Umbi Hippos

These animals generally live near rivers, where they spend much of their time submerged, as their skin is sensitive to sunlight. Hippos are herbivores and feed at night on vegetation along the banks of the rivers they inhabit, although there is evidence of adult males engaging in cannibalism involving young hippos.
Hippos are slow-moving on land, but they can still reach speeds of 50 km/h. They are fast in the water and display several adaptations to their predominantly aquatic lifestyle, including ears and nostrils that can close and a skin secretion that acts as sunscreen, an antiseptic and an antibacterial agent.
Hippos’ skin is highly sensitive to sunburn and, to protect themselves, they secrete a reddish substance that can be mistaken for blood from a distance.
An adult male hippo (which is almost always larger than the female) can measure 4 metres and weigh up to 3,500 kg, making it one of the largest terrestrial mammals, surpassed only by elephants and rhinoceroses.
They have an extremely powerful bite of around 810 kg, more than twice the force of a lion’s bite.
The only natural predators of hippos are lions, which hunt them in packs.

Hippos are large animals with herbivorous dentition, but they have large, self-sharpening canine teeth that they use for defence.
They cause more human deaths in Africa than lions, buffaloes, elephants and rhinoceroses combined. They are highly aggressive and territorial, and they give warning signs before attacking. They will usually stare at a person and then open their large mouths to display their teeth, although many people mistake this behaviour for a yawn.
They live in social groups of around twenty animals, consisting of females and young, and led by a male.
They can live for an average of 30 years. However, in captivity, individuals of the pygmy hippopotamus species live between 42 and 55 years, longer than they do in the wild.
Their bodies are covered by rough, grey skin, which is more than 5 cm thick in some places, and supported by very short legs. Sparse hairs are scattered across their bodies.
The hippo is an excellent swimmer. Its fat, which is lighter than water and stored beneath its thick skin, helps it float. In addition, this fat helps regulate the animal’s internal temperature while it is in the water.
Hippos were sacred to the ancient Egyptians. The goddess of fertility, Taweret, was depicted as a bipedal hippopotamus.
Hippos are social animals that live in groups of 10 to 30 individuals, although groups of more than a hundred have been observed.
These groups include several females and males, but only one alpha male.

Encounters between males belonging to the same group are often settled through a behaviour known as "gaping", a term with no direct Portuguese translation. It involves two males confronting each other in the water and opening their mouths at an angle of up to 140 degrees, allowing each to assess the other's size. This helps smaller individuals submit and avoids physical confrontations that could injure both animals.
Another curious behaviour is called "flinging", in which hippos scatter their faeces along the river’s sandy banks and along their trails leading towards grazing fields. This helps them navigate without relying on sight, allowing them to follow trails back to the water using their sense of smell, even in the absence of light.

Hippos spend most of their days in water or mud with other members of their group. The water helps keep their body temperature low and prevents their skin from drying out. Hippos frequently engage in fights with other hippos, and mating takes place in the water.
Hippos leave the water at dusk and travel inland, sometimes up to 8 km, to graze on short grass, their main food source. These large animals can consume 68 kg of grass each night.
Like almost all herbivores, they also consume various other plants, but their natural diet consists almost entirely of grass, with only minimal consumption of aquatic plants.
Hippos have occasionally (though rarely) been filmed eating carrion, usually near water. There are other reports of meat-eating, and even cannibalism and predation. A hippo’s stomach anatomy is not suited to a carnivorous diet, and meat-eating is probably the result of aberrant behaviour or nutritional stress.
The diet of hippos consists mainly of terrestrial grasses, even though they spend most of their time in the water.
Because of their size and habit of following the same routes to feed, hippos can have a significant impact on the land by keeping areas clear of vegetation and compacting the ground. Over extended periods, hippos can alter the paths of swamps and waterways.
Adult hippos normally surface to breathe every 3–5 minutes. Adult hippos can move at speeds of up to 8 km per hour in the water. Young hippos need to breathe every two to three minutes.
Breathing is an automatic process, and even when asleep, a hippo will surface to breathe without waking up. A hippo closes its nostrils when submerging.
As with fish and turtles on a coral reef, hippos sometimes visit "cleaning stations". When a hippo opens its mouth there, it signals that fish can remove parasites from inside its mouth. These parasites provide food for many fish species.