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Why giraffes have purple tongues

They're not the only animals with odd-colored tongues.

Joshika Komarla
October 9, 2023 @ 7:16 pm

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If anyone asked you to point to the weirdest part of a giraffe, you probably wouldn’t point to the mouth. Their patterned figures, towering necks, and lanky gait make them pretty unique animals. Set against the backdrop of the African Serengeti, the silhouette of a giraffe is unmistakable — and yet, I’d argue that it’s their long and purple-colored tongue that might just be their weirdest feature.

The sauropods of our age: giraffes! Image via Wikimedia Commons.

You’ve seen it on safari tours and animal documentaries—a long, graceful neck stretching toward the heavens, culminating in an intriguingly purple tongue. It’s one of nature’s most puzzling features. But why, you might wonder, does a giraffe have a purple tongue?

Why do giraffes have purple tongues?

Two words: Nature’s sunscreen.

Think about it — Giraffes are megaherbivores. Basically, this means they’re gigantic animals that feed on plants, like elephants.

They also bear similarities with smaller herbivores like cows. This is because giraffes are ruminants; they were built to digest cellulose, the stuff that makes up the cell walls of plants. Again, like cows, they spend a lot of time eating and grazing for food however the only difference? Cows graze grass off the ground while giraffes prefer picking leaves off treetops. They don’t just eat all at once either, adult giraffes can spend over 20 hours a day just walking, tree to tree, and eat anywhere between 15 pounds or 75 pounds of leaves a day.

Under the blaring sun, it isn’t just their body that bears the brunt of heat exposure; their tongues do as well. Since giraffes spend most of their time eating, their tongues, comprised of epithelial cells (the stuff that makes up skin), stick out of their mouth for around 20 hours a day as well. Without protection, that tongue’s bound to burn.

A giraffe sticking out his tongue. Image via Wikimedia Commons.

You might think that the color of a tongue isn’t a big deal. But, in the scientific world, every detail counts. The giraffe’s tongue isn’t just purple; it’s a specific shade that leans more towards blue or black, depending on the lighting. And this distinct hue isn’t a whimsical choice by Mother Nature. It serves a purpose.

To prevent a severe case of sunburn, giraffes house a nifty adaptation on their tongues — melanin.

Melanin, a kind of pigment, is the stuff that makes the giraffe’s tongue dark (purple or blue) colored. Although there are gaps in research still, scientists have long believed that this darkened complexion of the tongue — due to a high density of melanin — is what protects the giraffe’s tongue from the intense ultraviolet rays of the African savannah.

To make things interesting, only the anterior parts of the tongue — the prehensile part — are actually melanized! The middle and posterior parts of the tongue are a run-of-the-mill, baby-pink color.

What’s up with giraffe tongues?

Giraffes tongues have a lot going on. Not only are they purple, but they’re also ridiculously long. An average giraffe tongue measures in at about 50 centimeters – half a meter long!

Again, this comes down to the fact that giraffes are mega herbivores. Giraffes have the distinct pleasure of having almost no competition (except elephants) to contend with for their food. All that grows at heights of 15 feet and above is theirs to eat — especially Acacia, a species of tree commonly found across the Serengeti.

Giraffes often have little to no competition for food. Image via Wikimedia Commons.

A food loved by both elephants and giraffes alike, Acacia leaves aren’t exactly the easiest thing to reach. Both leaves and spines (sharp, pointy, and painful) adorn the branches of the tree. This alternate placement of leaves and spines, poses may pose a threat to some species but to the giraffe — it’s no sweat.

The battle of tongue versus tree

To combat the prickly vegetation of the acacia trees, giraffes employ sneaky tactics. They use their elongated and dexterous tongues to elude the prickly thorns of acacia trees; going straight for the leaves instead. Moreover, giraffes have toughened papillae on their tongues, rendering the surface hardened and rough, thus providing further protection against any potential harm.

Acacias are also commonly referred to as thorn trees. Image via Wikimedia Commons.

Even If the razor-sharp thorns of the acacia manage to draw blood; it doesn’t matter. Giraffes produce antiseptic saliva; it doesn’t matter if they get cut — they just lick themselves to get better!

Odd, not rare: other animals with darkened tongues

Although uncommon, purple or blue tongues have also been observed in other animals across a range of habitats. From Polar bears to lizards, an odd assemblage of animals make up an eclectic group of purple-tongued animals.

Purple-tonged mammals

Okapi

Toss in a zebra, a giraffe, and a deer in a blender, and out comes an Okapi. Armed with the legs of a deer, the pattern of a zebra, and the head of a giraffe, the Okapi is arguably one of the strangest animals alive today.

Yes, Okapis are real. Image via Wikimedia Commons.

Despite their confused appearance, Okapis (also known as Forest Giraffe) is the Giraffe’s only living relative (no, they aren’t also related to zebra and deer). Similar to their cousins, they also possess the same distinctly colored purple/blue tongues.

