RSPB pulls bird tables from online stores due to concerns about the spread of disease.
The RSPB (Royal Society for the Protection of Birds) in the UK has removed flat bird feeders from its online store as part of an ongoing review, due to ‘increasing evidence’ that these could be contributing to the spread of disease, particularly among finches.
‘As a precautionary measure, whilst we await the findings of the review, we have suspended all our bird tables and related products…. 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.’
Trichomonosis is the disease causing the biggest concern. The 2021 UK Breeding Bird Survey (BBS) found that the greenfinch population in the UK had declined significantly since the mid-2000s, amounting to an overall decline of 77% according to The Dirt. As a result, the Greenfinch has now been red-listed on the Birds of Conservation Concern. Chaffinch populations have also been negatively affected, although less severely.
Does this transfer to North American species?
Whilst Trichomonosis is primarily an issue in the UK and continental Europe, as we reported back in September of last year, the outbreak of salmonellosis in some US states and southwestern Canada prompted multiple wildlife departments to issue recommendations to take down feeders (of any sort) whilst the outbreak was ongoing. This disease affects Pine Siskins and goldfinches in particular.
In regions that experience distinct seasons, the spread of such diseases can be particularly common in winter and springtime as more birds gather to feed. Ultimately, the spread of disease in bird populations will always be more likely to occur around feeders, due to the repeated congregation of animals around a specific location, plus the regular gathering of different species together that normally would not mingle in the wild, potentially leading to new cross-species strains. However, this does not mean that you should tear down all your feeders! As we’ll discuss below, with proper cleaning you can minimize the risk and still help your local bird population with feeders.
Why are flat bird feeders in particular under scrutiny?
Although the RSPB didn’t go into detail about why flat feeders, in particular, are being removed, nor did they quote the specific research they’re referring to, their reasoning is fairly sound based on what we do know about disease transmission among birds.
As reported by The Dirt, Dick Woods of Finches Friend says that the key things to think about are the three ‘F’s:
“Food, Feet and Faeces. Disease transmission is to a great extent down to regurgitation, faeces and damp. Choose feeders that keep the food dry and limits access by birds to a perch. People simply do not understand that a single sick bird, through its saliva can create a chain reaction within their feeders, damp food becomes a host for the trichomonosis causing parasite, which can present at other ports on side port feeders as the food drops. Husks stick to sick birds beaks and are then left around ports or dropped to the ground, in both scenarios they are infectious.”
Flat bird feeders are particularly susceptible to amplifying the above risk factors as food and feces do not tend to fall to the ground below but stay decomposing on the surface. Additionally, the flat surface does not discriminate between bird species, increasing the risk of transmission of trichomonosis from pigeons/doves (from where it is thought to originate) to susceptible finches – this is just one example of inter-species transmission, there are many others.
What can we do to reduce the spread of disease from bird feeders & bird baths?
Despite all the worrying data discussed above, bird feeders are still thought to be a worthwhile way of helping bird populations in the colder months of the year – you just have to take some precautions.
Rotating the location of your feeder(s) on a weekly basis will help to minimize the amount of disease-transmitting droppings and food waste in any one area.
You should also try and clean any bird baths and bird feeders on a weekly basis (though cleaning them more frequently certainly will not be a problem), completely removing any spilled feed and bird droppings. Dan Grear of the USGS National Wildlife Health Center recommends cleaning with a 10% household bleach solution (9 parts water: 1 part bleach), but you obviously want to be very careful you don’t make the mixture too strong.
There’s a bit of debate about what is the ‘right feeder’ but definitely avoid flat-table designs as the RSPB is doing. Smaller-sized feeders will reduce the amount of birds congregating around any one spot, and discourage larger birds like pigeons and doves from landing on those meant for finches, for instance.
