Adapted for Living in Water
The hippopotamus or hippo is well adapted for life in the water. These huge animals are found living in slow-moving rivers and lakes in Africa. With their eyes, ears, and nostrils on the top of the head, hippos can hear, see, and breathe while most of their body is underwater. Hippos also have a set of built-in goggles - a clear membrane which covers their eyes for protection while still allowing them to see underwater. Their nostrils close and they can hold their breath for five minutes or longer when underwater. Yet, in spite of all these adaptations, a hippo is not a good swimmer! Instead, it walks or runs on the river bed. Its grayish body has very thick skin which is virtually hairless. Despite their great weight, hippos can run very fast indeed.
The hippopotamus is the third-largest living land mammal, after elephants and white rhinos. There are only two types of hippopotamus in the hippo family. One is the common hippo, also known as the river hippo and the other is the much rarer pygmy hippopotamus. The river hippo can grow up to 13 feet in length, and weigh as much as a small truck - around 5000 pounds. The pygmy hippo is much smaller. River hippos spend the majority of their daylight hours in the water to keep cool. They leave the rivers and lakes at night in search of food, often having to travel great distances to find what they like to eat which is grass. They will eat other plants if no grass is available. The main threat to hippos comes from the loss of its grazing lands to development.