I received this change of advice from the BTO Ringing & Licensing team by email this morning. It was nice to see my own practices largely vindicated.
“As you may have seen this morning in the news and on social media, today sees a change in the best practice advice being given to those feeding birds, particularly in their gardens. The new advice is to halt the provision of seeds and peanuts in the warmer months of May to October, when the risk of finch Trichomonosis outbreaks is elevated. We felt that it was important that ringers should be aware of the change, the background to why this change has been made (following a review led by RSPB, with input from BTO and the Institute of Zoology), and how ringing fits into this new advice.
In acknowledgement of the significant conservation value brought by ringing activities dependent on provision of food during the breeding season, and the extremely small contribution that these make to bird feeding at a national scale, we will not be mandating that ringers cease use of peanuts and seed. We will, however, be producing targeted hygiene guidance to enable minimisation of possible risks. We ask that you make yourself aware of the seasonal feeding advice and encourage you to support it where possible, and as usual you should ensure adequate hygiene measures are in place when provisioning birds year-round.
Background
In late 2024, growing concerns about the risks of feeding wild birds prompted a review, led by RSPB, with significant input from BTO. It examined the possible pros and cons of feeding wild birds, using published science to establish what we know and what we don’t. It looked at how the provision of food influences individuals, populations and communities, through effects on survival, disease risk and competition, amongst others.
The review was overseen by a Technical Steering Group, with BTO Senior Research Ecologist Kate Plummer contributing to the evaluation and interpretation of the evidence base. RSPB has used the review to inform its approach to feeding wild birds, both in terms of its commercial sales operation and the advice that it gives to the public. BTO has also updated its advice.
What the evidence says
Feeding can support birds in various ways, and also provides valued opportunities for people to connect with nature. While the scientific evidence is limited for some aspects, the strongest and most clearly understood evidence currently relates to disease transmission at garden feeding stations, particularly of finch Trichomonosis.
Based on the review’s findings, the revised guidance recommends halting the provision of seeds and peanuts in the warmer months of May to October, when the risk of finch Trichomonosis outbreaks is elevated. Other foods, such as mealworms and fat / suet products, which are rarely used by species typically affected by Trichomonosis, may continue to be provided, although attention to spoilage remains important and it is worth noting that fat products are generally less suitable in hot weather.
Whatever the time of year, good hygiene remains essential; offering food little and often, cleaning feeders regularly, and moving them periodically to reduce build-up of waste and contamination.
The updated guidance also highlights the importance of water hygiene, since water sources can be a transmission route for the Trichomonas parasite. If a garden or a neighbour has a shallow-edged pond that allows birds to drink and bathe, there is generally no need to provide additional water unless the pond has dried out or frozen. Where water is provided, it should be replaced daily. Bowls or trays should be cleaned weekly, then rinsed and dried before reuse. Taken together, these adjustments reflect a shift towards more considered and lower-risk feeding practices, particularly during periods when disease transmission risk is elevated. By adjusting the timing and type of food provided, it is possible to reduce opportunities for Trichomonosis transmission while continuing to enjoy the benefits of feeding.” ENDS
I am pleased to say that I have always conformed to what is now represented as best practice. The supplementary feeding I carry out in my woodland sites starts when the cold weather starts end of October, beginning of November and stop mid-March as the weather warms up and natural feed starts to be more abundant. No additional water is provided in the wild sites.
In my garden I feed all year round. I do have a pond and I do provide fresh water in a small round RSPB purchased bowl, which is refilled every day and sterilised every week, using an anti-HPAI certified disinfectant. I provide peanuts, fat balls, Sunflower seeds and mealworms and I would say that my cleanliness regime is exemplary. I actually stopped using bird tables back in 2014, as more evidence was coming out about bacterial diseases being spread via feeding, and my recognising that it is impossible to keep a bird table completely free of potential contaminants. Ever since, I have only used hanging feeders for seed and peanuts. They are hanged in such a way that they are not accessible to pigeons or doves, the birds that are probably the originating source of the Trichomonosis contamination, having been recognised as a regular problem for them, documented since 1878. It is more commonly called canker in those species.
