It's doing more harm than good

Birdwatch Ireland have issued a fresh warning to bird lovers, saying that the practice of leaving food out for them can do more harm than good.

This is because the organisation says feeding the birds can aid the spread of trichomoniasis, and therefore lead to a negative impact on populations.

Bird feeders can spread the disease via saliva, and the shared feeders can make it spread more broadly in populations.

Therefore, it is advised that households do not feed birds between May and October.

Niall Hatch of Birdwatch Ireland spoke on RTÉ's Morning Ireland to share the news.

"Up until now people have always been doing things right. Birdwatch Ireland's advice has always been that feeding birds year-round is okay," he told the show.

"But we are changing that now because of this disease trichomoniasis…which affects finches in particular.

"We know that garden feeders now are a vector for this, particularly during the warmer months of the year, which allows this disease to survive and thrive and pass the infection on.

"It gets to the point where we are seeing between May and October feeding birds in the garden is thought to do more harm than good."

Populations of greenfinches and chaffinches have "plummeted" in many areas of Ireland due to trichomoniasis, Hatch said.

What is trichomoniasis?

Trichomoniasis is a disease that causes a swelling in the throats of birds, meaning that they cannot swallow and then they starve. There is no cure for birds who have trichomoniasis.

Hatch told RTÉ that there is no threat to humans from trichomoniasis.

The birds that are infected shed the parasite in their saliva and poo, contaminating food sources when they feed. And when adults regurgitate food, it can also be passed directly to chicks.

"This is a bird disease; it is no threat to humans or indeed any mammals.

"None of us can catch this, it is for birds and is not related to bird flu, it is a completely separate disease," he said.

What else do I need to know?

British association RSPB says that water should only be provided if it can be changed daily, and only fresh tap water should be used, while bird baths should also be cleaned every week.

According to the charity, research suggests the risk of disease transmission is higher on flat surfaces, where contamination can accumulate.

Meanwhile, the pet food industry has pushed back against the changes, describing the new guidance as “a significant change to long-established advice", and has warned it risks "confusing the millions of people who regularly feed birds”.

“The evidence informing these changes is still evolving, and much of the research underpinning this has not yet been published or widely scrutinized”, chief executive of UK Pet Food, Michael Bellingham said.

According to the RSPB, the new guidance was developed with scientists from the British Trust for Ornithology and the Institute of Zoology, and is based on what it describes as a “thorough and robust” review of the evidence. It says the full report will be published online.

The charity said that “we cannot continue as usual”, while it admitted that the change presents a challenge for the bird food industry.