Greenfinch Welfare: Trichomonosis and Garden Bird Feeding

Greenfinch populations have crashed by over 60% due to trichomonosis outbreaks spread through contaminated garden feeding stations, creating a direct welfare dilemma between bird feeding and disease transmission.

Key Facts

UK greenfinch population declined by 65% between 2006 and 2022 following trichomonosis emergence
Trichomonas gallinae causes lesions in the throat and oesophagus, preventing swallowing and causing death from starvation
The parasite spreads between birds at shared feeding stations and water sources
Proper hygiene at garden feeding stations significantly reduces disease transmission risk

Welfare Considerations

Greenfinch welfare has been severely damaged by the emergence of trichomonosis linked to garden bird feeding. Affected birds show the characteristic puffed-up, lethargic appearance of disease and die slowly from starvation. Garden feeding stations — intended as welfare-positive interventions — have become disease amplification sites when hygiene is neglected. Regular cleaning of feeders (minimum weekly with dilute disinfectant) and water bowls, use of multiple feeding stations spread over a garden, and removing feeders for a week if sick birds are seen are the critical welfare interventions. The greenfinch decline represents a sobering lesson in the welfare consequences of unintended disease transmission through feeding.

What You Can Do

Clean garden feeders and water bowls weekly with dilute disinfectant and rinse thoroughly
Spread feeding stations across the garden rather than concentrating birds at single stations
Remove feeders for one to two weeks if sick greenfinches or other birds are seen nearby
Report sick garden birds to Garden Wildlife Health to contribute to disease monitoring