Fifty years of citizen science shows a positive response to climate change by a third of English breeding birds

02 Sep 2019 | No. 2019-25

New research, just published in the journal Bird Study, has shown that one third of 68 breeding species in England have been affected by climate change, leading to notable increases in some and declines in a few.

Looking at fifty years of data collected in England by citizen scientists as part of the British Trust for Ornithology’s (BTO) long-term monitoring of bird populations, scientists from BTO and Natural England have shown that there are real effects of climate change on bird populations in England, particularly for a range of resident species during both the summer and winter.

Of the 68 species looked at, 24 showed evidence that changes in their populations were linked to temperature or rainfall. For thirteen species (including Corn Bunting, Goldcrest and Long-tailed Tit), their populations appeared to be at least 10% larger as a result of climatic trends, whilst at least three species saw their numbers fall by at least 10% as a result of climate change - Cuckoo, Little Owl and Reed Warbler.

James Pearce-Higgins, Director of Science at the BTO and the paper’s lead author, said, “Given the changeable British weather, it can be difficult for us to see the long-term impacts of climate change, but by monitoring bird populations we can track impacts upon the natural environment. Thanks to the efforts of our volunteer bird surveyors who have been counting birds in England for over 50 years, we can show that climate change is already affecting about 1/3 of breeding bird populations monitored. Whilst some of these impacts have resulted in population increases, as harsh winters which naturally limit the populations of some resident species have become less common through time, there are also species which appear to have declined too.” 

Access the full paper.
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Notes to editors

1. The BTO is the UK's leading bird research charity. A growing membership and up to 60,000 volunteer birdwatchers contribute to the BTO's surveys, collecting information that underpins conservation action in the UK. The BTO maintains a staff of 100 at its offices in Thetford, Stirling, Bangor (Wales) and Bangor (Northern Ireland), who analyse and publicise the results of surveys and projects. The BTO's work is funded by BTO supporters, government, trusts, industry and conservation organisations. 
2. This work was funded by the BritishTrust for Ornithology and Natural England. The annual population trend estimates for England used in this study originate from the BTO Common Bird Census and more recently, from the BTO/ JNCC/RSPB Breeding Bird Survey. The latter is supported by a Partnership jointly funded by the BTO, RSPB and JNCC, with fieldwork conducted by volunteers, to whom we are very grateful.

3. The paper is published in the journal Bird Study, with the following citation: J.W. Pearce-Higgins and H.Q.P.Crick One-third of English breeding bird species show evidence of population responses to climatic variables over 50 years. DOI: 10.1080/00063657.2019.1630360 It can be accessed via this link:

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