Friday, March 18, 2011

Black Fawn

What is the rarest color abnormality in whitetail deer?  I would have guessed albino deer, the lack of pigment - and I would have been wrong.  The answer is melanism.  This mutation creates a darker deer, varying from dark shades of brown to almost totally black.

The website of the photographer R. M. Buquoi  has an array of beautiful nature photographs including these pictures taken from his urban home.
"I took the photos of the black fawn near Austin, TX. That area of central Texas seems to have a concentration of black "white-tailed" deer, although it is still extremely rare to find them. This is a wild deer, but resides in a greenbelt near a neighborhood. I took the images when the deer were roaming through the neighborhood. The two fawns in the photos are twins, but only the one is black."
Family- Click to Enlarge
Melanism, the production of excess melanin, is usually genetic but occasionally occurs from environmental conditions or diet.  Melanistic deer can run the spectrum from a darker brown to almost black.

Pigment variation in animals can range from none to excessive.  Albinism is a congenital lack of pigmentation and is known to effect all vertebrates.  This is a disadvantage because the animal lacks protective coloration and the loss of eye pigmentation allows unfiltered light into the eyes, impairing the vision in bright light.   Both are a disadvantage when you are trying to avoid predators.

Melanistic deer are very rare unless you are living close to San Antonio, Texas.  There the variation is very uncommon although they have more melanistic deer than the rest of the country combined.  Unlike albino deer, melanistic deer may have had a survival advantage, living in the deep shaded draws where a dark color would help them hide from predators. 

One question unanswered by the information at Northamericanwhitetail.com is about breeding.  What do the "normal" whitetail deer think about this variant?  Do they become attracted by appearance or other factors?  The fact that they are more common in an area of Texas suggests that they breed successfully.  The fact that melanistic deer continue to propagate in the region of eight counties suggests that appearance isn't an important factor.

One thing seems sure - their momma's and siblings don't care.  They are treated as family, suggesting that smell and other traits overrule the fact that they look different.  If only humans could get along as well. 

Visit the website R. M. Buquoi for other beautiful photographs. Thanks to Larry Whiteley of BassPro sending me the story.