An uncommon pair.
I took this photo of an albino tree swallow along the Niagara River in Gratwick Park in North Tonawanda. This bird was stirring up interest among local birders. Then less than two months later, I spotted another true albino--a mink--in the same small park. What are the odds?
Christopher Kundl, Niagara County
Of all the types of albinism, complete albinos (indicated by having red eyes) are the rarest. With regards to birds, one source states that 1 in 1,800 individuals shows signs of albinism. A 1965 review of albinism in the journal Bird Banding found that only 1 of 7 albino birds were complete albinos. If these figures hold true, the odds of a true albino bird would be about 1 in 12-13 thousand.
Full or true albinos are caused by a genetic mutation that does not allow the animal to produce melanin. That's why the plumage/fur, skin and even the eyes lack pigment. Albino birds rarely live to adulthood: the lack of pigment in the eye negatively affects vision, and the feathers lack the durability that melanin provides, making them more brittle. In addition, all albino animals are easier targets for predators because their white coloring makes them stand out. In the case of the mink, which is a predator, the white coloring would make it hard to sneak up on prey, except on land in winter when there is snow cover.
Director, DEC Five Rivers Environmental Education Center