Settle Down! Ranging Behaviour Responses of Roe Deer to Different Capture and Release Methods.

Ulrika A Bergvall,A.J Mark Hewison,Falko Brieger,Nicolas Morellet,Marco Heurich,Benedikt Gehr,Sonia Saïd,Tomasz Borowik,Francesca Cagnacci,Maryline Pellerin,Petter Kjellander,Leif Soennichsen,Geir R Rauset,Max Kröschel,Peter Sunde,Johannes De Groeve

doi:10.3390/ani11113299

Abstract

Simple SummaryThe study of animal movement in wild, free ranging species is fundamental for advancing knowledge on ecosystem relationships and for conservation. The deployment of bio-logging devices to this purpose (often GPS-collars in large mammals) requires relatively invasive procedures, such as capture, handling and release. Capture and manipulation cause behavioural modifications that are largely understudied in wild species and may affect both the welfare of animals and the output of the studies. We evaluated post capture and release ranging behaviour responses of a small deer species (roe deer Capreolus capreolus) for five different capture methods across 14 study sites within the EURODEER collaborative project. Roe deer showed modifications in their movement behaviour, independently of the capture method. However, individuals recovered rapidly, converging towards the average behaviour within a relatively short interval of time (between 10 days and one month), demonstrating a general resilience to such stressful events. We encourage researchers to continually adapt capture and handling methods so as to minimize stress and prioritize animal welfare.The fitting of tracking devices to wild animals requires capture and handling which causes stress and can potentially cause injury, behavioural modifications that can affect animal welfare and the output of research. We evaluated post capture and release ranging behaviour responses of roe deer (Capreolus capreolus) for five different capture methods. We analysed the distance from the centre of gravity and between successive locations, using data from 14 different study sites within the EURODEER collaborative project. Independently of the capture method, we observed a shorter distance between successive locations and contextual shift away from the home range centre of gravity after the capture and release event. However, individuals converged towards the average behaviour within a relatively short space of time (between 10 days and one month). If researchers investigate questions based on the distance between successive locations of the home range, we recommend (1) initial investigation to establish when the animals start to behave normally again or (2) not using the first two to three weeks of data for their analysis. We also encourage researchers to continually adapt methods to minimize stress and prioritize animal welfare wherever possible, according to the Refinement of the Three R’s.

Highlights

Animal movements are shaped by evolutionary and ecological processes that can be researched through bio-logging [1]
We investigated post-capture and release ranging behaviour for a total of 478 roe deer captured for their first time (226 fawns, 82 yearlings and 255 adults, where 85 of the individuals were followed over two age classes as they transitioned from fawn to yearling, or from yearling to adult) from 13 roe deer populations across Europe (EURODEER collaboration project, https://eurodeer.org; Table 1)
The most parsimonious model describing variation in the distance between successive locations (AICcWt = 0.130) included the spline of days since capture, which differed among capture methods, while controlling for the log-transformed home range size (Table S2)

Summary

Introduction

Animal movements are shaped by evolutionary and ecological processes that can be researched through bio-logging [1]. Some authors have suggested that the understanding of the potentially deleterious effects of fitting these devices, including capture, handling and release, have not kept pace with the advances in the techniques themselves [6,7], several studies have addressed post capture and release behavioural responses. These studies focused on behaviours after the capture and release, such as grooming [8] physiological responses to the handling event [3,4], and ranging behaviour after capture [9,10]. Most of these studies showed a time-since-release effect in the behavioural metrics considered so that capture-and-release responses were hypothesised to be temporary, but in different ways between studies and species [9,10,11]

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