>We had a Greater Yellowlegs at False Bay on San Juan Island on 11 June;
>was this more likely to be an early fall migrant or an oversummering bird?
>
>David Wright
>dwright at u.washington.edu

I wouldn't be entirely surprised if it were a fall migrant. I saw one on
10 June on Dodson Road last year, where none had been seen on previous
visits. Obviously, it will always be difficult to say for sure. There are
probably small numbers of birds out of range but moving around for some
reason, so they contribute to anomalous out-of-season records.

I think it is commonplace for shorebirds to begin their southbound
migration if their nest fails due to predation. Thus, in a species that
nests in the boreal forest and migrates fairly early, like a Greater
Yellowlegs, a nest may be initiated in early or mid May and fail a few days
later. It takes a while for the bird to get down here, although maybe not
even that long, as GRYE breed in southern BC. It would be interesting to
plot average arrival dates against latitude of the southern edge of
breeding populations.

Dennis Paulson, Director phone: (206) 756-3798
Slater Museum of Natural History fax: (206) 756-3352
University of Puget Sound e-mail: dpaulson at ups.edu
Tacoma, WA 98416