Natural History

From MSNBC:

When Paolo Torchio set out across Kenya’s Masai Mara National Reserve a few weeks ago, it was just a typical Thursday morning for the veteran wildlife photographer, who has lived and worked in Kenya for two decades.

Torchio is intimately acquainted with the beasts that wander the nearly 600-square-mile game reserve, so he was astonished to see a terrier’s face poking out of the tall grass.

“I was wondering, what is this dog doing?” Torchio said. “And when it came out from the grass, that was a surprise.”

The hirsute creature that emerged was clearly not a dog. The animal had all the markings of a Thomson’s gazelle (a type of antelope) — but, like that old song from “Sesame Street,” one of these kids was not like the others. This animal was covered with a strange, thick coat of hair, in stark contrast to the sleek Thomson’s gazelles in its company.

“The funny aspect was that it wasn’t affecting the relations with the other gazelles,” Torchio said in a phone interview. “There was no problem between her and the other one.”

Torchio crept alongside the shaggy creature for 15 minutes, snapping pictures, but eventually the spooked animal sped away. The Italian photographer spent the next five days trying to find the gazelle, but to no avail.

Experts are not quite sure what to make of the fluffy little gazelle, especially since Torchio’s photographs are the only known example of such a beast.

“From the looks of it, it’s definitely a Thomson’s gazelle, and I would say it’s a younger female, based on the body and the horn size,” said Lanny Brown, a zookeeper at the Phoenix Zoo in Arizona, and the man in charge of maintaining Thomson’s gazelle populations for all of North America.

Brown told OurAmazingPlanet that neither he nor any of his colleagues knew of any documented cases of a hairy Thomson’s gazelle, or any kind of antelope, but he suggested that perhaps the animal is suffering from hypertrichosis, a condition — once known as ‘werewolf syndrome’ in less politically correct times — that can affect both animals and humans. As the name suggests, a genetic slip-up causes excess hair to grow all over the body.

Or, Brown said, it could be that the gazelle has Cushing’s disease, a hormonal disorder seen in various animals. The condition is particularly common among horses, and the affected animals often look like an overgrown poodle.

Despite its unusual hairiness, Brown said, the fact that the little gazelle has made it this far bodes well for its future.

“Generally, a mother gazelle is pretty paranoid if something is wrong with a calf. It takes a lot of energy, effort and risk to raise a calf,” Brown said.

The fact that this furry gazelle wasn’t rejected by its mother suggests that whatever is causing the excess hair either wasn’t present when the gazelle was born, or that the condition isn’t causing obvious health problems.

Brown added that he doubted the extra whiskers would slow down a Thomson’s gazelle, a creature for whom speed is a key weapon against predators. The spry mammals are among the fastest on land, running at speeds up to 55 and 60 mph.

And even though this female may look a little funny, Brown doesn’t foresee any trouble come mating season.

“Male antelope aren’t terribly picky,” he said.

I am skeptical that this is Cushing’s disease. I’ve never heard of it in a gazelle, and because gazelle’s are hunted by basically everything in the bush, I don’t know how one could survive all the Cushing’s disease symptoms. Just having shaggy hair isn’t the only symptom of the disorder. If that is all there was to it, I doubt we’d call it a disease. Horses with Cushing’s are shaggy because they fail to shed out in the summer. These gazelles normally don’t get super shaggy at any point in their lives.

So this suggests that this is result of a something genetic.

If so, then there are many questions:  Is the result of a recessive or dominant allele? What is the exact genetic basis for the trait– a gene or a several genes? Can the mutation or mutations be located?

And then of course:  Does this trait have any obvious disadvantages or even possible competitive advantages? If it has advantages, well, those are the traits that evolution is made of.

I would not assume that having that much shaggy fur around the eyes would be an outright disadvantage in the tropical savanna. During the summer, many horse owners use specially made halters that cover the eyes in much the same way as this gazelle’s beard. These halters keep the flies out of the horse’s eyes.  I have seen horses get nasty infection where the flies have nibbled around corners of its eyes. In East Africa, the number of nasty flies has to be much greater, and this gazelle would have have advantage in keeping the flies out of its eyes– and infections down.

Of course, a male gazelle with a beard might have trouble breeding. The female might not have problems attracting a mate, but female gazelles are much more discerning about their breeding partners.  One of the factors that drives the ornate horns and antlers in ungulates is female selection. And if you look like a horned schnauzer, I doubt that you’d get many dates.

If this trait is recessive and this gazelle manages to produce a few offspring to adulthood, chances are relatively high that some of its descendants will have these traits.

The simple reason is this:  Thomson’s gazelles are harem breeders, and harem breeding animals have a population structure that is generally concentrated around a few sires. That means the chances for closely related individuals in the same population to breed with each other is quite high.

It could be that the initial sire that carried this trait has already passed his genes on into the population. If that is the case, then the chances are still relatively high that some more bearded gazelles could be born.

My guess is that if this a genetic mutation, it is recessive. If it were dominant, it would be very common.

But we just don’t know.

In the end, it could be nothing more than a hormonal disorder (maybe like Cushing’s) or a somatic mutation.  In either case, the trait cannot be passed onto the next generation, except perhaps as a tendency to develop similar hormonal disorders.

We just don’t know.

But it’s certainly got my curiosity piqued.