A female kiwi, roughly the size of a chicken, lays an egg that can reach about 20% of her body weight, one of the largest eggs relative to the mother's size of any bird. Just before laying, it takes up so much room inside her that she struggles to eat. On a human scale, that would be like giving birth to a baby weighing more than ten kilos.
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.