London - Leaving food in the garden for birds during the winter may be doing more harm than good.

While Britons distribute up to 60 000 tons of bird feed a year, a study warns they may be killing some breeds with kindness.

Researchers found leaving out fat balls for blue tits resulted in reduced breeding success in the spring.

The wild birds went on to produce smaller broods compared to blue tit colonies that had not been given any additional food. Chicks in the study, published in the journal Scientific Reports, weighed less and had lower survival rates.

This could eventually lead to the overall population shrinking.

Lead author Dr Kate Plummer, of Exeter University, said: “One possibility is that winter feeding may help birds in relatively poor condition to survive and breed…But more research is needed to understand whether winter feeding is contributing to an overall change in the size of bird populations.”

However, researchers advise homeowners to continue to leave out food, as other types of birds will have come to rely on it. They suggest feeding all year round may be a better solution. - Daily Mail