A few weeks ago, I wrote about April the giraffe and one of the facts about giraffes was their blue tongue. My friend Janice quoted a website that suggested that giraffes had blue tongues to guard against sunburn.

That didn’t seem logical to me, so I decided to do some research to see what other animals had blue tongues and why. The first thing I discovered was bluetongue disease, “a non-contagious, insect-borne, viral disease of ruminants, mainly sheep and less frequently cattle, goats, buffalo, deer, dromedaries and antelope,” said Wikipedia. Interesting, but not what I was after.

As a dog person, the first thought I had were the dog breeds, Chow Chow and Chinese Shar-peis. Both of these breeds have blue tongues. According to the website, homewardbound2u.rescuegroups.org, over 35 dog breeds have, or can have, spotted tongues, but there was no reason cited and I couldn’t find any reason why Chow Chows and Shar-peis had solid blue tongues.

The article also mentioned that several breeds of cattle had blue tongues, so, I Googled “cattle breeds with blue tongues” but found nothing. I tried rephrasing it, and found answers.com. This site said, “The majority of cows have a tongue that is nearly black in color. This is because of the dark pigments that make up the tongue.” That wasn’t quite was I was looking for. Uk.answers.yahoo. com offered an answer from an unidentified reader, ” … not all of them just some black angus a lot of time will have a black tongue. Jerseys can have a black tongue. It just varies in the cows.” Still no answer to why a cow, or any animal, might have a blue tongue. (and all the cows I’ve ever seen have had a pinky-white tongue).

I abandoned my bovine search and broadened the search to include all animals. Quora.com says flat out, “For protection. In the animal kingdom animals use bright colors to indicate poison.” This seems reasonable for lizards like the blue-tongue skink, which has a bright blue tongue, but certainly doesn’t explain the animals with the purple-blue color tongue. Mnn.com expands the information on lizards, citing the blue-tongue skink, as well as the Eastern blue tongue lizard, the pygmy blue tongue lizard and the bob-tailed blue tongue lizard. The writer then moved on to the subject of giraffes.

“Some say that it provides sun protection for their tongues, since they don’t get much shade up there above the trees — a great answer for why giraffes have blue tongues, but again not an adequate explanation for why okapi (the giraffe’s cousin with shorter necks) have blue tongues too. Some believe that giraffes have blue tongues to scare away predators too, but that answer doesn’t make much sense to me.”

It doesn’t make sense to me, either. Protection from what? I can’t see a predator worrying much about the color of a giraffe’s tongue, nor can I see a giraffe pausing in flight to stick out its tongue at a lion.

A couple of websites said that black bears had blue tongues, but all the photos I could find of black bears showed them with pink tongues.

I did discover that polar bears had dark tongues, ranging in color from blue to purple to black. Frontiersnorth.com has an article that say polar bears have black skin, “which helps to keep the bear warm by absorbing heat from the suns rays. Working from there, and recalling that giraffes have blue tongues to supposedly prevent sunburn, does the polar bear have a dark tongue to help keep warm? I’m not inclined to believe either of those statements.

None of the sites I browsed had a definitive reason why some animals had one color tongue, and some another. It reminded me of a theory I heard often growing up. Common wisdom had it that if the roof of a dog’s mouth was black, the dog was a purebred. After seeing the inside of many dogs’ mouths over the years, I can say that that’s not true, but again, why do some dogs have a dark roof-of-the-mouth and some have pink?

It all made me think of this quote from Dylan Thomas’ “A Child’s Christmas in Wales,” ” … and books that told me everything about the wasp, except why.”

So, multiple websites with various theories, but nothing definitive on why some animals have blue tongues while others do not. The blue tongue in certain animals is a quirk of nature, an interesting fact that’s fun to share, as long as nobody asks why.