Hippos are one of the few animals that genuinely freak me out. Hyenas? Love ‘em. Vultures? They’re my favourite bird! But the thought of meeting a hippo in the wild absolutely terrifies me.
Hippopotamuses – meaning “rive horses” in Greek – should be just as cute and cuddly as manatees. They’re big lazy herbivores who float around in shallow water, and their cartoon depictions are simply adorable. They seem like gentle giants (being the largest mammal after elephants and rhinos), but they are anything but.
Hippo Evolution
Despite looking similar to pigs and elephants, hippos are closer to cetaceans like dolphins and whales. If you look at a whale’s skeleton, you can see that the bones that make up the fins look like hands. Hippos and cetaceans evolved from a common ancestor, and though hippos adapted to walk on land, they still prefer water.
Many hippopotamus species existed in the past, but the only ones that have survived are the modern hippo in sub-Saharan Africa and Egypt, and the pygmy hippo in West Africa. Among the modern hippos are subspecies with varying face shapes.
Biology
Like I mentioned, hippos are the third largest land animal. Weighing between 1365kg and 1480kg, the herbivorous animal must consume around 40kgs of grass a day. While their diet mainly consists of grass and some aquatic vegetation, they’ve also been reported to eat meat. Their stomachs are not suited to meat, but like most herbivores, they’ll resort to carrion if their diet is lacking in certain nutrients.
Though they look like they would be slow to move, they can run up to 30km per hour. Their large canine teeth are used only for combat; their molars do all of the work when they eat.
Hippos have think skin, but very little hair. For an animal that lives in such hot climates, this could lead to a lot of skin issues. To combat this, their skin actually secretes a reddish-brown liquid known as blood-sweat. It’s not sweat or blood, but it acts like sunscreen to protect their skin from damage.
Despite spending most of their time in the water, they’re not particularly good swimmers. They walk along the bottom of lakes and swamps, pushing up from the bottom to resurface every 3-5 minutes.
Behaviour
If you weren’t already in the know, hippos kill more people than lions. They’re incredibly territorial in water, and generally extremely aggressive. They have overturned canoes full of people and brutally killed and injured them. Though they are herbivores, their jaw has a huge amount of force behind it and can leave massive wounds. They’ll even square up against crocodiles, no matter the size.
In a rare, non-violent situation, hippos share a mutualistic relationship with some species of fish. The hippo visits a “cleaning station” and opens its mouth up wide underwater, letting the fish swim around and clean bacteria off of the teeth.
If it weren’t for their aggression, hippos could be somewhat pleasant. But the reason I’m terrified of them is their over-the-top reaction to anything that moves. If you’re in the water with one, it’s already too late for you. You have no hope of outrunning one on land, either. Even crocodiles are scared of them.