Is this animal albino?
From time to time, we find photos of animals with white coats that don’t typically have white coats. Are these animals albino?
Albinism is caused by a genetic mutation whereby cells called melanocytes are “switched off” and fail to produce the pigment melanin. Melanin colors hair, skin, feathers, scales and eyes. Albinism can occur in any animal that has melanocytes, including mammals, reptiles, amphibians, birds and fish. Albino individuals may appear pure white, or may just be lighter overall than non-albino individuals.
Albinism is a rare condition, and there are several more common explanations for light coloration in animals. One is leucism, a condition caused by recessive genes that restrict the creation and/or distribution of pigment-making cells throughout the body during early development. Leucistic individuals may have light coloration overall, or they may have a light patch or patches scattered across the body.
Since either condition can result in individuals that appear white or very light in color, how can the casual observer tell the difference? It’s helpful to look at the eyes. Eye pupils normally look black because pigments at the back of the eye absorb light. In albino individuals unable to produce melanin, however, eyes appear red because light is reflected off blood vessels in the retina rather than being absorbed by pigment. This is why albino individuals experience a heightened sensitivity to light, and often some degree of blindness. Since the melanocytes that produce eye color are not affected by leucism, leucistic individuals typically have normal eye color.
So, is the deer in the photo above albino or leucistic? Based on the dark eyes, it’s more likely leucistic.
White deer (albino or not) are protected from hunting in certain places, including Wisconsin. Why? White deer are not a special “breed” or subspecies, but they do hold social significance. People love seeing them, and some believe that they are good luck or magical. Certain areas of the state are now known for their white deer, and we are likely to keep spotting them on Snapshot Wisconsin cameras from time to time.
More info on color variation in animals:
- Albinism and Leucism: Origins and Differences
- Causes of Color: Biological Pigments
- What colour is that bird?
- Piebald mystery solved: Scientists discover how animals develop patches