Should we be feeding the birds?
Around half of all British households put food out for birds. The Big Garden Birdwatch may tempt nature lovers to top up bird feeders and tables to lure more birds to their gardens to count them. But there is increasing concern over feeding birds.
What’s the problem?
A growing body of scientific evidence suggests that feeding birds can spread disease, particularly among finches. The greenfinch was put on the red list in 2021 after suffering a population crash of 63% since 1993 after a severe outbreak of trichomonosis. This emerged in 2005 and rapidly became endemic in greenfinch and chaffinch populations. An estimated 6m greenfinches and chaffinches have died. Although greenfinch numbers have begun to recover recently, goldfinches have now been found dead from the disease. The disease is caused by the parasite Trichomonas gallinae and affects sociable, flocking birds in particular and is spread through infected saliva in water and seeds (although not to humans). Some garden birds, such as dunnock, appear not to be affected.
There are other potential drawbacks to excessive bird-feeding. A recent study found that feeding birds changes the local phosphorus cycle – potentially adding extra nutrients to the environment which can favour some plants over others and reduce biodiversity and damage wild habitats such as woodlands.
Does feeding birds do good as well?
One study estimates that the volume of food put out by British bird lovers could potentially support 196m garden birds – almost half the total number of wild birds in the British countryside. Supplying food in lean times can boost survivability of adults in winter and chicks in spring, and there’s no evidence wild birds become dependent on feeding. In turn, watching birds enhances human wellbeing. Spotting them and hearing their song boosts wellbeing for nine in 10 people, according to a recent poll. A scientific study found that anxiety levels decrease more if people give each species they see a “joy” rating rather than just count them.
How can we reduce the risk to birds?
The RSPB currently advises that it is best to use only hanging feeders and not flat tables. Diseases such as trichomonosis can be spread when an infected bird drops food on to a flat surface which another bird picks up. Other diseases such as salmonella can be spread through discarded, rotting seed husks too.
The RSPB this month announced it had stopped selling all flat bird feeders, such as those with open seed trays, pending an evidence review.
It is advised to clean hanging feeders regularly – at least every two or three refills – with soapy water and an animal-safe disinfectant or a weak bleach solution. Water containers should be rinsed out daily and bird baths refilled with fresh water every day.
The choice of seed mixes can reduce the risk of spreading bacteria – sunflower hearts are better than the seeds, which leave husks that rot on the ground and can spread disease. It is also wise to move feeders and monitor the birds using them – if any appear to be ill (fluffed up feathers and listlessness is an obvious sign), stop feeding for two weeks and empty all bird baths.
Should we just not feed the birds?
The naturalist Nick Acheson is among a growing number of bird lovers who does not put out food for wild birds. Instead, he ensures his (small) garden is well stocked with plants that provide food for birds. Uncut ivy offers midwinter berries, less frequently trimmed hedges can ensure rowan, hawthorn and others provide autumn berries for birds. Leaving grass long through summer and autumn can offer more seed heads for grateful goldfinches. Using no garden pesticides ensures there are insects for tits and other small birds to gather.
