A reef is built by polyps, tiny animals related to jellyfish. Living inside their tissues are microscopic algae that provide, through photosynthesis, most of their energy, up to 90% in some species, as well as their colors. When the water gets too hot, this alliance breaks down: the coral expels its algae, turns white and risks starving.
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.