Reduced occupancy of hedgehogs (Erinaceus europaeus) in rural England and Wales: The influence of habitat and an asymmetric intra-guild predator

Ben M Williams,Richard W Yarnell,Gavin Wilson,Johanna Judge,Emily Thomas,Philip J Baker

doi:10.1038/s41598-018-30130-4

Abstract

Agricultural landscapes have become increasingly intensively managed resulting in population declines across a broad range of taxa, including insectivores such as the hedgehog (Erinaceus europaeus). Hedgehog declines have also been attributed to an increase in the abundance of badgers (Meles meles), an intra-guild predator. The status of hedgehogs across the rural landscape at large spatial scales is, however, unknown. In this study, we used footprint tracking tunnels to conduct the first national survey of rural hedgehog populations in England and Wales. Single and two-species occupancy modelling was used to quantify hedgehog occupancy in relation to habitat and predator covariates. Hedgehog occupancy was low (22% nationally), and significantly negatively related to badger sett density and positively related to the built environment. Hedgehogs were also absent from 71% of sites that had no badger setts, indicating that large areas of the rural landscape are not occupied by hedgehogs. Our results provide the first field based national survey of hedgehogs, providing a robust baseline for future monitoring. Furthermore, the combined effects of increasing badger abundance and intensive agriculture may have provided a perfect storm for hedgehogs in rural Britain, leading to worryingly low levels of occupancy over large spatial scales.

Highlights

Habitat loss is one of the main threats to global biodiversity and the key cause of species loss in terrestrial ecosystems[6,7,8], and has been driven principally by the increased intensity of agricultural production[9,10,11,12,13]
Rural landscapes are further fragmented by road networks which could potentially act as a significant source of mortality and a barrier to movement[24,25]
The total length of roads per survey square ranged from 0.00–6.78 km: the majority of roads were classified as minor (MINORROADS: 1.34 ± 0.07 km), followed by A-roads (AROADS: 0.20 ± 0.03 km) and, B-roads (BROADS:0.14 ± 0.02 km); MOTORWAY accounted for the lowest density (0.02 ± 0.01 km)

Summary

Introduction

Habitat loss is one of the main threats to global biodiversity and the key cause of species loss in terrestrial ecosystems[6,7,8], and has been driven principally by the increased intensity of agricultural production[9,10,11,12,13]. In the UK, one of the hedgehog’s preferred habitats, grassland, has declined in area since the 1950s15 Such changes have had detrimental impacts on a range of taxa[9,13,16,17] and are likely to have negatively affected hedgehog populations www.nature.com/scientificreports/. We utilise that method to conduct the first national scale survey of rural hedgehog populations to: (i) measure levels of occupancy across rural England and Wales; and (ii) investigate relationships between habitat availability, predator abundance and patterns of occupancy. These data can (iii) be used as a baseline against which future changes can be measured

Methods

Results

Conclusion