The RSPB has withdrawn flat bird feeders from sale on its website amid warnings they could be spreading deadly diseases to finches.
The charity has said feeding birds from flat surfaces such as tables could be contributing to the spread of illnesses such as finch trichomonosis, which has been blamed for the plummeting greenfinch population.
It told customers: “We know so many of you love feeding your garden birds and some bird species really do benefit from us putting out extra food for them, especially in winter. However, there is increasing evidence that for other birds there can also be negative effects such as the spread of disease, especially among finches.
“As a precautionary measure, whilst we await the findings of the review, we have suspended all our bird tables and related products, table mix and table mix extra, window feeders and feeder guardians with trays, from sale. This is because there is evidence to suggest that some birds, particularly finches, can be more exposed to disease when fed on flat surfaces like these.”
Many scientists and bird enthusiasts have been worried about the greenfinch, which has experienced a population crash of 63% since 1993 after a severe outbreak of trichomonosis, caused by the parasite Trichomonas gallinae. The bird was put on the red list in 2021, indicating it was at risk. Researchers say transmission of infection is most likely to be through birds feeding one another with regurgitated food during the breeding season, or through food or drinking water contaminated with saliva. Chaffinch populations have also been declining.
Other bird organisations have commented on the RSPB decision. Jon Carter from the British Trust for Ornithology said: “Research demonstrates that there are both pros and cons to feeding the wild birds that visit our gardens. We understand the concerns that people may have about possible negative effects, particularly those linked to the emergence of infectious diseases such as finch trichomonosis.
“It is the evidence from this research that shapes the advice that we provide on feeding, and we will continue to update this advice as new evidence comes to light.” He added that the research on whether flat surfaces spread diseases had not yet been completed.
People can still leave food out for birds in winter as long as they frequently clean their feeders to avoid the spread of disease, Carter added. “Our current advice is to maintain regular feeder and bird bath hygiene, withdrawing feeding only if there are signs of illness. As a precaution, people might wish to avoid using flat surfaces for feeding birds.
“We will update our advice once the relevant research has been completed and the results published through peer review. The RSPB decision to remove certain types of feeder from sale is in line with a precautionary approach, and we support this decision.”
