Garden birds – Greenfinch number show dramatic decline
Green finches are showing a dramatic decline over the last few years in urban gardens. It could be disease or it could be climate change but you may be able to help by filling you bird feeders with peanuts a Greenfinch favoured food. A recent bird trends report from the BTO reports
Greenfinch abundance fluctuated somewhat up to the mid 1990s, but there was little change in either survival or breeding performance during this period. More recent CBC/BBS data indicate population increases widely across the UK, followed by a sudden sharp fall induced by a widespread and severe outbreak of the respiratory disease trichomonosis that began in 2005. Integrated population modelling shows that changes in survival have indeed been the strongest contributor to annual population change. The BBS map of change in relative density between 1994-96 and 2007-09 indicates that increases over that period, strongest in East Anglia and in western Britain, contrasted with decreases in eastern Northern Ireland, northeastern Scotland and central southern England. The subsequent, disease-related decrease is ongoing in all parts of the UK. Productivity data are complex, with a substantial reduction in brood size and increased nest survival at the egg stage, with an overall minor decrease in the number of fledglings per breeding attempt. The trend towards earlier laying may be explained by recent climate change. There has been little change in numbers across Europe since 1980, in strong contrast to the striking changes in the UK
Leave a Reply
You must be logged in to post a comment.