A baby hippopotamus is known as a calf, a term shared with the young of other large mammals like whales and elephants. As the offspring of one of the largest land mammals on Earth, the newborn calf is a substantial infant. Its entire existence is tied to the water, which provides both safety and the environment necessary for its earliest survival behaviors. These young animals are born into a semi-aquatic world, immediately relying on their mother for their first crucial breaths and protection.
The Unique Birth and Initial Survival
The journey of a hippo calf begins with a gestation period lasting approximately eight months, or between 227 and 240 days. The mother, or cow, seeks seclusion from the rest of the herd for one to two weeks when it is time to give birth. This isolation allows her to bond with the newborn calf and protect it during its most vulnerable period.
Birth often takes place in the shallow water of a river or lake, though it can also occur on land, with the calf immediately entering the water. The newborn calf is surprisingly capable, able to swim and paddle moments after its arrival. Despite this initial ability, the mother must immediately assist the calf by nudging it to the surface for air, as the newborn can hold its breath for only about 40 seconds at a time.
The dependency on water continues for nursing. The young hippo is able to suckle from its mother while completely submerged underwater. It achieves this by instinctively sealing off its nostrils and ears, a reflex shared by all hippos when they dive. This ability ensures the calf remains protected in its aquatic environment during feeding.
Physical Characteristics and Growth Milestones
At birth, a hippo calf is already a significant size, weighing between 50 and 110 pounds and measuring around 50 inches in length. This substantial weight is approximately ten times that of a human infant. The calf’s growth is rapid, allowing it to reach an average weight of about 500 pounds by its first birthday.
The calf relies on its mother’s milk for the first several months of its life, though it may begin to sample grass by about one month of age. Weaning occurs between six and eight months, marking the transition to a diet of mostly grass. Despite this dietary independence, the young hippo remains closely associated with its mother for a much longer period.
Hippos are slow to reach full maturity. Females achieve sexual maturity between five and six years of age. Males mature slightly later, around seven to seven and a half years old. Young hippos often stay with their mothers until they are roughly seven to eight years of age, before becoming fully independent.
Life in the Water and the Creche System
For the first few weeks following its solitary birth, the mother and calf remain isolated, with the mother displaying intense protectiveness. Once the calf is strong enough, the pair rejoin the larger social group, or pod. This is where the calf is introduced to the social structure of the hippo community. In deep water, the young calf frequently rests on its mother’s broad back to conserve energy and stay above the water line.
Within the pod, multiple mothers and their young calves often form a “creche,” or nursery group, for mutual safety and care. While one mother grazes on land, another will keep watch over the group of calves in the water. This social dynamic increases the protection for the vulnerable young, which are prey for crocodiles and lions.
The hippo calf’s daily life is split between the water and the land. They spend the day resting in the safety of the water, which is their sanctuary from the heat and predators. At night, they follow their mother out of the water to graze on grass, which also serves as an early lesson in navigating the dominance hierarchies and territorial boundaries of the pod.