Male songbirds who sleep in later than their earlier-rising counterparts are at a higher risk of losing their mate.

In a study conducted by Timothy Greives of the University of North Dakota in Fargo, melatonin-releasing devices were attached to male birds. Melatonin is a sleep hormone which induces the circadian cycle.

The birds who were given the hormone awoke an average of ten minutes later than those those who did not receive it, and their nests contained more offspring fathered by other males. This is because for birds, mating outside of a partnership usually happens at or before sunrise, suggesting that female songbirds won't wait around to find a new partner.

Cover image: The Telegraph