In Photos: Hippopotamuses A gallery celebrating the fascinating African mammal that is the hippopotamus. of 7 Passenger A cormorant perches on a hippo's back. Hippos spend the majority of their time submerged in water, only coming onto land at night to graze. Squeaky A mother hippo nurtures its squealing baby hippo. Hippo vocalisations are incredibly complex, with some out of audible range. Swimmer? A fully submerged hippo. Hippos tend not to swim, but actually dive to the bottom and punt along. Vegetarian A hippo is uncharacteristically caught grazing in the sunshine. Hippos produce a natural sunblock out of their skin in order to protect their bare skin from the African sun. Crocodile? A submerged hippo leaves its raised nostrils protruding above water to breathe. Hungry Hungry Hippo A hungry hippo wades through a marsh of floating vegetation with its mouth open - exposing formidable tusks. Lounging A baby hippo and it's mother laze the day away in the water. The size difference is start, but the mother's rich milk will help the baby to grow incredibly quickly. Slideshow Pause Show Images Hide Images Tweet