‘Unprecedented’ threat to garden birds
14 September 2010
Some of the UK’s best-loved garden birds are under threat from a disease sweeping through breeding populations, in some areas killing over one in three greenfinches in a single year.
A report drawing on data from the Garden Bird Health Initiative, an annual survey carried out by members of the public, and post-mortems on garden birds found about 35% of greenfinches and 20% of chaffinches died out within a year after trichomonosis jumped the ‘species barrier’ from pigeons to finches in 2005. About 500,000 birds of all species were killed by the disease in 2007.
The British Trust for Ornithology, which co-authored the report, described the epidemic as ‘unprecedented’. The disease, carried by the parasite Trichomonas gallinae, is thought to be transferred from bird to bird in saliva, through regurgitated food during the breeding season and via contaminated birdbaths and feeders. The worst outbreaks occur in late summer into autumn, with affected birds looking ‘fluffed up’, lethargic and damp around the beak.
‘This citizen science project highlights the valuable role that volunteers can play in helping us learn more about wildlife diseases, even by just watching birds in their gardens for a couple of hours each week,’ said wildlife vet and report co-author Becki Lawson.
Researchers are urging gardeners to clean bird feeders and bird baths at least once a week to avoid spreading the parasite.
Gardeners who find sick or dead garden birds can help monitor the spread and intensity of trichonomosis outbreaks by reporting the finding to the Garden Bird Health Initiative.
Download the Garden Bird Health Initiative questionnaire
Wildlife in gardens
Helping wildlife through winter