simulated hunting, though this effect was comparatively small. Overall, our findings indicate that hares only marginally changed their movement behavior in response to short-term disturbances. Therefore, capture and hunting disturbance should not have severe negative effects on the movement behavior of individuals, but future studies should aim to reduce acute capture-related stress to avoid mortalities. We recommend that researchers should censor the first four days after capture from their analyses to avoid using potentially biased data.

Highlights

Human-caused disturbance can induce stress in wildlife, e.g. leading to reduced breeding success, displacement from preferred feeding areas, changes in activity times and in some cases reduced survival (Rodriguez-Prieto and FernandezJuricic 2005, Kight and Swaddle 2007, Ciuti et al 2012, Gaynor et al 2018)
Bio-logging devices, such as GPS and accelerometers, can be very useful to study the effects of human-caused disturbance, because they greatly improve our understanding of animal movement, and behavior (Hebblewhite and Haydon 2010, Foley and Sillero-Zubiri 2020)
Males had larger daily home ranges (95% kernel density estimates (KDE)) than females, but home range size did not change in the days after capture (Supporting information)

Summary

Introduction

Human-caused disturbance can induce stress in wildlife, e.g. leading to reduced breeding success, displacement from preferred feeding areas, changes in activity times and in some cases reduced survival (Rodriguez-Prieto and FernandezJuricic 2005, Kight and Swaddle 2007, Ciuti et al 2012, Gaynor et al 2018). Bio-logging devices, such as GPS and accelerometers, can be very useful to study the effects of human-caused disturbance, because they greatly improve our understanding of animal movement, and behavior (Hebblewhite and Haydon 2010, Foley and Sillero-Zubiri 2020). The capture, handling and tagging of individuals for research in itself are a source of disturbance that can cause stress and altered energy. Apart from capture and handling for research, another substantial type of human-caused disturbance is hunting, leading to altered behavior and space use (Sunde et al 2009, Chassagneux et al 2019). Individuals can respond toward spatio–temporal variation in predation risk (including hunting) via altered time allocation and vigilance (Lima and Dill 1990, Kotler et al 2002) That is, they can choose when, and where to be active, e.g. by adjusting their daily home range size and location or by selecting for different habitat types, and by altering activity budgets to reduce predation risk (Kotler et al 2004)

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Conclusion