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ARMCHAIR BIRDWATCHERS MAKE CITIZEN SCIENTISTS In Bird Table Issue 41, former BTO/CJ Garden BirdWatch Organiser Andrew Cannon reported on some of the findings of his PhD on the ecology of urban birds. Andrew highlighted the comings and goings of birds in 100 hectares of central Sheffield. This area, consisting mainly of Victorian terraced houses, seemed initially unpromising but Andrew has been able to establish, with incredible detail, the numbers and species of birds present in this type of habitat. Since then, Andrew and his colleagues at the University of Sheffield and here at the BTO have had the first scientific paper from Andrew’s thesis published, in the prestigious Journal of Applied Ecology. Entitled “Trends in the use of private gardens by wild birds in Great Britain 1995–2002” this paper directly uses the data collected by BTO/CJ Garden BirdWatchers over the past 10 years. It also combines these data at a national level with the more detailed case study of Andrew’s own site in Sheffield. Together, these two sets of information provide a real insight into the fortunes of garden birds over the last few years. Andrew and his co-authors showed that the use of gardens by birds is seasonal and also cyclic, and that different species vary in the timing and regularity of their use. Birds such as the Dunnock are recorded in gardens at a higher frequency in the winter months, presumably because they can eat scraps of food that have been dropped from feeders by other species at a time when that extra food is needed to get them through the winter. Great and Blue Tits show a similar pattern, although less pronounced, with winter-feeding in gardens being especially important for them. In contrast, the Song Thrush is more likely to be seen in the spring, which coincides with a greater number of snails and other invertebrates being available in our gardens for them to fuel their breeding attempts and to feed young chicks. Two larger species with very differing fortunes were Great Spotted Woodpecker and Jackdaw. The former has been making much more use of gardens in recent times which reflects an increasing use of food provided by householders. On the flip side, Jackdaw has shown a steady drop-off in the use that it makes of gardens, presumably because nest sites have become harder to find as people block up their chimney stacks and old trees are deemed unsafe and are cut down. In total, 18 species of birds including Woodpigeon and Mistle Thrush showed significant trends in their use of gardens over time, with some species increasing and others decreasing. What was especially interesting was that these trends often followed the increases and declines seen in results from the BTO/RSPB/JNCC Breeding Bird Survey, which monitors breeding populations across a range of different habitats. Also, the three species that showed the greatest declines in their garden use during this period (House Sparrow, Song Thrush and Starling) were species that are “Red-listed” as being of high conservation concern; that is, their populations have suffered serious declines in recent years. This tells us that Garden BirdWatch and the way it is constructed can give us meaningful insights into what is happening to birds over time, making it a very powerful tool for ecological research. In America, the use of data collected by members of the public has led to the coining of the term “Citizen Science”. However, given that Garden BirdWatchers often monitor their birds from an armchair, and that, after all, this is the UK, perhaps “science with a cuppa” is a more appropriate term for what we do! Whatever we call it, papers such as this one by Andrew and colleagues show how important and useful it can be. The use of large numbers of ‘amateur’ birdwatchers in this way is increasingly being seen as an excellent way to collect quality information over a large area. Not only are BTO/CJ Garden BirdWatchers providing good monitoring information for a habitat in which BTO surveys are difficult to run (people peering over fences with binoculars are usually frowned upon!), the data generated are also starting to provide high quality scientific publications. So, each and every one of you deserves a pat on the back, a big thank you – treat yourself to a cup of tea, sit in that armchair and keep recording! There’s never been a better excuse to stare out of the window. A. R. Cannon, D. E. Chamberlain, M. P. Toms, B. J. Hatchwell & K. J. Gaston.(2005) Trends in the use of private gardens by wild birds in Great Britain, 1995–2002. Journal of Applied Ecology, 42: 659–671 CLICK HERE TO VIEW THE PRESS RELEASE ASSOCIATED WITH THIS STORY. |
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