Citation
Austin, G., Frost, T., Mellan, H. & Balmer, D. 2017. Results of the third Non-Estuarine Waterbird Survey, including Population Estimates for Key Waterbird Species. BTO Research Report 697: British Trust for Ornithology, Thetford
Overview
During December, January and February of the winter of 2015/16, BTO organised the third Non-estuarine Waterbird Survey (NEWS III), the fourth in a series of coordinated winter surveys of the non-estuarine coast of the UK. This report presents the findings of this survey.
In more detail
- The basic field-work methodology has remained unchanged across all four surveys (the previous ones being the Winter Shorebird Count in 1984/85, NEWS I in 1997/98 and and NEWS II in 2006/07. The data recorded and the manner in which they have been collated has evolved to allow more robust estimates of waterbird numbers to be made. These changes have implications when it comes to making comparisons between the surveys. A brief overview of the four surveys is therefore provided.
- This document reports population estimates of key bird species on the non-estuarine coast of the UK and its constituent countries, Great Britain and crown dependencies during the winter of 2015/16. These new population estimates for waders, and where appropriate similar estimates for wildfowl, will feed directly into revised population estimates for wintering waterbirds that are in preparation.
- NEWS III achieved 53% coverage of the non-estuarine coast of the UK, an improvement on 44% for NEWS II.
- Counters were also asked to score the extent of deposits of beach-case seaweed, enabling estimates of relative amounts of this resource to be produced. Areas with the highest amounts of beach-cast seaweed included Ards in Northern Ireland, Anglesey in Wales, and Shetland, Orkney and West Scotland.
- A total of 217 bird species/sub-species/races and 18 mammal species were recorded during the survey.
- A bootstrap approach was used to derive regional (county) estimates of the populations of 43 key coastal waterbird species to be found on the non-estuarine coast during the winter of 2015/16 and during the three previous surveys. These in turn were used to derive separate estimates for the UK and each of its four constituent countries, Great Britain and crown dependencies.
- Population estimates from NEWS III for the four non-estuarine specialists, Ringed Plover, Sanderling, Purple Sandpiper and Turnstone were 16,203, 12,903, 10,184 and 25,988 individuals respectively. Compared to NEWS II estimates, the population point estimates for Ringed Plover, Purple Sandpiper and Turnstone decreased, although only in the case of Turnstone did the 95% confidence intervals for the two surveys not overlap. The point estimate for Sanderling increased from NEWS II.
- Further analyses of these data are planned targeting publication in peer-reviewed journals of investigations of population change and the importance of beach-cast seaweed to wader species.
