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Badger Survey of England and Wales - SE3129

Description
Obtaining an up-to-date estimate of the current size of the badger population will help inform policy on badgers and will assist the UK in addressing its obligations under the Bern Convention. The last National Badger Survey of Great Britain was completed in 1997 and was a follow-up to the original survey carried out in the mid 1980s. The 1990s survey revealed that badger numbers had increased substantially in the intervening decade. There is a commonly held perception that the badger population has continued to increase since then. Surveys of the badger population in Northern Ireland and Scotland were conducted in 2008. In order to provide updated estimates of the UK badger population, we need information on the size of the badger population in England and Wales. To address this need we propose to carry out a new survey of England and Wales in 2011-13.
Badgers in southern Britain tend to live in social groups within a shared territory. Within a territory, there tends to be one, distinct main sett. Badger main setts were used as a proxy for the presence of a badger social group in the previous two national surveys of Britain, and this approach has also been used in similar surveys in Ireland. The survey will require repeat surveys of the 1-km squares which comprised the previous surveys in the 1980s and 1990s. These squares are a representative sample of the landscape types in England and Wales. Repeating these original survey squares will provide the most powerful means to quantify any changes that have occurred since the last survey.
Each 1-km square will be completely resurveyed and all badger setts will be mapped. Surveys will be carried out by professional surveyors during the autumn, winter and spring (1st November to 31st March) when vegetation is at its lowest and badger setts are easier to find. Setts will be classed as main setts or other setts. The sett locations will be entered into a Geographical Information System overlaid with the Centre for Ecology and Hydrology’s Land Cover Map in order to accurately assign habitat type / land class to sett locations and survey squares. This will provide a basis for exploring habitat and landscape determinants of badger sett location and density.
The density of main setts found in the sample squares will be used to derive estimates of the total abundance of social groups by extrapolating from sample data by land class group. This is the approach taken in previous surveys. Analysis of population change will be based on comparison of all three surveys in a single statistical model using the presence/absence and abundance of social groups as the main response variable. Estimates of social group abundance can be converted to an estimate of the number of badgers by multiplying by an appropriate mean badger social group size. These data are currently being collated as part of a Defra-funded project (SE3128). The GIS that we will develop will also be available as a tool to assess/predict regional badger populations.
Objective
1. To conduct a repeat field survey of badger setts in approximately 1700 1km squares that were surveyed in the 1980s and 90s
2. To produce estimates of the number of badger social groups in 2011-2013
3. To assess change in the number of social groups since the 1980s and the 1990s, if any
4. To produce estimates of the badger population of England and Wales, and of the UK
5. To build and make accessible a GIS for the estimation of badger populations at a regional scale
Time-Scale and Cost
From: 2011

To: 2013

Cost: £870,984
Contractor / Funded Organisations
F E R A (FERA)
Keywords
Tuberculosis              
Fields of Study
Animal Health