I have been observing this individual house sparrow coming to my feeders for over 20 months.  I am interested in whether anyone else has been able to follow the longevity of flight feathers using this approach or any other approach.  the literature on how long-lived flight feathers are is sparse and I would be interested in anyone else's approach to studying this interesting developmental question.  The idea that the only way this occurs is by somatic crossing over of a dermal patch of tissue that was originally heterozygous for albinism suggests that two heterozygote parents probably mated to produce this individual.  I have a single sighting of another individual with one tail feather albino suggests that the same or another mating may have produced another such offspring in my neighborhood which also went through the same somatic crossing over to produce an albino feather.  Any discussion of this project is welcome. Here is my iNat project journal record of the individual.