Off-Colored Birds

By 2019 Avian Care Intern – Adam Petrucco

Leucistic Canada Goose on the left

Have you visited the W.K. Kellogg Bird Sanctuary recently and saw a bird that looked unusual? Was the plumage lighter than normal, making the bird stand out from other members of its species? You may have spotted one of the rare leucistic birds that visit the Sanctuary!

            What does it mean to be leucistic? Leucistic animals have a condition called leucism, which is defined as, “an abnormal condition of reduced pigmentation affecting various animals (such as birds, mammals, and reptiles) that is marked by overall pale color or patches of reduced coloring and is caused by a genetic mutation which inhibits melanin and other pigments from being deposited in feathers, hair, or skin.”¹

Leucistic Mallard Duck

            Being leucistic is not the same as being albino because leucistic animals still have melanin pigments to some degree. This is as opposed to albinism which causes an animal to lack all melanin pigments. The easiest way to determine if an animal is leucistic or albino is to look at the eyes. Leucistic animals still have pigment in their eyes, this means that their eyes will appear to be colored. Albino animals on the other hand will not have pigments in their eyes, because of this the red colors of blood vessels in the eyes will give the eyes a red or pink color.²

Leucistic Trumpeter Swan

            In birds, leucism is not only limited to the color of a bird’s feathers. There is a family of leucistic Trumpeter Swans that sometimes visit the Sanctuary. Their legs and feet that stay yellow into adulthood are a dead giveaway that these birds have leucism! Leucism is also a heritable condition, meaning a bird with leucism may pass it down to their offspring!

The next time you visit the W.K. Kellogg Bird Sanctuary keep an eye out for these rare and beautiful birds!

References:

1. “Leucism.”Merriam-Webster, Merriam-Webster, merriam-webster.com/dictionary/leucism.
2. Actman, Jani. “Albino Animals, Explained.” Albino Animals – Facts and Information, National Geographic, 6 Mar. 2019, www.nationalgeographic.com/animals/reference/albino-animals/