I have seen an almost complete recovery of Greenfinch in my garden, having been studying it since I moved there in December 1997. In March 2003 I joined the BTO Garden Birdwatch Scheme, reporting the weekly maxima of each species observed in my garden. Once I got my ringing C-permit, I have carried out the occasional ringing session in my garden since August 2012. I noticed the catastrophic decline in Greenfinch numbers when Trichomonosis hit in 2005, but since 2015 the numbers have steadily increased, and I haven’t seen any sign of a diseased Greenfinch in my garden for at least 6 years. Last year I had a maximum count of 10 on my feeders, during the breeding season, and five each of male and female, hopefully pairs, and subsequently have seen multiple juveniles at the feeders, and a winter flock of 20+ in the old oak tree behind my property, on the edge of agricultural land. This Spring I have had a maximum count of four pairs so far in the garden.
I have read the RSPB article referred to in the BTO introduction to this. It does look as though they are currently carrying out some studies to find out the truth about the spread of Trichomonosis. You can read their article here:
https://www.rspb.org.uk/whats-happening/news/the-science-of-bird-feeding
I was also advised by Mike Toms of the BTO that they are also involved in gathering evidence so that significant progress can be made. That is the one thing I have asked of everybody making this claim. It is the one thing that is missing: a scientific, peer-reviewed paper analysing the situation. The only thing I find slightly worrying about what is being said, is that the sampling will take place only in gardens where diseased birds have been found. To get an unbiased sample to acknowledge the scale of things, there really should be samples taken from all gardens in which feeding takes place. Perhaps that will follow on, but it will be hard to calculate the scale of the problem if it only focuses on the problem itself.
To date I have never been seen anything that is relevant to the likelihood of Trichomonosis being spread through feeding. Unlike, for example, Salmonellosis. The only paper that I found, as a result of a post made by Dr Alex Lees of Manchester Metropolitan University, was hard to see how it applied in a real world situation. All samples were incubated at 37oC, which bears no resemblance to ambient weather conditions in the UK. It is open access, in the Journal of Animal Diseases:
Trichomonas gallinae Persistence in Four Water Treatments
Kathryn E. Purple,1,2 Jacob M. Humm,3 R. Brian Kirby,3 Christina G. Saidak,3 and Richard Gerhold1,4
1.Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, 2407 River Drive, Knoxville, Tennessee 37996, USA;
2.Comparative and Experimental Medicine, College of Veterinary Medicine, University of Tennessee, 2407 River Drive, Knoxville, Tennessee 37996, USA;
3. Department of Forestry, Wildlife and Fisheries, College of Agricultural Sciences and Natural Resources, University of Tennessee, 274 Ellington Plant Sciences Building, Knoxville, Tennessee 37996, USA;
4. Corresponding author (email: rgerhold@utk.edu)
I do have some queries about the statements made. Firstly, nobody has provided an explanation on how the infection spread so fast from the south west across the whole of the UK. The same thing happened with Avian pox in Great Tit, and to a lesser degree, Blue Tit, spreading rapidly from the south east to the north and west. As far as I am aware that was not ascribed to bird feeding. In 2013 I spent a long weekend at Gibraltar Point Observatory, ringing birds, hoping for migrants. Eight years on from the outbreak the team at the Observatory did not recognise any fall in the number of Greenfinch in their area. Indeed, with a team of three of us catching and ringing birds, I actually ringed 14 and processed three retrapped Greenfinch, all healthy to look at and in their responses and biometrics. I have no idea how things progressed there with the species, but at the time it certainly hadn’t reached them.
I fully appreciate working on the precautionary principle, until causation can be substantiated, and an evidence based framework put in place. My concern, as I have blogged about before, is the correlation = causation fallacy that people like Songbird Survival used to blacken the name of the Sparrowhawk, because their population was climbing whilst songbird populations were declining. They completely ignored two things: firstly, Sparrowhawks were nearly annihilated by organo-phosphorous chemicals used on farmland and gardens in the 1960′ and 70’s and they were simply recovering from a very low base and, secondly, it was modern farming practices: hedgerow clearances, pesticide and herbicide usage, and modern gardening trends, same pesticide and herbicide stuff and “tidiness” and patios and decking and poor feeder hygiene that is the real cause of songbird decline.
My key concern is that there is a cabal of academics who are waging a war on bird feeding, using the tactics of correlation = causation and downright misrepresentation. Anybody who reads my blog and has read my most recent one on Marsh Tits in the Braydon Forest will know exactly what I am referring to. There is a huge benefit to feeding birds. On the same morning that this email arrived from the BTO, I received another email from the RSPB with the details from their Big Garden Birdwatch. The level of participation is astonishingly large. Details are here:
Keep feeding but take care!
Ringing In The Braydon Forest & Beyond 