On unstable pack ice, every day counts. A hooded seal mother produces milk that is about 60% fat, among the richest of any animal, compared with roughly 4% for cow's milk. In just four days, the shortest nursing period known in any mammal, her pup roughly doubles its weight. Then she leaves.
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.