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Throwing handfuls of bread to birds has long been seen as harmless enough. But in recent years, some scientists have suggested that bread might not do birds' digestive systems any good, saying that as uneaten food rots down, the water quality worsens and algal blooms can occur. Plus, by encouraging birds to gather in one place, the build-up of droppings may result in outbreaks of disease too. Meanwhile, many cities have signs telling us not to feed pigeons and gulls, which are considered an "annoyance" due to the mess they make, and scattering bread inevitably attracts rats and mice.
It seems that the public has accepted these warnings, and that fewer of us now feed birds this way. In October, a sign went up in a Derbyshire park claiming that the local birds were dying of starvation, and urging visitors to feed them as before. When online posts about the notice went viral, feathers flew as people debated the benefits of handing out bread to birds.
Paul Stancliffe of the British Trust for Ornithology(BTO) points out that there's insufficient scientific evidence for bread harming birds, adding that, as little research has been done, it could even turn out to be beneficial.①"We just don't know," he says. Although bread is a heavily processed "unnatural" food intended for humans, that alone may be insufficient grounds for not feeding it to birds.
In the 1980s, the Wildfowl & Wetland Trust (WWT) carried out a comparative study of different flocks of mute swans, and the birds that consumed the most bread had weaker muscles, implying that a bread-heavy diet might be the cause. "Our official line is that bread is okay for ducks, geese and swans, but only in moderation," says WWT's Peter Morris. "However, this advice comes with several other warnings. "②The first is that it's best offered in winter, when there is less plant and insect food around. In spring and summer, too much artificial food may not be a good idea, since young birds have to learn how to look after themselves and natural food will contain a wider range of nutrients to help them grow.
"Just like us, birds need a varied diet to stay healthy," says a spokesperson for the Royal Society for the Protection of Birds(RSPB). "Although ducks, geese and swans can digest all types of bread, too much can leave them feeling full without giving them all of the important vitamins, minerals and nutrients they need. "③
When bird feeding first became popular in the UK in the 19th century, some Victorians encouraged tough love, arguing that such handouts would only make our feathered friends lazy and dependent on welfare.④Morris says that there is a theory that wild birds can get "hooked" on easy meals, losing interest in other types of food. Another danger, he says, is that birds fed regularly end up accustomed to humans, placing themselves at greater risk of predation(捕食).