The Hippopotamus

The hippopotamus has the biggest yawn in the animal kingdom. It is one of the most dangerous animals in Africa. Females are especially aggressive when they have young. As well as seeing off predators, females have to protect their young from being bullied by grumpy males. Mothers teach their young to stay close, giving them a head butt or a nip if they wander off track, and if a mother needs to leave the creche for any reason she places her calf with a female baby sitter.

Hippopotamus live in groups of 15 or more females and subordinate males, governed by a dominant male. He will scare off any challengers by opening his mouth very wide and showing his enormous 50cm long canine teeth. It is an awesome sight, since the hippopotamus has by far the largest mouth of any animal outside the oceans.