Wednesday, February 16, 2011

Leucism vs. albinism

Pale Beauty over Fifth Ave. February 13, 2011
photo courtesy of

Yesterday a reader named Laura Peterson sent in a question which I forwarded to John Blakeman. Laura's question and Blakeman's answer are below:
Marie ,
Just finished reading John Blakeman's blog in which he stated that he feels sure that Pale Beauty has leucistic genes. It would be just wonderful to have a pure white red-tailed hawk in Central Park. Question is - can albino hawks survive in the wild since they don't have their original colored feathers.
Laura Peterson

Blakeman replied:


Albino hawks, those without any body pigmentation (which is known but very rare in Red-tails), do have a multitude of physiological and perhaps psychological problems. True albino Red-tailed Hawks seldom survive their first year.
But Pale Beauty is not, and will not become an albino. She has normal pigmentation in all of her organs and tissues, with the exception of the tail feathers. She, properly, has leucistic pigmentation. Leucistic Red-tails are rather well-known, as leucisticism in this species is far more common than in any of the other Buteo hawks such as Red-shouldered Hawks, Broadwinged Hawks, Rough-legged Hawks, or several others. Just why leucisticism is so common in Red-tails is unknown. But clearly, it conveys no survival difficulties. A very white leucistic Red-tail can survive and breed as well as a normally-pigmented adult.
It was originally thought by some ornithological ethologists (bird behavior experts) that the red tail of the Red-tailed Hawk was an important signal of sexual maturity and species identification. But that thought has been negated by the numerous leucistic Red-tails with white tails that have mated (pair-bonded), copulated, incubated, and raised eyasses from normally-colored mates. The question then still remains, why are the tails of this species so prominently colored? There are a few other Buteo species in Africa and South America that also have nearly identical red tails. We don't know the Darwinian origin or function of this tail color in the Buteo species that have it.
Sure is nice to watch, however.
So no, Pale Beauty will not be restricted in any way with the emergance of new white feathers in coming years---should that be the case (and I think there is now a high probability of this).
Thanks for the good question.

--John Blakeman