Yes, I had overlooked the different migration patterns of eastern birds
in my earlier correspondence. I think Dennis is right in his concept of
studying migrations and classifying species by population
characteristics. Statisticians will always tell you to never infer
beyond your data, and I believe this is what happens when PIF (sorry to
keep pickin' on them, but it's the first group to come to mind) includes
Song Sparrow as a neotrop. It's probably true that a good number of
SOSPs cross the Mexico border, but does that mean Washington's SOSPs ever
even get close? Some populations might never migrate, others might go
1000's of miles.

Perhaps a better assessment would result from determining:

a.) which species have all of their individuals migrating long distances
b.) if the above doesn't apply, nominate geographically (or otherwise)
limited populations (i.e. any discrete subset) that do have long
migrations
c.) determine the severity of the medium which they cross (is it ocean,
desert). Are the habitats which they cross suitable for them?

Thus, a 2-tiered approach to classifying migrants, with of course several
exceptions (which I'm sure will soon be pointed out).

What do you think?

Mike Smith
University of Washington
whimbrel at u.washington.edu