Nesting near a streetlight brightens the chances of philandering for young male birds.
Among birds called blue tits in a forest on the outskirts of Vienna, a yearling male often fathers at least one illicit chick if he nests within 50 meters of a lamppost, says Bart Kempenaers of the Max Planck Institute for Ornithology in Seewiesen, Germany.
In dark nests in the woods, though, roving females generally overlook youngsters in favor of older males, Kempenaers and his colleagues report in the Oct. 12 Current Biology.
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