Disease threat to UK garden birds

By Victoria Gill Science reporter, BBC News
18 August 2010 A disease that first emerged in the UK in 2005 has caused a severe decline in the number of greenfinches and chaffinches, according to researchers. In the worst affected areas, greenfinch populations have fallen by an estimated 35% and in 2007 about 500,000 birds of all species were killed, they say. The British Trust for Ornithology (BTO) has blamed a fatal infection caused by the parasite Trichomonas gallinae. It said the number of deaths from such an emerging disease was unprecedented. Findings about the “disease” are reported in the journal PLoS One. The impact on birds has been estimated from a “citizen science” project in which more than 700 people have been monitoring bird numbers in their gardens since 2003. The “Garden Bird Health Initiative” involved scientists from the BTO and other conservation organisations analysing population trends of several common garden birds. Mike Toms, who is from the BTO and a co-author of the study, told BBC News: “It’s really the first time we’ve seen this level of mortality from a new and emerging disease within birds in Britain.” …