The White-crowned Sparrow shows a nifty distribution of subspecies (species
??) that I find kind of puzzling. Eastern birds (leucophris) have dark pre-
ocular areas (not quite the lores, but above them) while the western types
(gambelli, pugetensis and nuttalli) have white pre-ocular areas. The puzzling
type is _oriantha_ which is a western bird, but with the dark pre-ocular
areas of the eastern leucophris. I wonder if this subspecies is more closely
related to the eastern one or not? If it is, then the biogeographical pattern
suggests an invasion of eastern birds into the west in the past, after the
western birds had differentiated from the eastern birds. If we assume that
this is the case then it is odd that this eastern type population has not
become infiltrated by western genes, suggesting that there is some type
of barrier between oriantha and the western birds. Alternatively, oriantha
may have split off from the western birds and the eastern leucophris split
off from oriantha. The patterns of subspecies (species?) shown by other
birds like Fox Sparrow suggest that this is not the case.
If the opposite is true and oriantha is more closely related to the western
birds then the possibility comes to mind that the colour of the pre-ocular
area is determined by a simple gene that can flip flop back and forth and
therefore is not important in defining the major split in WCSP lineages.
In any case I find this distribution of white browed versus black-browed
White-crowned Sparrows intriguing. Any other ideas, thoughts out there?

Al Jaramillo
jaramill at sfu.ca
Vancouver, B.C.