Hippos, or hippopotamuses, are large, semi-aquatic mammals native to sub-Saharan Africa. 

Physical Characteristics: Hippos are among the largest land mammals, with adult males, called bulls, weighing between 1,500 to 3,200 kilograms (3,300 to 7,000 pounds), while females, called cows, are slightly smaller. They have a bulky, barrel-shaped body with short legs, a broad head, and a large mouth. Their skin is thick and hairless, and it secretes a pinkish-red oily substance that helps protect against sunburn and keeps their skin moist. Hippos have large tusks, which are elongated canine teeth that can grow up to 50 centimetres (20 inches) long.

Habitat: Hippos inhabit rivers, lakes, and swamps in sub-Saharan Africa, where they spend much of their time submerged in water to stay cool and avoid sunburn. They are primarily found in freshwater habitats with ample vegetation for grazing and access to deeper water for swimming and breeding. Hippos are most commonly found in the rivers and lakes of East Africa, particularly in countries such as Kenya, Tanzania, Zambia, and Uganda.

Diet: Hippos are herbivores and primarily feed on grasses, aquatic plants, and other vegetation. They are grazers and spend several hours each night feeding on grasses along riverbanks and in shallow water. Despite their large size, hippos have specialized stomachs adapted for digesting tough, fibrous plant material, and they can consume large quantities of food in a single feeding session.

Behaviour: Hippos are primarily nocturnal, meaning they are most active at night. During the day, they typically rest and sleep in the water to stay cool and avoid the heat of the sun. Hippos are highly territorial and aggressive animals, particularly males, which defend their territories and females from intruders. They communicate with each other through vocalizations such as grunts, roars, and bellows, as well as through body language such as yawning, posturing, and scent marking.

Reproduction: Breeding in hippos can occur throughout the year, although peak breeding activity often occurs during the rainy season when water levels are higher. Females give birth to single calves after a gestation period of around 8 months. Calves are born underwater and are capable of swimming and following their mother shortly after birth. They are cared for and protected by their mother for several months before becoming more independent.

Conservation Status: Hippos are listed as Vulnerable on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species, with populations declining due to habitat loss, habitat degradation, poaching, and human-wildlife conflict. Conservation efforts focus on protecting their remaining habitats, managing human-hippo interactions, enforcing anti-poaching laws, and promoting sustainable land use practices.

Overall, hippos are fascinating and iconic animals with a rich cultural history and important ecological role as herbivores and ecosystem engineers in African freshwater habitats. Despite their size and formidable appearance, they are also vulnerable to human-induced threats and require conservation action to ensure their survival for future generations.