Observe birds coming and going through a backyard long enough, and eventually you’ll spot one that has partially white or all-white feathers where there should be color. These birds have a genetic condition known as leucism or, more rarely, albinism, which affects their coloring as well as their ability to survive in the wild. The next time you spot one of these fascinating birds, you’ll know if it’s leucistic or albino.
Birds that lack the color pigment melanin have a genetic mutation called albinism. These birds are often pure white, but in some
cases an albino bird might still have yellow or orange feathers. Those warmer colors are carotenoid pigments, rather than melanin ones, so they’re still present in birds with albinism. The true test of whether a bird is an albino is in its eyes. The lack of melanin allows blood vessels to show through, causing their eyes to be bright pink or red. On the other end of the color spectrum is a genetic condition called melanism, in which a bird has extra melanin pigmentation. These birds appear darker than the typical coloration for their species.
Often confused with albinism is a lesser-known genetic condition called leucism, in which not just melanin, but other color pigments, are reduced as well. Unlike albinism, leucism doesn’t completely eliminate pigment. Leucistic birds appear lighter than normal but aren’t fully white. Sometimes these birds are pale, with an overall lightening of their coloring. In other cases, leucism can result in a bird being pied or piebald—with white patches across its body. Because they don’t fully lack melanin, leucistic birds have normal-colored eyes rather than the pink or red eyes of albinos.
Compared to typically colored members of their species, albino birds are at a great disadvantage. The white feathers stand out against vegetation; thus, without camouflage, albino birds are easier for predators to spot. Their feathers do offer some protection in snow, but unfortunately they reduce a bird’s ability to retain heat. Dark colors absorb heat, light colors reflect it, which can mean life or death in freezing temperatures. Birds with albinism suffer from weak feathers due to a lack of melanin. Their feathers break and deteriorate over time. Albino birds also have poor eyesight—another hindrance. As a result, these birds rarely survive past fledging. Leucistic birds have slightly better chances because they retain some pigmentation. That means the light-colored bird you see in your yard is more likely leucistic than albino.
Either way, it’s a rare and exciting sight when such a unique bird stops for a visit!
Five Facts About Discoloration
1. Genetics determine true albino birds: Both parents have to carry the uncommon recessive genes that produce rare pure white offspring.
2. A pied or piebald bird’s leucistic feathers are rarely in a symmetrical pattern.
3. Typically, leucism affects only dark feathers, so some birds with leucism have white feathers while still maintaining the bright colors of their red, orange, or yellow feathers.
4. A bird is a true albino if its feet, legs, bill, and eyes are pale pink or red.
5. Birds with discoloration may struggle during courtship. Many birds use plumage color as a way to find and recognize potential mates.