Chaffinch Appeal

In just eleven years from 2007–2018, the UK Chaffinch population fell by a staggering 30%. This appeal helped us make the best use of BTO’s data resources and investigate the causes of the decline, enabling us to inform conservation solutions.

This appeal is now closed to donations, but you can still support our work:

Chaffinch and Greenfinch. Edmund Fellowes — Why have Chaffinch numbers only started to decrease dramatically in 2012, and not when the trichomonosis outbreak first occurred amongst Greenfinches? Edmund Fellowes

Detail in the data

Volunteer-gathered data have highlighted the developing Chaffinch population crisis. Long-term trends show not only that Chaffinch numbers are in steep decline, but also that there is disparity in the timings and rates of decrease between the individual countries in the UK. Does this mean Chaffinches are facing different pressures in different places?

Further analysis of Garden BirdWatch data could provide important insight, by revealing the population trends for smaller areas, and allowing comparisons between neighbouring cities and countryside. Exploring the different conditions between the regions could help to determine the key factors influencing not just Chaffinch populations, but also those of other UK birds.

Breeding Bird Survey trends for Chaffinch population in UK — Between 2007 and 2018, the UK population of Chaffinches fell by 30% (BTO/JNCC/RSPB Breeding Bird Survey)

I remember my grandfather showing me them in his garden when I was small, and recently I enjoyed helping my own five-year-old identify and record the Chaffinches we saw for his homework. It worries me to think that he might not see them as a common bird when he's my age. Kate Risely, Garden BirdWatch Organiser

Your Observations Matter

One potential cause of the drop in Chaffinch numbers is a disease called Trichomonosis. In partnership with ZSL, RSPB, and Froglife, we deliver the Garden Wildlife Health project, which aims to monitor the health of, and identify disease threats to, British wildlife. We have improved how we capture observations of sickness in birds in our Garden BirdWatch survey, and now are able to share these data directly with Garden Wildlife Health. We thank you, our volunteers, supporters, and the general public, for providing us with the sightings which we rely on to conduct our research. Together, we are able to build a picture of the status of bird life in the UK, and the most pressing threats, informing critical conservation action.