The Common hippo is a very large mammal, which weighs as much as 3 tons. This huge animal is the larger of only 2 Hippo species in the world. It's mentioned in early Egyptian writings, where Hippo is portrayed as a symbol of strength and fertility. They were particularly revered in the Egyptian culture for being very protective parents.
The original range of this species used to cover sub-Saharan Africa. The small current range of Common Hippos includes East African countries such as Tanzania, Zambia and Mozambique. As semi-aquatic creatures, they prefer living in shallow water bodies such as lakes, rivers or swamps. A depth of about 2 meters will be perfect for this animal to submerge the whole body in the water.
Common hippos are highly social, nocturnal and sedentary animals. They usually form groups of 20 - 100 individuals that are led by females, who occupy the core areas of their resting pools. Males of the group are responsible for protecting females and young. Hence, they remain in the outer banks of these resting pools. The daytime hours are typically spent resting. At dusk, the animals come out of their shelters to forage. Common hippos are normally non-territorial, except when in the water. Males of this species can occasionally be observed fighting for access to females or space in the resting pool. Males and females of a group don't tend to socialize with each other and generally remain separated. Females and their offspring gather in smaller sub-groups and occasionally practice communal care, helping rear each other's claves. Communication between community members occurs through a wide range of vocalizations.
Common hippos exhibit a polygynous mating system, where one male mates with a group of females. These mammals don't have a specific breeding season, although they generally mate from February to August. Females of this species give birth underwater. They produce offspring from October to April, which coincides with the rainy season. A single baby is born after 240 days of gestation. Mothers and their young live in close bonds with each other. They display affection by activities such as cleaning and cuddling. Complete weaning occurs at about 1.5 years old, although the baby often continues living with its mother until 7 - 8 years of age, when totally independent. The age of reproductive maturity is 7 - 9 years old for males and 8 - 10 years old for females.
There two main threats to the Common hippo today: hunting and loss of its habitat. In former times, Common hippos used to occupy a large territory, extending from the Nile Delta to the Cape. The current range of this species is restricted to protected areas. Hippos are directly killed for their meat, fat as well as ivory tusks, which are highly valued. Additionally, hundreds of individuals are shot annually by humans, who try to escape possible conflicts with these animals, although ditches and low fences are able prevent unwanted encounters. On the other hand, growing human population in the area leads to habitat destruction in a form of settlements, agriculture and roads.
According to the IUCN Red List, the total population of Common hippos is likely to vary between 125,000 and 148,000 individuals. This includes estimates of its populations in the following areas: Western Africa - around 7, 000 hippos; Eastern Africa - about 70,000 hippos; and Southern Africa - around 80,000 hippos, 40, 000 of which live in Zambia (the biggest population of this species among all African countries), 16,000-20,500 animals in Mozambique, about 10,000 in Malawi, 6,900 hippos in Zimbabwe and approximately 5,000 in South Africa. Currently, the Common hippo is classified as Vulnerable (VU) and its numbers continue to decrease.
Due to their immense size and lifestyle, these animals are very important to the ecosystem of their range. For example, by entering the water and coming out, they generate habitats for smaller organisms as well as create routes, through which the rainwater flows during the wet season. When these paths are flooded, lagoons and side pools emerge, where small fish later retreat with diminishing level of water.