Press Releases - Sept/Oct 2005 - Item 1

No. 2005/09/27
12 September 2005

Citizen Science

‘Armchair’ birdwatchers have made a valuable contribution to our understanding of what is happening to Britain’s birds, so say the authors of an important study just published in a leading scientific journal. BTO/CJ Garden BirdWatchers have been recording birds in their gardens for a decade and their efforts have led to some exciting discoveries.

‘Citizen Science’ is the term coined by Americans to describe studies where members of the public generate the data. The use of large numbers of ‘amateurs’ in this way has been dismissed by some in the past but is increasingly being seen as an excellent way to collect quality information over a large area.

10% of the UK’s land area is associated with human habitation, and private gardens form a significant part of this total. To put it in perspective, more of the UK is garden than nature reserve. This means gardens form an incredibly important habitat for birds and other wildlife. Private gardens are notoriously difficult to survey for obvious reasons. However, with the recruitment of an army of ‘citizen scientists’ the BTO’s Garden BirdWatch survey has managed to assess the importance of gardens for birds over the past decade.

Results from the BTO/CJ Garden BirdWatch survey have just been published in the Journal of Applied Ecology by scientists from the BTO and the University of Sheffield. Entitled “Trends in the use of private gardens by wild birds in Great Britain 1995–2002” the study highlights worrying declines in species of high conservation concern (e.g. House Sparrow, Song Thrush and Starling)(see Note 1). These species have also suffered serious declines in other habitats. It seems that what is happening in the wider countryside is being mirrored in our gardens.

“This study demonstrates how important the contributions made by ‘armchair’ birdwatchers are to science and conservation. For most volunteers their interest in birds doesn’t extend beyond the confines of their garden but careful observation and recording, coupled with a sufficiently precise survey technique, has provided a wealth of information for scientific analysis” says Mike Toms, Garden BirdWatch organiser.

“The BTO/CJ Garden BirdWatch study has only been possible because of the thousands of people who give up a bit of time each week to record their garden birds”, Mike adds. “We couldn’t survey garden birds as well as we do were it not for this army of volunteer birdwatchers.”

The BTO needs more people to record the occurrence of birds in their gardens. It has been running its Garden BirdWatch survey since 1995. Some 16,500 participants currently take part in Garden BirdWatch and send in simple weekly records of the bird species using their gardens. To receive a free information pack, phone on 01842 750050 or write to GBW, Room 27 British Trust for Ornithology, The Nunnery, Thetford, Norfolk IP24 2PU.

Notes for Editors

1. In 1995 House Sparrows were recorded in 83% of gardens, Song thrushes 37% and Starlings 79%. By 2002 this had declined to 72% for House Sparrows, 19% for Song thrushes and 60% for Starlings.

2. The BTO/CJ Garden BirdWatch. The BTO/CJ Garden BirdWatch is the only nationwide survey of garden birds to run weekly throughout the year, providing important information on how birds use gardens, and how this use changes over time. Currently, some 16,500 people take part in the project. The BTO/CJ Garden BirdWatch is funded by participants’ contributions and supported by CJ WildBird Foods Ltd and is the largest year round survey of garden birds anywhere in the world. For more information see www.bto.org/gbw

3. Bird Table Magazine. Bird Table magazine is published quarterly and sent free to all BTO/CJ Garden BirdWatchers. An annual subscription to the project costs just £12 and all new joiners will receive a free copy of the BTO/CJ Garden BirdWatch Book (which normally retails for £9.99). Electronic versions of the Bird Table articles are available for Editors and can be requested from

4. Colour photographs. Images of garden birds are freely available for use in association with this press release. Please contact to request an electronic version.

5. CJ WildBird Foods. CJ WildBird Foods is Europe’s leading supplier of bird food and bird feeding products. CJ WildBird Foods has been responsible for a number of significant developments within the bird food and feeding industry, including the introduction of black sunflower seeds to the UK as a major new bird food and the development of specialist seed mixes for use in tubular feeders. The company has also been supporting research into the changing fortunes of garden bird populations, most notably through the BTO/CJ Garden BirdWatch.

6. The BTO has an ISDN line available for radio interviews.

For further information please contact:

Martin Fowlie on 01842 750050 (during office hours) or email
Mike Toms on 01842 750050 (during office hours)

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