Blog by Dr Mark Eaton, Principal Conservation Scientist, RSPB Centre for Conservation Science

Added to the Oxford English Dictionary in 2014, ‘citizen science’ (noun) is defined as “the collection and analysis of data relating to the natural world by members of the general public, typically as part of a collaborative project with professional scientists.” Increasingly recognised as a smart way to conduct research – engaging and empowering the public whilst collaborating with them to conduct robust and valuable science often beyond the reach of more traditional, professional scientist-based research – citizen science has become a bit of a buzz phrase in recent years, scattered liberally amongst research papers and funding applications by scientists attempting to capture the zeitgeist. But, to be honest, us ornithologists have been doing it for many decades – long before we knew what to call it – and dare I say it, we can claim to lead the field in the terms of robust citizen science thanks to the support of the UK’s huge numbers of keen and knowledgeable birdwatchers.

The new Breeding Bird Survey report, published today (2nd May), is one of the best examples you can find, anywhere in the world, of citizen science in action. This report is produced from the efforts of thousands of people across the UK. This includes the partnership of the British Trust for Ornithology (BTO), Joint Nature Conservation Committee (JNCC) and the RSPB, that funds and steers the Breeding Bird Survey (BBS); the BTO scientists who run the survey, analyse the data and produce the report on behalf of the partnership; the volunteers in the BTO’s network of regional coordinators who recruit, train and manage volunteer surveys; and then those surveyors themselves.

In 2018 a total of 2,738 dedicated and skilled observers gave their time freely to survey 4,022 1-km squares scattered randomly across the UK’s landscape. This is a new record, and the first time the scheme has topped the 4,000 square mark – an outstanding achievement. Not only that, but nearly all of those observers record mammals on their way around their square, and over the last ten years additional visits have been made to count butterflies on 833 of the same squares. These butterfly counts feed into the Wider Countryside Butterfly Survey, run by Butterfly Conservation – more information about this can be found here.


Photo: The Breeding Bird Survey 2018 report

Using the data for conservation

Thanks to the efforts of these volunteers, the BBS is one of the best wildlife monitoring schemes in the world, delivering scientifically robust trends in the populations of the UK’s common and widespread breeding birds every year. These trends are a vital measure of the state of breeding birds across the UK, and furthermore are an important indicator of the wider health of our environment.

BBS trends, showing how our bird populations have fared since 1994 (and, when combined with data from the predecessor survey the Common Birds Census, since the late 1960s), are used to identify the species most needing conservation help: they are a crucial component of the Birds of Conservation Concern assessments which identify the red list, of species of greatest conservation concern.

BBS data then helps inform research into the declines of red-listed species, pin-pointing the causes of declines and identifying conservation remedies. Finally, if such conservation solutions can be designed and applied, we hope future BBS trends will allow us to track the recovery of species in response to our conservation efforts.

What does this year’s report show?

The Breeding Bird Survey 2018 report gives population trends for 117 species in the UK, plus, where data is sufficient, for the UK’s four constituent countries, and for English regions.

Many of the changes detected since the beginning of the BBS in 1994 are by now familiar stories: the continued decline of farmland birds such as corn buntings and grey partridges, the struggles of a wide suite of songbirds which migrate to spend the winter south of the Sahara, including wood warblers, pied flycatchers and turtle doves, and the rise of introduced species such as mandarin ducks and ring-necked parakeets. It is the trends over longer periods, of years and decades, that are of the greatest value to us as conservationists. But sometimes the eye can be caught by the annual fluctuations, the between-year wobbles in years often caused by weather events.

A bite from the beast

This new BBS report shows the impact of one such ‘event’ – the infamous ‘Beast from the East’ which swept into the country in late February and early March 2018, with fierce winds and heavy dumps of snow – drifting chest-deep (and I’m tall!) on the slopes behind my Northumberland house, for example. While the kids were enjoying the sledging, and I like many others was enjoying watching the hordes of birds flocking to the feeders in my garden, times were tough in the bird world, particularly for small-bodied birds that feed on invertebrates. Sadly, the new BBS figures suggests that many of these birds perished in the harsh conditions: between the springs of 2017 and 2018 numbers of robins dropped by 15%, wrens by 21%, long-tailed tits by 22% and the smallest of them all, the goldcrest, by 38%. Kingfishers are also susceptible to harsh weather if it causes water bodies to freeze over for too long: their numbers fell by 38% in 2018.

Photo: Kingfisher appears to have been aff ected by cold weather events in 2018; the species suffered a year-on-year decline of 38%. Photo by Ben Andrew (

The good news is that most of these species can bounce back rapidly from such setbacks – just one or two good breeding seasons is enough for such birds to replenish populations, and it is to be hoped that the good weather through most of the 2018 spring and summer will have provided that opportunity. It is the changing climate, not passing weather events, that will have a huge impact on our bird populations over the coming decades, although of course we have to be mindful of the increasing likelihood of severe weather events, from storms and freezes to heatwaves and droughts, as a result of climate change.

Thank you to thousands of dedicated volunteers

BBS involves around 2,700 participants (or ‘citizen scientists’, if we’re being trendy) who survey more than 4,000 sites across the UK. We would like to thank all surveyors for their skill and commitment - the BBS would not be the success that it is today without them. If you fancy helping, by surveying a BBS square on two mornings every year, then find out more here.

The full BBS report can be found at this link.

For more information follow @RSPBScience and @_BTO  @BBS_birds  #BBSReport