Want to help garden birds? Don’t feed them in warmer months, says RSPB

The UK’s leading bird conservation organization, the Royal Society for the Protection of Birds (RSPB), is urging gardeners to pause feeding birds from mid-May to the end of October to curb the spread of illness. While many believe providing food is a thoughtful act, this practice might inadvertently harm certain species, according to the charity.

Trichomonosis: A Growing Threat

Warmer seasons can transform well-used feeders into disease breeding grounds. The parasite responsible for trichomonosis, which affects birds’ mouth, throat, and upper digestive systems, has led to sharp declines in populations like greenfinches and chaffinches. These birds, once common in UK gardens, have seen a drop of two million since the 1970s. Now listed as endangered, their numbers have fallen to the 18th position in the latest Big Garden Birdwatch survey, down from seventh in 1979.

How the Disease Spreads

Trichomonosis is transmitted when infected birds release the parasite through saliva and droppings, contaminating food supplies. It can also spread to young birds when adults regurgitate food. The RSPB highlights that contaminated debris on the ground poses a risk, especially on flat surfaces where buildup occurs. To address this, the charity stopped selling flat feeders last year and advises against using traditional bird tables.

Millions of households regularly provide bird food, with estimates suggesting one feeder for every nine birds. Annual spending on bird food reaches £380 million, equivalent to over 150,000 tonnes—enough to support three times the breeding populations of the most common garden birds if used year-round.

Adapting Feeding Habits

The RSPB promotes “feed seasonally, feed safely” as its new guideline. While a single infected bird can turn feeders into disease hotspots, small amounts of mealworms, fat balls, and suet—limited to a couple of days—are still acceptable. The charity recommends weekly cleaning of feeders and relocating them after each session to minimize contamination. Fresh tap water should be used daily for bird baths, and they should be cleaned regularly.

“It’s really nice to see them from the window— they look very chipper out there,” says Helen Rowe, a London resident who feeds sparrows. She plans to follow the RSPB’s advice, even though she misses the close interactions with the birds.

Some argue the advice may not apply equally everywhere. Dick Woods, a manufacturer of easy-to-clean feeders, notes that natural food availability varies greatly. “In some gardens, food is so abundant that birds don’t rely on feeders; in others, there’s little alternative,” he explains. The RSPB acknowledges these differences but insists a clear message is more impactful for widespread adoption.

“We are well aware that things won’t change overnight and that behavior change will take years, if not decades. We have therefore sought to keep our advice as simple as possible to make it easier for people to follow,” says Martin Fowlie of the RSPB.

The pet food industry has expressed concerns, calling the guidance a “significant change to long-established advice.” They warn it might confuse the millions of people who depend on feeding birds for enjoyment and connection with nature. Despite this, the RSPB remains focused on reducing disease risks through seasonal feeding practices.