Why Does Find a Hippo Mouth Open? Let’s Explore

In the mammal group, the hippo is a popular figure that we discuss a lot. Greek call them by river horse and this giant animal can broaden their jaws quite largely. When it broadens its gape, it seems horrible and you will be astonished to see this incident. They are the third animal in the list of mammalian who can widen their lips that much wider. So, let’s read the article to know more about the open mouth of a hippo.

why does a hippo have an open mouth

How wide can a hippo open its mouth?

The hippopotamus is an animal that can broaden its jaws extremely wide and do you know how much it is! They can open it about 180 degrees. Usually, they make it this largely when feeling that they are threatened by something or somebody.

To show their territorial dominance, it also works as a signal. When they open their jaws, you can see the whole inner along with the sharp teeth which may mirror their aggressiveness.

Hippo open mouth at the widest angle

Guinness world record about the hippo’s open mouth

Among all the land animals, the River horse has a Guinness record of opening its mouth most largely. It is near about 180 degrees. A mature male hippo can make it about 1.2 meters which is near about 4 feet.

Hippopotamus open mouth

What is the measurement of hippo’s opened jaws in feet?

It is rare you can find a hippopotamus opening their jaws with their canines and incisors. Canines are initially measured about 71 cm (28 inches) and they grow more day by day. It is recorded 122 cm (48 inches) for the largest canine.

Hippo can stretch its jaw 4 feet wide which is huge. They want to protect themselves with their strong teeth. They can tear a human in part and break a boat into two parts by their strong bite.

The animal with the widest opened mouth

There are some animals whose jaw structure is made as they can make their gape so much widely that we humans cannot imagine.

If we talk about the animal both in water and land then it is a bowhead whale who can open its jaw 16 feet long, 12 feet high and in width, it is 8 feet. They have a heavy tongue that weighs 1 ton which is equivalent to 900 kilograms. In the case of land animals, the winner for the largest opened mouth is a hippopotamus.

Do mother hippos carry their babies in their mouths?

Most of the mothers on the animal planet are concerned to save their babies from any kind of danger. River horses are not different. Hippo mothers are very much protective and careful of their calves.

If they face any trouble with their children, they must attempt to save them. In Kenya, a wildlife photographer found a hippopotamus carrying its calf in its gob and cross a waterbody. We may think that the baby gets hurt but its mother reached the opposite side safely.

Mom hippo with baby

The mystery of hippo opens their mouth for their babies

Sometimes you can see river horses sitting on the ground while they keep their jaws unclosed. And if the baby is around it, you may see it to massage its mother’s gob. Generally, it seems weird. But for the hippopotamus, their pattern of showing affection is different. A baby river horse named Fiona is captured in a video while massaging her mother’s mouth.

Fiona explores her mother’s mouth

The reasons behind hippo’s yawning

We all know that river horses stay most of the time of a day in the water body. Because of being staying that long period under the heat of the sun their brain gets heat. An experiment was held probably on 40 hippopotamuses in a river named Luangwa.

It is observed that they yawn more at the period of dusk while the sun becomes heatless. Hippos yawn for cooling their brain. They need to make their brain gentle and yawning makes it soothing.

Hippopotamus yawns

Why do hippos sit with their mouths opened?

Hippopotamuses fight

There are several reasons that hippo sit by opening their jaws. Here are some mentioned below:

  • To show their aggression most of the time mother hippo keep open their gape unclosed. When they feel like something is going to happen or their young one is not safe, they do it repeatedly and intentionally
  • They do this for showing their dominance over humans or any other enemies. For delivering a tush they need to extend their gape too.
  • Sometimes hippopotamus enlarges their lips to show affection to their child. Moreover, they keep their lips broad while you carry food for them.
  • They wait by keeping their jaw extended until you drop the food like a watermelon on its gob.
Hippopotamus Yawns


River horses have a special territory. When it sees that something is threatening in its area, it enlarges its jaw to show its power to the enemy. That is the basic reason behind they stay in the facial position. To prove that they are well aware of their safety, hippos make this kind of expression.

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Clay Traynor

Hello, I am Clay, a Zoophilist, Researcher, and Writer. I Write interesting and unknown facts about animal life, habitat, and health.

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