The hippopotamus (hippopotamos, hippos meaning horse and potamos meaning river), is a large, mostly plant-eating African mammal. Hippopotamus also sometimes called hippos, are gregarious, living in groups of up to 40 animals, called a pod, herd, school or bloat. A male hippopotamus is known as bull, a female as cow, and a baby as calf. A hippos lifespan is typically 40 to 50 years. Female hippos reach sexual maturity at 5 to 6 years and have a gestation period of 8 months. Donna the Hippo, 55, is the oldest known hippo in captivity. She lives at the Mesker Park Zoo in Evansville, Indiana. Hippos average 3.5 meters (11 ft) long, 1.5 meters (5 ft) tall at the shoulder, and weigh from 1,500 to 3,200 kilograms (3,300 to 7,000 lb). The Hippopotamus is a free screensaver created by RateMyScreensaver.com containing 15 high quality photographs. Screensaver Picture Count: 15 Screensaver Type: Slideshow Credit: All images in this screensaver fall under one of the following licenses: Creative Commons, Attribution ShareAlike 2.0, public domain, GNU Free Documentation License