When I was in Africa, I saw a lot of hippos, and one thing that I couldn’t believe was the size of their teeth. Hippos are the second-largest land mammal globally, so it doesn’t seem unusual that they have large teeth. However, when you consider their diet, large teeth seem unnecessary and out of place.
Hippos use their teeth to feed on vegetation. Their molars grind vegetation to break down the layers of cellulose, allowing them to digest it easier. The canines are used to break into hard fruits. Hippos are territorial, and during mating season, males will lock teeth with others to show their dominance.
If you want to know more about hippos’ teeth, please read on. Perhaps there is an alternative to simple dietary use.
Like many mammals, hippopotamuses have more than one tooth type, and each type has a different purpose. They have large flat molars, canines, and large incisors or tusks.
To understand why hippos have large teeth, we must look at their diet and lifestyle. Hippos are predominantly herbivores, coming out of the water at night when the land has cooled down to graze on grasses and fallen fruit.
Hippos use their lips to pull the grass from the ground. Their large molars are then used to grind the vegetation and break the outer cellulose layers. This is important as they do not produce the necessary enzymes to break down cellulose in the gut. Hippos have a three-chambered stomach, consisting of a parietal blind sac, the stomach, and the glandular stomach. A hippo will starve to death if its molars are worn down too much to grind vegetation.
The longer canines, which measure up to 50 cm, are used to crack open fruits, so they are easier to swallow. In captivity, hippos are fed large fruits like watermelons. They use their sharp teeth to break the outer flesh, and their strong jaws crush the fruit into smaller pieces. Hippos then tip their head upward so the juices from the fruit can be swallowed.
As well as using them for eating, hippos also use their canines in battle. This is what makes them the most dangerous animals in Africa. A hippo can quickly kill a lion by crushing its skull in its massive jaws and causing large puncture wounds with its sharp tusks.
Male hippos will also fight one another to claim territories and the right to mate with nearby females. They will open their jaws to their widest point and lock teeth. Wrestling is also part of this dominance display but does not last more than a few seconds at a time.
Hippos have one of the largest mouths of any animal and can open their jaws 180 degrees. They have a bite force of 1,800 pounds per square inch, similar to most alligators. Hippos kill more humans each year in Africa than lions and sharks combined.
While it was initially believed that hippos were exclusively herbivorous, in 2015, experts discovered that hippos occasionally feed on animal carcasses, even those of other hippos.
The tusks of male hippos are almost twice as long as those of female hippos. Often, this is the easiest way to distinguish between the sexes, particularly with juveniles.
What’s In A Tooth?
Adult hippos have between 38 and 42 teeth. Most of these teeth are molars and premolars, with four sharp canines or tusks (2 pairs on each jaw). Many adult hippos will retain some of their milk teeth, so some individuals have more teeth than others.
Hunters prize hippo teeth due to the value of ivory. Unlike other animals with ivory tusks, hippo tusks do not yellow as animals age.
Their teeth are excluded from a multi-national ivory trade ban, meaning hunting outside protected areas is legal, as is the sale of hippo teeth.
A hippo’s teeth grow continuously throughout life and will be worn down by grinding against the upper canines.
Threats and Conservation
Hippos face many threats, primarily from human activity. These include:
- Expansion of farmland
- Fencing across their grazing land
- Road extensions
It is estimated that in 2002, approximately 2000 hippos were killed by poachers. The ivory tusks and thick skin are highly prized. Uganda alone exported 5.5 tons of hippo teeth in 2002.
Hippos are currently listed as ‘vulnerable’ on the IUCN Red List of Threatened Species. While new hunting laws ban the import and export of ivory, hippo teeth are not included in this ban, so hunting continues outside protected areas.
In the early 2000s, the hippo population in the Democratic Republic of Congo declined by a staggering 95% due to habitat loss and hunting.
Charities like the African Wildlife Foundation are actively engaging with local communities to establish better boundaries to keep hippos away from farmland and prevent the need for people to shoot hippos.
This includes things like digging shallow ditches and constructing fencing around cropland. They also provide funding for national parks to create and manage protected zones where hunting is illegal.
Haines, B. (2020, May 6). 57 Huge Hippo Facts: Complete Guide to the Massive Hippopotamus. Retrieved from Storyteller Travel: https://storyteller.travel/hippo-facts/#:~:text=Here%20are%20a%20couple%20other%20hippopotamus%20facts%20about,by%20constant%20grinding%20against%20the%20shorter%20upper%20canines.
Rank, S. (2021). The Hippo’s Teeth And Its Diet. Retrieved from Science Rank: https://science.jrank.org/pages/3340/Hippopotamus-hippo-s-teeth-its-diet.html#:~:text=Hippos%20have%20a%20huge%20mouth%2C%20measuring%20up%20to,reach%20a%20length%20of%203%20ft%20%281%20m%29
St Lucia South Africa. (2016, October 17). Hippo Facts & Information. Retrieved from St Lucia South Africa: https://stluciasouthafrica.com/hippo-facts/
Study.com. (2019, April 19). Hippopotamus: Definition, Diet, Teeth & Facts. Retrieved from https://study.com/academy/lesson/hippopotamus-definition-diet-teeth-facts.html