Hippopotamus amphibius

Hippopotamus are large herbivores second only to elephants and rhinos in size, and are also very ferocious. Hippopotamus have hairless bodies, short and clumsy limbs, wide mouths with sharp tusks. Hippopotamus' eyes, external ears and nostrils are all exposed and protruding.

       Hippopotamus are mammals that like to live in groups, are afraid of cold, and prefer warm climates. Their skin will dry out if they are out of water for a long time, and foraging, mating, giving birth, and breastfeeding in life are all done in water.

       Hippopotamus are herbivores, but their sparse tusks are ten centimeters long. Female hippos are extremely territorially aggressive to protect their young. Hippos move in pairs or small groups, and older males often move alone. Hippos go ashore at dusk and can walk 10 kilometers to find tender grass. Hippos use their wide lips to grab and pull grass. Although hippos have three-chambered stomachs, hippos are not true ruminants. They spend 4-5 hours foraging and can eat 68kg of grass every night. They mainly feed on aquatic plants and occasionally on land crops, mainly grass. Sometimes they go to the fields to eat crops. When food is scarce, they also eat meat. On very rare occasions, hippos will also eat carrion by the water.

       Although hippos always stay in the water, they cannot swim and can only dive. When frightened, they usually hide in the water. They spend most of the day in the water. When lurking underwater, they usually expose their heads to the surface of the water to breathe once every 3 to 5 minutes, but they can stay lurking for about half an hour without surfacing to breathe. Hippos are usually quiet, but once they get angry, they often fight, and they use their sharp teeth to pierce each other's thick skin. Sometimes when they get angry in the river, they dare to overturn a small boat and bite it in two.

       Don't look at the bloated body of hippos. In fact, they run much faster on the shore than humans, and their short-distance running speed can reach 40 kilometers per hour. In Africa, hippos are the most murderous species among wild animals (even more than crocodiles). Hippos are extremely aggressive, especially when they are about to return to the water from the shore. If there are other creatures in the way, hippos will rush towards the obstacles furiously.

        Hippos mate in the water and have no fixed breeding season. The gestation period of females is 210-255 days. They give birth in the water and give birth to one baby per litter. The newborn baby weighs 40-50 kg and can walk and dive 5 minutes after birth. The mother hippo with the baby becomes very vicious. After the baby is born, the female will take good care of it, breastfeed in the water, let them move only within the visible range, and patiently teach them to dive and roll to protect them from harm. In the following months, the female often lives away from the group with its baby because the baby may be killed by the ferocious male or attacked by crocodiles. After 4-6 months, the cubs can eat grass, and the lactation period is about 1 year. Females usually raise their offspring alone for up to 18 months. Females mature at 7-9 years old, males at 9-11 years old, and their lifespan is about 30-40 years.

       Since 2006, hippos have been listed as "Vulnerable (VU)" species by the IUCN Red List, with about 125,000-150,000 hippos worldwide. In the Democratic Republic of Congo, the number of hippos has dropped dramatically due to war. At the same time, hippos are still threatened by habitat destruction and poaching due to human activities.

       In 2022, the Colombian Ministry of Environment announced the adoption of the recommendation of the National Technical Committee for Species Introductions (CTNEI) to define hippos as "invasive species" because they pose a serious threat to the ecosystem of the Magdalena River basin in Antioquia and other species such as manatees.

The hippopotamus is a semi-aquatic mammal that generally lives in areas with lush aquatic grass and reeds near rivers, lakes, and swamps, and some of them can live at altitudes up to 2,400 meters. The water must be deep enough for the hippopotamus to immerse its entire body in the water. Generally, water about 2 meters deep is preferred. During the day, hippos prefer to sleep in shallow water, or occasionally on densely packed mudflats. It is in these waters that mating and childbirth take place. When there are no shallow water areas, hippos lie in deeper water, leaving only their nostrils above the surface to breathe. Hippos come out of the water at dusk, go ashore to forage, and then go down separately along familiar trails, usually less than 1.6 kilometers, along the water bank to dense grasslands.

The hippopotamus is huge and clumsy, with its nostrils above the tip of its snout, in a straight line with the eyes and ears above. It is 2-5 meters long, including a tail about 35 centimeters long; it weighs 1,300-3,200 kilograms. But it is relatively short, with particularly short limbs, and its shoulder height is only 140-165 centimeters, less than half the height of an elephant. It has a thick head and a particularly large mouth, which is larger than the mouth of any animal on land, and can open at a 90-degree angle. The teeth in its mouth are also very large, with both incisors and canines in the shape of fangs, which are the main weapons of attack. The lower incisors do not grow upwards, but extend forward in parallel like a shovel, with a length of up to 60-70 centimeters and a weight of 2-3 kilograms. The canines are also about 75 centimeters long. The eyes, nostrils, ear shells, etc. are all born at the upper end of the face, almost on the same plane. The skin is very thick, u