There are probably three things about blue tigers that are worthy of coverage (a) the interesting writings of an early tiger hunter and missionary, Harry R. Caldwell, which reveal a lot about us and our relationship with wild animals (b) the genetics involved and (c) the rarity of this animal.
The writings as set out by Sarah Hartwell on her website are fascinating if a little gruesome for an animal lover. Caldwell was both a missionary and a killer of tigers. These two careers are probably still compatible, sadly. He loved the appearance of this tiger,
“The markings of the animal were marvellously beautiful. The ground colour seemed to be a deep shade of maltese, changing into almost deep blue on the under parts. The stripes were well defined, and so far as I was able to make out similar to those of a tiger of the regular type.”
Yet he was determined to kill it, to possess its skin and saw nothing unusual in these two conflicting points of view. As soon as he killed it (mercifully he never managed to) he would have extinguished that which he found beautiful. It would seem that he only found the pelt, the tiger’s hair on its skin beautiful, the rest he could willingly throw away. But this seems strange as the two are one. And being a missionary should have told him that it was wrong. He was tracking the blue tiger in China, Fujian Province, in the South:
Apparently, the few blue tigers that there were at that time (and less now of course – are there any left? I’d be surprised if there were) were referred to as, “blue devils” (“The World Of The Tiger” by Richard Perry), as they were often man eaters. I am not surprised. They were, it seems, endlessly hunted by mankind and/or had difficulty in finding its usual prey. We like to hunt the rare and precious and possess it and in doing so we make it rarer and ever more desirable and vulnerable. Perhaps these rare tigers were injured by hunters and forced to go for easy prey, humans? These are the kind of reasons why big cats become man eaters (see Man Eating Leopard).
Caldwell referred to the blue tiger that he and his colleague tracked as,
the “Great Invisible” [referring to elusiveness of tigers] and it seemed impossible that we should not get him sooner or later, but we never did.”
The blue tiger, indeed any tiger, is still the great invisible, avoiding humans if possible. And here is the interesting dichotomy. This cat is supposed to approach humans to attack and eat them and also be near invisible to us. What is it? It is both. Both forms of behavior are in reaction to our behavior. The blue tiger will avoid us as we are not its usual prey and we are dangerous to it. But, as mentioned if we injure the cat or destroy its prey it will chance its luck and look to us as easy prey.
The Blue Tiger Appearance
There are other genetic mutations in the tiger world. Take the endangered white tiger. As in the domestic cat world there are genetic mutations, which are often due to recessive genes that produce abnormal characteristics. Here is yet another seeming dichotomy. In the domestic cat world, the cat fancy, we seize upon interesting genetic mutations and sometimes breed more of these rare cats. There are numerous examples: Devon Rex (crinkly hair) and Sphynx (little or no hair) and many more. Yet in the wild cat world we shoot them and hang them on the wall or place the skin on the floor. The motivation is, in fact, the same. We like to possess the rare. We cannot possess a live blue tiger – too problematic and too expensive so we kill it and possess what is left of the tiger, the rare bits, the skin and sell the penis for medicinal purposes! The domestic cat can be possessed, the law allows it, and so we simply breed more of what is or was rare.
What causes the tiger to become blue? This tiger retains its stripes. Both the stripes and the ground color become blue or slate grey. More accurately dark grey stripes and bluish fur. People are not sure of the answer to this question. Cat genetics for domestic cats is not fully understood. The blue tiger is also called the Maltese tiger after the cat fancy term meaning slate grey coloring after, apparently, cats in Malta where there is a preponderance of them. A typical purebred cat that is Maltese colored is the Russian Blue. It only comes in this color. There are other Grey Cat Breeds. These are the genetic possibilities, proposed, that produce the blue in the blue tiger:
- I think it fair to say that the dilution gene is definitely involved. This gene is commonly encountered in the cat fancy, as mentioned. The famous blue British Shorthair is a classic example. The dilution gene turns black to blue/grey. So the black hair tips of the stripes is turned to slate blue/grey. That makes sense.
- The Wikipedia author (Sarah Hartwell?) says that it has been proposed that the non-agouti gene is also present. But this would almost eliminate the stipes and that is not the case, so that it seems can be ruled out.
- Wikipedia also propose that a variant of the non-inhibited pigment (“chinchilla “) allele may be at work.
I am going to stick my neck right out and propose the following. I expect to be shot down in flames! The tiger is basically a tabby cat. The genetics for mackerel tabby cats is A (agouti) + B (black) + D (dense coloration) + Mc (tabby gene) (Robinsons Genetics 4th Ed). If we dilute that we get a cat like the American Curl on the left below (the cat on the right is non-dilute version or brown mackerel tabby:
The Rare Blue Tiger
Well, the cat is rare because it is a recessive gene that pops up (popped up, past tense perhap s) from time to time but otherwise suppressed. Also it is or was hunted. There are no blue tigers in captivity (src: Messybeast). There no photographs of this tiger. There are no pelts in museums. A blue tiger was reportedly sighed during the Korean war (but no current evidence exists of this, it seems). And they have been reportedly seen in Burma, the land where they kill tigers for exportation of tiger parts to China (once again no evidence). So the wrong place to be a blue one. I doubt this tiger exists anymore. I would like someone to disabuse me of that notion by leaving a comment, please.