Brian Schmidt of the Burke Museum, to whom I forwarded some albino
chickadee material, had this to say:

"I have one question. How can feathers turn colors after they have
already grown? I am sure you have noticed that museum specimens of 100+
years do not turn white and they have been without proper nutrition.
(It's hard to forage when you're stuck in a museum tray!) Aren't grown
feathers composed of "dead" tissue? How could nutrition/poor health
possibly influence the state of inactive tissue? Either I don't have my
facts straight, or these color changes are the result of some
environmental factor (wear and tear, UV radiation, cage cleaner,
something on the seeds, etc...)."

Good point.....and also relevant for David Wilbur's comments of new
feathers apparently replacing the white ones on his partial albino.
Remember, feathers normally change color only because an old feather is
replaced by a new feather during molt--they don't change color themselves.
And these birds don't normally molt during midwinter. So I would *not*
expect the albinistic birds to gradually become "normal" during the winter
or spring.


Dennis Paulson phone: (206) 756-3798
Slater Museum of Natural History fax: (206) 756-3352
University of Puget Sound email: dpaulson at ups.edu
Tacoma, WA 98416