Populations of birds such as goldfinches that were rarely seen in gardens 40 years ago are now booming because people are leaving out food for them, according to a new study. 

As a result they are "reshaping" entire communities, researchers said.   

In the 1970's households mainly put out nuts, oats and seed mixes. At the time, half of all birds using feeders were either sparrows and starlings.

sparrows feeding

Now there’s much more choice, with fat balls, niger seeds, suet cake and sunflower hearts all on sale. As a result there is a greater diversity of birds coming into our gardens, including long-tailed tits, siskins, nuthatches and bullfinches.

However sparrowhawk, magpie, pheasant and carrion crow numbers have also increased as they predate on birds that feed from bird feeders.

A few species like song thrush and mistle thrush who rarely come to feeders have seen numbers decline.

“We now know that garden bird feeding is one of many important environmental factors affecting British bird numbers," Dr Kate Plummer from the British Trust of Orthonology (BTO) said. “Regular visits to garden feeders in urban areas appear to have led to population growth across more than 30 different bird species, while there has been no change in the average population sizes of birds that don’t visit feeders."

Annually, British bird-lovers put out enough food to sustain up to 196 million birds at a cost of £300m a year, according to the study published in Nature Communications journal. 

“The study underlines that the pleasure we take in feeding the birds visiting our gardens can have a significant effect on our garden wildlife, and that is certainly food for thought," Dr Plummer said. 

People who put out food for birds should make sure the feeding stations are clean to avoid disease spreading, researchers warn. 

Read the full article in The Independent here

Read the full study published in Nature Communications journal

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