Video: Texas Biologists Spot “One-In-a-Million” Deer

While Texas Parks and Wildlife (TPWD) biologists were conducting wildlife surveys in the Trans-Pecos area when they spotted something extremely out of the ordinary—a melanistic mule deer.

According to the TPWD Trans-Pecos Wildlife District Facebook, it’s difficult for biologists to quantify the number of mule deer with this condition. It’s estimated to be around one in several million. A melanistic muley is even rarer than an albino or piebald (white spotted) mule deer.

Melanism is a recessive genetic trait caused by mutations in the melanocortin 1 receptor gene (MC1R). A 2020 study from Germany explains that the ratio and distribution of the pigments eumelanin and pheomelanin define the basic coat coloration of hair and skin. The mutation of MC1R increases the production of eumelanin to create a uniformly black or dark coat. While this condition will affect fur-covered critters, it most commonly occurs in birds, like this turkey harvested in 2020.

Just to the east of the Trans-Pecos area is the Edwards Plateau Ecological Region. According to the National Deer Association, this is where the highest known concentration of melanistic whitetails exists. But melanism in muleys is an even rarer phenomenon, making this sighting truly one-in-a-million.

Feature image and video via TPWD district 1 biologists J. Etchart & J. Weaver.