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BirdTrends 2013: trends in numbers, breeding success and survival for UK breeding birds
Grey Wagtail is one of the decreasing species highlighted by BirdTrends 2013 - WBS/WBBS
volunteers have recorded a 58% decline since 1975, moving it to the high-alert category


Key findings

Species list


Using the BirdTrends pages

These pages are a one-stop shop for information about the population status of the common breeding birds of the wider UK countryside. The report is based on data gathered by the many thousands of volunteers who contribute to BTO-led surveys. For each of 117 species, users can quickly access the latest information on trends in population size, breeding performance and survival rates, as measured by our long-term monitoring schemes. 

The website covers the majority of UK breeding birds but excludes (with a few exceptions) colonial seabirds, which are well covered by the JNCC's Seabird Monitoring Programme, and the rare species that are included in the reports of the Rare Breeding Birds Panel (e.g. Holling & RBBP 2012). For each species, we provide:

  • General information concerning species' conservation listings and UK population sizes
  • A summary of observed changes in the size of the population and information concerning the possible causes of these changes
  • A series of graphs and tables showing the trends and changes in population size, breeding performance and survival over the longest periods available
  • Trends for the BTO/JNCC/RSPB Breeding Bird Survey (BBS) cover not just UK as a whole but also each of its constituent countries (England, Scotland, Wales and Northern Ireland)
  • Alerts, drawing attention to population declines in any census scheme of greater than 25%, or greater than 50%, that have occurred over the past five, 10 and 25 years and the maximum period available (usually 44 years).

Text, tables, graphs and presentation are updated annually to include the latest results and interpretative material from the literature. Information on demographic trends and on the causes of change is gradually being expanded. The Key findings page provides a brief overview of our main findings this year.

Supporting pages describe the field and analytical methods that were used to produce the results for each species and to identify alerts. We discuss overall patterns of trends in abundance and breeding success, and compare the latest trend information and alerts with the Birds of Conservation Concern list (Eaton et al. 2009). Summary tables list alerts and population changes by scheme, and there is also a facility to select and display your own tables of population change. A detailed References section lists more than 640 of the most relevant recent publications, with onward links to abstracts or to full text where freely available, and is a valuable key to recent scientific work by BTO and other researchers.

We would value your comments on this report and particularly any suggestions on how it can be improved.

john.marchant [at] bto.org (Email your comments)


These web pages constitute an annual report that is part of the BTO research report series. Authors were Stephen Baillie, John Marchant, David Leech, Dario Massimino, Sarah Eglington, Alison Johnston, David Noble, Carl Barimore, Allison Kew, Iain Downie, Kate Risely and Rob Robinson. The formal citation for the report is given in the page footer.



Baillie, S.R., Marchant, J.H., Leech, D.I., Massimino, D., Eglington, S.M., Johnston, A., Noble, D.G., Barimore, C., Kew, A.J., Downie, I.S., Risely, K. & Robinson, R.A. (2014) BirdTrends 2013: trends in numbers, breeding success and survival for UK breeding birds. Research Report 652. BTO, Thetford. www.bto.org/birdtrends