Late-Rising Birds Become Cuckolds

You snooze, you lose paternity. That’s the message of a new study on wild birds in Germany. Males that wake up the earliest are able to sneakily mate with other birds’ partners. Males that sleep in, meanwhile, get stuck raising young that aren’t their own.

Great tits (Parus major) appear monogamous at first glance. They stick with one partner and cooperate to raise their young. But, like many other birds that scientists call “socially monogamous,” they sleep around. Great tit nests often contain eggs from more than one father.

North Dakota State University biologist Timothy Greives knew from previous studies that songbirds often use the early morning for their trysts. This could mean that males who are true early birds have a better chance of finding extra partners—and guarding their own partners from other males. Supporting this idea, a study in blue tits showed that males have greater mating success outside their home nests if they start singing earlier in the morning.

Lees meer: Discover Magazine