If you want to upset a rival, try whispering. That's a piece of advice that seems to work for dark-eyed juncos, a small, grayish sparrow common in North American forests. Males of this species are more likely to tick off other males when they chirp a soft, complex song than when they blast a loud, territorial song, according to research published this month in The American Naturalist. Males that heard a recording of the quiet song actively searched for the offending male, an encounter that could lead to a fight in the wild, especially during breeding season. Males that heard the loud song, meanwhile, often ignored it. Whispered songs are usually meant for females during courtship, the researchers say, so when another male hears it, he thinks someone is trying to steal his mate right from under his beak.
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