Note, there is a genetic mutation in American crows, that creates white 
patches at the base of the primaries and secondaries.  These patches can be 
pretty extensive.  Such a bird was present a few years back along Folly 
Quarter Rd. in Howard County. and I tried valiantly to make it into an 
exotic species.  A quick check of  the Big Sibley, as well a crow book or 
two ruled out the exotic theory.

Kurt Schwarz
HowCo
goawaybird at comcast dot net