Biologists Spy ‘One-in-a-Million Anomaly’ Sprinting Through Texas Desert

Rare black mule deer
The tiny mule deer is at bottom left.Texas Dept. of Parks and Wildlife

Most mule deer are brown, but this "rarest of the rare" was black, wildlife officials said.

A team of biologists were ecstatic after spying a “one-in-a-million anomaly” in the desert of west Texas.

In video posted to Facebook, a small mule deer can be seen bounding up the side of a mountain.

“The rarest of rare,” said the Texas Department of Parks and Wildlife this week.

The rarity was not the mule deer, but its color.

Most mule deer are brown. This one is black.

The fawn has a rare condition that resulted in darker fur. Melanism, the department said, is “a rare random genetic anomaly believed to be caused by mutations in the melanicortin 1 receptor gene (MC1R) which leads to an over production of the pigment melanin.”

It is far more rare than albino coloring, the department said.

“It’s difficult for biologists to quantify the number of mule deer that have this condition, but it’s estimated to be around 1 in several million – making it even more rare than an albino (all white hair) or piebald (white spotted) mule deer. A one-in-a-million anomaly.”

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