The Okapi and Giraffe are the only two extant members of the Giraffidae family. Image via Wikimedia Commons.

Okapis live in the canopied rainforests of Central Africa. Forget the sun, the canopy of these forests is so dense that even raindrops don’t make their way to the forest floor. So, what gives with their darkened tongues? Well, it’s still all about sunlight.

So how does sunlight make it to the ground in such a place? It all comes down to treefall gaps. Rainforests are ancient. Trees in rainforests aren’t just decades old — there’s a good chance they are over half a century old. When giant trees like these, with their behemoth girths, fall down, they leave a literal hole in the canopy. Through these holes, emerges the opportunity for new growth; and thus life on the forest floor.

It is in the grounds directly under treefall gaps that Okapis love grazing in; ironically the only area in a rainforest that receives enough sunlight to warrant possessing some form of sunscreen. Again, similar to their cousins, Okapis have prehensile and dexterous tongues that are long enough to clean their own ears.

Okapis can clean their ears with their long tongues. Image via Wikimedia Commons.

Polar Bear

It’s not just the hot places of the world that house purple-tongued animals; cold places have their share too. Up north in the Arctic Circle, Polar Bears are another example of odd tongues in the wild. Interestingly Polar Bears aren’t born with darkened tongues. As babies, they have the typical pink tongues that we do. Over time, this color darkens into a bluish-purple or black hue — the same shade as their skin. Yes, a polar bear’s skin is dark — it’s just its fur that’s whiteish.

A Polar Bear sticks his tongue out. Image via Wikimedia Commons.

This shift to blues and blacks isn’t for the vibes. Think about it, the arctic is a cold, cold place; you need to conserve and absorb as much heat from any source as you can. Of all the colors in the world, dark shades like blue — and especially black –absorb the most light. This helps the bears stay warm — or better retain whatever warmth they have.

Basically, unlike the Okapis and Giraffes of Africa, Polar Bears’ tongues aren’t dark to protect against sunlight but rather to absorb it (funny how that worked out).

Fun fact: Neither their skin nor their fur is actually white! The Polar Bear has black skin and a translucent coat of fur that looks white due to the light it reflects.

Purple-tongued reptiles

Certain reptiles, notably lizards, possess darkened tongues as well. Although not exactly purple, skinks, such as the blue-tonged skink, are popular examples of colored tongues in the reptilian world. Luckily, a lot more research has been conducted on the blue-tongued skinks than on Okapis, Giraffes, or even Polar Bear tongues.

Why do skinks have blue tongues?

For instance, a study from 2018, conducted by researchers at Macquarie University, Australia, found that lizards, like the blue-tongued skink, employ their blue tongues as last-ditch measures against predators.

The lead author for the study, Arnaud Badiane, said that blue-tongued skinks use their colored tongues, in conjunction with other aggressive displays like hissing to scare and disorient predators.

A blue-tongued skink. Image via Wikimedia Commons.

“The lizards restrict the use of full-tongue displays to the final stages of a predation sequence when they are most at risk, and do so in concert with aggressive defensive behaviors that amplify the display, such as hissing or inflating their bodies,” said Badiane, in a press release.

Blue-tongued Skink attacks a Kookaburra figurine.

She further explained that this method of defense was especially effective against aerial predators like birds.  “This type of display might be particularly effective against aerial predators, for which an interrupted attack would not be easily resumed due to loss of inertia, ” explained Badiane.

Another cool fact about these lizards’ tongues is that they’re not just blue — they have UV-blue tongues. Essentially, when seen under ultraviolet light, their tongues radiate an even brighter, more conspicuous shade of blue.

Finally, the same study also stressed on the importance of timing when it came to these full-tongue displays against predators. Badiane explained that for more intense attacks against predators, the lizards would expose a greater section of their tongue, with the rear parts of their tongue, glowing a brighter shade of blue than the tips.

“If (full-tongue displays) performed too early, a display may break the lizard’s camouflage and attract unwanted attention by predators and increase predation risk. If performed too late, it may not deter predators,” said Badiane.

A tongue-in-cheek conclusion

In the animal kingdom, tongues are more than just organs of taste and speech; they are versatile instruments shaped by evolutionary necessity. From the sun-soaked savannas of Africa to the frigid Arctic tundras, from towering giraffes to scurrying skinks, the colors, lengths, and textures of tongues reveal the remarkable adaptability of Earth’s creatures. The giraffe’s purple tongue, a biological marvel that thrives under the unyielding African sun, encapsulates this adaptability in a striking way.

We might not yet fully know why giraffes — or any of the many animals that have purple or blue tongues — have darkened tongues however, we may take solace in the fact that giraffes certainly seem to be winning the battle of tongue versus trees in the Serengeti.

So there you have it: the low-down on why a giraffe’s tongue is purple—it’s a full-blown survival tool. Who knew that the secret to surviving the African heat was, quite literally, on the tip of a giraffe’s tongue?

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