Abundance of badgers (Meles meles) in England and Wales

Johanna Judge,Richard J Delahay,Gavin J Wilson,Roy Macarthur,Robbie A Mcdonald

doi:10.1038/s41598-017-00378-3

Abstract

The European badger (Meles meles) is of considerable interest in the UK as it is both a protected species and the main wildlife reservoir for bovine tuberculosis infection in cattle. While there have been three national badger surveys in the 1980s, 1990s and 2011–13, using the number of badger main setts as a proxy for the abundance of badger social groups, none has combined contemporary data on social group size at landscape and national scales. We estimated social group size by genotyping hair samples collected at 120 main setts across England and Wales and employing a capture-mark-recapture method based on genotypes. The estimated mean social group size in England and Wales was 6.74 (±0.63) badgers. There was considerable variation in badger social group size among Land Class Groups (LCGs), with a low of 2.67 in LCG3 and a high of 7.92 in LCG4. Combining these results with the recent Badger Sett Survey of England and Wales, we estimate there are approximately 485,000 badgers (95% confidence intervals 391,000–581,000) in England and Wales. Although direct comparison with previous estimates is not ideal owing to methodological differences, our results are consistent with a marked increase in the badger population of England and Wales since the 1980s.

Highlights

The European badger (Meles meles) has been the focus of significant research interest and political debate in the United Kingdom
During the 2011–13 badger sett survey of England and Wales[9] no main setts were recorded in any of the 29 squares surveyed in Land Class Group 7, it was not possible to set hair traps in this Group
Combining our estimates of badger social group sizes with the estimated number of social groups from the recent sett survey of England and Wales[9] yielded an estimate of the total badger population in England and Wales in 2011–14 of 485,000 (95% confidence interval 391,000–581,000), and an overall density of 3.29 badgers/km[2]

Summary

Introduction

The European badger (Meles meles) has been the focus of significant research interest and political debate in the United Kingdom. Estimates of badger population size have used published data from a small range of studies as a multiplier to derive population estimates from sett survey data[5, 6] These studies were not all contemporary with, nor fully representative of the geographical area or landscapes covered by, the sett surveys. In a long-term study of badgers in Sussex, the number of main setts and associated badger social groups more than doubled over a 20 year period, while social group territory sizes halved[15]. We conducted hair trapping and genotyping to generate contemporary estimates of mean badger social group sizes for areas of England and Wales that had been part of our 2011–13 badger sett survey[9].

Methods

Results

Conclusion