Between the brown trunks and dappled shadows of trees, a ghostly white shape steps quietly. Its snowy coat and delicate movements are reminiscent of a heraldic unicorn. But this striking animal is no mythical creature - it's a piebald white-tailed deer!
|A piebald white-tailed deer with normally-pigmented companions.|
Image public domain by the U. S. Fish and Wildlife Service via Wikimedia Commons.
Piebald deer, however, have a genetic mutation that causes pigmentless, white patches throughout their coat. The skin beneath these patches is also pigmentless, appearing pink. The effect is similar to white spotting patterns in horses or rabbits.
Piebald is a broad "catch-all" term for animals with unusual pigmentless patches on their bodies. It is also known as "white-spotting," "pied," "partial-leucism," "partial-albinism," or "part-colored."
Because "piebald" describes only the appearance of an animal, but not the specific underlying condition, the cause of piebaldism varies greatly by species and within species. Piebald coloration can be caused by genetic mutations, developmental abnormalities, injury, disease, and even nutritional deficiencies. Horses, for instance, display over five different forms of piebaldism, all under the influence of different genetic and developmental mechanisms.
|A piebald deer sighted in VA. Image public domain via Wikimedia Commons.|
|A chart showing three patterns of piebaldism in white-tailed deer. |
Many wild piebald deer show the Type 1 pattern, whereas many piebald deer bred on deer farms show the Type 3 pattern.
Image copyright Jane Marlow.
Piebald deer have been sighted throughout Maryland, even in Baltimore City! While Maryland's DNR website states that around 1% of deer are piebald, this percentage may be higher in local or isolated populations.
|Two piebald deer. Image public domain by the U.S. Fish and Wildlife Service via Wikimedia Commons.|
Despite the disadvantages of piebaldism that may occur in the wild, humans have long considered piebaldism an aesthetically appealing trait and have selected for it in domestic animals. The vast majority of domesticated species are commonly found in piebald patterns, including cows, goats, sheep, horses, dogs, cats, pigs, alpacas, ferrets, chickens, ducks, pigeons, finches, and even domestic parrots, such as cockatiels.
|Ancient Egyptian art depicting domesticated cattle with piebald patterns.|
Image public domain via Wikimedia Commons.
So next time you see a flash of white among the shadowy hues of the forest, look closely! You may catch a glimpse of a rare piebald animal!
Diseases and Parasites of White-tailed Deer: Piebald Anomaly. Maryland Department of Natural Resources. Web. 17 Jan. 2014. <http://www.dnr.state.md.us/wildlife/Hunt_Trap/deer/disease/ddpbald.asp>.