Days Are Getting Longer for Birds

Artificial light has brought the world an unintended consequence: more birdsong. The problem is that it's not necessarily a good thing.

• A new study in Science suggests that non-natural lighting at night is causing birds to sing for nearly an hour longer each day. They start earlier in the morning and sing later in the evening.
• Researchers analyzed over 4 million birdcall recordings from across the globe made by birdwatchers via the Birdweather app, per NPR.

• "The day is effectively longer for these birds," Neil Gilbert, an Oklahoma State University ecologist who co-wrote the study, tells the Washington Post. On average, birds are singing 50 minutes longer. The number varies depending on how much artificial light they are exposed to at night, and by the particular characteristics of the birds.
• Species with larger eyes, open nests, and migratory habits—including American robins, northern cardinals, northern mockingbirds, Eurasian blackbirds, and killdeers—were most affected.
• Scientists say the fake light might be messing up the birds' sleep and hormonal cycles. On the other hand, the additional light might give them more time to forage food for their chicks, says another study author, Brent Pease of Southern Illinois University. Further research into the fast-accumulating data might better explain how they are being affected.