Parrotfish graze algae off coral reefs by scraping the limestone with their beak-like teeth. They grind the fragments in their throat, digest the algae and excrete the rest as fine sand. A single large fish can produce hundreds of kilograms of it a year. Next time you stroll along a coral beach, you may be walking on parrotfish poop.
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.