So are we missing some terminology to use in reference to migratory birds which utilize areas not suitable for breeding but at the same latitudes as their breeding areas, in the weeks or months prior to their migration south? I'm thinking of things like the Black-headed Grosbeak that started this whole discussion (where they never breed in the neighborhood, but show up there late each summer) or the pugetensis White-crowned Sparrows which move into Marymoor Park (where they don't breed) during August/September, prior to their migration southward?

== Michael Hobbs
== Kirkland, WA
== http://www.marymoor.org/birding.htm
== http://www.marymoor.org/BirdBlog.htm
== birdmarymoor at verizon.net
----- Original Message -----
From: Steven Mlodinow
To: Tweeters at u.washington.edu
Sent: Wednesday, August 26, 2009 11:42 AM
Subject: [Tweeters] dispersal


Greetings All

One last point, sorry.
I don't think that local movements of young birds would be considered dispersal. I mean, to take that to an extreme, leaving the nest for the next tree could be considered dispersal. I don't know exactly where the lines are drawn, but I think that the bird would have to leave its immediate environs.

A good example would be the uphill movement of Rufous Humms. I don't know whether this is considered part of their migration or a post-breeding dispersal/migration, but that is the magnitude of movement that I think is required for either dispersal or migration to be used.

Best Wishes
Steven Mlodinow


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