closeup of a common hippo sleeping, semi aquatic mammal from africa, vulnerable tropical animal specie

africa african amphibius animal animals aquatic closeup common conservation exotic herbivore herbivores herbivorous hippo hippopotamidae hippopotamus hippos hoofed lake land lazy list listed mammal mammals popular portrait red resting river sahara semi sleeping specie species status swamp threatened tired tiredness tropical ungulate ungulates vulnerable water wet wetlands zoo zoology