Thousands of wildebeest drown every year during their annual migration in the Serengeti. Now scientists have discovered that what looks like a tragedy for the herd offers a rich source of key nutrients to creatures in the river and beyond.
People aren't just predators to cougars but "super predators" who strike fear in the cats at the top of the food chain. The big cats get so afraid of our sounds that they stop feeding on deer they've killed, an effect that cascades through their food chain.
Some whales can dive over 1000 meters below the ocean's surface. Turtles, elephant seals and dolphins also dive to great depths. But how do they avoid decompression sickness when they come back to the surface?