Leucism, a genetic condition found in birds, is relatively uncommon but not extremely rare. It leads to a partial loss of pigmentation in feathers, resulting in birds displaying white, pale, or patchy coloration. An example of this is the American Robin shown below, which exhibits white patches due to leucism.

In contrast to the more prevalent condition of Albinism, which causes a complete absence of melanin and red eyes (as depicted below), birds affected by leucism may retain some color in their eyes, bills, and legs.

While leucistic birds are not as abundant as their fully pigmented counterparts, they are still regularly observed in various bird species, including sparrows, jays, crows, and raptors.