Testing a global positioning system on free ranging badgers

Abstract

In the context of a study on the effects of landscape fragmentation on the ecology of a generalist carnivore, the European badger Meles meles, we deployed for the first time GPS (Global Positioning System) collars on this species. GPS need an unobstructed view to sky to find satellites signal and a reduced time of blinded period to reconstruct rapidly satellites ephemerid, in order to provide successful timed locations data (Tomkiewiecz et al. 2010). In the case of badgers that can spend as much as 70% of their time underground (Roper 2011), one may expect to face high probability of missing and inaccurate locations, leading to mistaken inference on spatial behaviour, especially those involving movement path and habitat selection (Frair et al. 2010). This can be compensated by increasing sampling frequency, yet at the expense of battery lifespan. In this paper, we aimed to assess the combined effects of the environment (forested versus agricultural) and animal behaviour (namely underground living pattern) on GPS data quality and quantity when deployed on free ranging badgers using two contrasted sampling of GPS data acquisition (fix sampling intervals) and two contrasted landscapes, by deploying GPS collars on individuals trapped around setts located in forested (>50% of wood cover) and agricultural (~10% of wood cover) landscapes. Our practical objective was to assess the compromise between the GPS life time (i.e. tracking duration) and the capacity to reveal fine scale movements and ultimately home range in badgers.