I seem to have struck a chord with last week’s column about feeding birds. It surprised me. Birding is obviously a big, big hobby and feeding birds is the easiest way to be a birder. Ah, still, ...

“You have to ask why birds would do this,” says Joe Corbo, a biologist at Washington University in St. Louis. “And one of the leading hypotheses is that the male has elaborate ornaments or colors that ...