By fitting frigatebirds with brain-activity sensors, researchers confirmed that these seabirds sleep while flying during weeks-long trips over the ocean. They nap in bursts of about ten seconds, often with only one brain hemisphere at a time, keeping the corresponding eye open. In total they sleep around 42 minutes a day in the air, versus more than 12 hours on land.
In 2022, a young tagged bar-tailed godwit flew from Alaska to Tasmania in about 11 days of nonstop flight, covering 13,560 km without eating, drinking or landing. Before departure, these birds pile on huge fat reserves and shrink their digestive organs, which are useless during the journey.
To escape rivals, a dung beetle rolls its ball of dung in a straight line. At night, it holds its course using the glowing band of the Milky Way. In a planetarium, researchers showed that beetles rolled straight under a starry sky but wandered aimlessly when the galaxy was switched off. It was the first animal known to navigate this way.