Kristin Hugo, Global Animal
There are many coat mutations that affect animals that can make them black, white, or other colors. In the 1950’s, the commander of the Seneca Army Depot saw one deer with a completely white coat. He was so inspired by the mystical-looking creature that he forbade any of the GI’s from shooting any white deer they saw. Today, there are about 700 deer at the depot, 300 of which are white, making it the largest population of white deer in the world.
The deer in Seneca were saved by their striking coats, but often such a dramatic mutation can be dangerous for animals. For example, white animals (and people) are more prone to getting skin cancer and burn in the sun. Often if an animal looks different from the rest of the herd, it will be picked out by predators, or can even be outcast by the other herd members. For this reason, the rare genes for coat variation don’t tend to continue in a non-domestic population.
Still, when an animal has defective genes for pigment formation, it’s hard not to be fascinated. The mysterious black panther and the mystical white tiger capture the imagination, as do other strangely-colored animals.
To understand coat mutations, first it’s important to understand the pigment called melanin. This is what makes skin and fur dark. When you spend a lot of time in the sun, your body produces melanin to protect your skin from overexposure. When you spend a lot of time out of the sun, your body breaks down the melanin and you become pale again, so that you can absorb the vitamin D you get from sunlight. When you are born, you already have a certain amount of melanin in your skin in accordance with your genetics, and of course, animals and humans are affected by mutations.
The various types of mutations include:
Albinism is a mutation that causes an absence or defect of an enzyme that is involved in producing melanin. Albinos are often mistaken for leucistic animals, which are different in that leucism causes an animal to lack all pigmentation. The white deer of Seneca are not albino, but leucistic.
The black panther is not a species. A black big cat referred to as a black panther is one that has melanism, which causes abnormal amounts of black pigment to show up in the skin and fur. Most often these are leopards, and you can still see their spots in certain lights. Melanism has also been observed in other animals, such as squirrels and servals.
Piebaldism means animals that have large splotches of color, but the rest is white. Sometimes a piebald animal will be a dark one with partial albinism, where only parts of its body are devoid of pigment. Other times, it will be a light-colored animal with partial melanism, where parts of its body have a higher concentration of melanin. Patches occur in localized areas of the body during embryo development.
When an animal has a dark pattern, like stripes or spots, sometimes an increase in melanin will result in abundism. This makes the dark markings thicker and more prominent. In this zebra, the black stripes have overtaken much of the white on the animal.
Erythristic animals have an excess of red pigmentation and sometimes a decrease in other pigmentation. This is an extremely rare example of a erythristic leopard.
There are many other coat mutations that result in a wide variety of startling animals. Concentrations of other pigments produce yellow, blue, and cream-colored animals. For a list of genetic colors and terms that big cats (like lions and tigers) and other animals have exhibited, check out http://www.messybeast.com/genetics/mutant-bigcats-terms.html