A free meal might seem like just the thing for your bird friends in winter, especially if that meal takes place in front of your picture window. But your feeder could be harming some bird species more than it's helping them. Even if it's a squirrel-proof seed tube or a pinecone rolled in peanut butter, there's still no such thing as a free lunch.
"We are really only in the early stages of understanding exactly what effects bird feeding is having on our wild bird populations," says Kate Plummer, an ecologist at the British Trust for Ornithology. Britons love to feed the birds. The BTO says that about half of everyone in the United Kingdom does it.
To find out how extra food during the winter months might affect wild birds, Plummer and her colleagues used populations of blue tits (Cyanistes caeruleus) that had never set eyes on a bird ...
