BirdTrends 2014: trends in numbers, breeding success and survival for UK breeding birds

House Martins. Photograph by Liz Cutting

House Martin, now with a statistically significant long-term decline of 69%, is the subject of
special BTO surveys in 2015-16.

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 120 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. 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
  • Wherever possible, trends 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 45 years).

Text, tables, graphs and presentation for each species 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. There are new pages this year for Gadwall, Little Egret and Common Tern.

There is far more to this report besides the species pages! 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 700 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.The Key findings page provides a brief overview of our main findings this year.

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

john.marchant [at] (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, Carl Barimore, Daria Dadam, Sarah Harris, Allison Kew, Iain Downie, David Noble, Kate Risely and Rob Robinson. The recommended citation for the report is as follows, and is given in the page footer throughout the report:

Baillie, S.R., Marchant, J.H., Leech, D.I., Massimino, D., Sullivan, M.J.P., Eglington, S.M., Barimore, C., Dadam, D., Downie, I.S., Harris, S.J., Kew, A.J., Newson, S.E., Noble, D.G., Risely, K. & Robinson, R.A. (2014) BirdTrends 2014: trends in numbers, breeding success and survival for UK breeding birds. Research Report 662. BTO, Thetford.