The average lifespan for a hippo in the wild is approximately 40 years. Hippos are herbivores that weigh from 3,000 to 9,920 pounds as adults. Wild adult hippos consume approximately 80 pounds of grass each night.
A mature hippo is roughly the same height as a 6-foot tall man, and hippo calves can weigh up to 100 pounds at birth. A hippo spends up to 16 hours each day, or 66 percent of its life, submerged in water to protect itself from the hot sun and dehydration. Hippos can't actually swim or even float, but they can fall asleep underwater safely. They have a natural reflex that causes them to bob up for air every couple of minutes.