It’s quite common for a female song sparrow to stray from her breeding partner and mate with the male next door, but a new study by an international group of scientists has shown that sleeping around can be costly. Song Sparrow, Melospiza melodia (Mdf) Most bird species display some form of monogamy. Bonded pairs stay together for a breeding season, a few seasons, or sometimes for life. But beneath this veneer of monogamy, there’s plenty...
