An initial assessment of the sustainability of waterbird harvest in the United Kingdom

• Published in: Journal of Applied Ecology
• Main Authors: Ellis, Matthew B., Cameron, Tom C.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2022
• Subjects: Canada; Woodcock; Branta canadensis
• Online Access: http://dx.doi.org/10.1111/1365-2664.14281; https://onlinelibrary.wiley.com/doi/pdf/10.1111/1365-2664.14281; https://onlinelibrary.wiley.com/doi/full-xml/10.1111/1365-2664.14281; https://besjournals.onlinelibrary.wiley.com/doi/pdf/10.1111/1365-2664.14281

Abstract There is a need to assess the sustainability of wild bird harvest in the United Kingdom (UK), and more widely, across Europe. Yet, data on populations and harvest sizes are limited. We used a demographic invariant method (DIM) to estimate potential excess growth (PEG) for populations of UK wintering waterbirds and calculated a sustainable harvest index (SHI) for each. We compared this with population trends and conservation classifications (e.g. Birds of Conservation Concern [BoCC]) to assess the sustainability of harvests and the utility of these classifications. Our approach found evidence for potential overharvest of mallard Anas platyrhynchos , Eurasian teal Anas crecca , gadwall Mareca strepera , Canada geese Branta canadensis , greylag geese Anser anser and woodcock Scolopax rusticola . Whether DIM methods predict overharvest is highly dependent on estimates of maximum population growth rates inferring PEG. We found estimates of maximum population growth to be variable across a range of different methods. We found no relationship between SHI and short‐term wintering trends or conservation classification under the UK's BoCC framework. There was however a positive relationship between SHI and long‐term wintering trends. Policy implications . Our results suggest that UK‐based harvest is unlikely to be a major determinant of population trends for the majority of UK overwintering waterbirds, but harvest rates for some species may exceed that required to maintain stationary population growth. The lack of a relationship between conservation classifications and SHI strongly suggests that such conservation classifications are not an appropriate tool for making decisions about harvest management. Instead, our assessment provides the basis for a framework to make evidence‐based decisions on sustainable harvest levels in the face of incomplete data. There is currently no clear policy instrument in the UK to support such a framework via controls on either harvest effort or mortality of waterfowl. We believe ...