Stuart wrote:

"In South Africa both swallow and common sandpiper (similar to spotted
sandpiper) have started breeding - this is only 6,000 miles outwith their
normal breeding range !!! They do winter there however."

Interesting that he mentions the very examples I could find when I looked
in the literature--probably 20 years ago. I believe Barn Swallows have
been found breeding sparingly in Argentina now, obviously a good example of
this potential. But as Stuart said, this is in their winter range, and
they only have to fail to migrate to form a breeding population. Northern
Parulas have nested successfully in California, as a good example; however,
this never produced a lasting breeding population. This is still a *very
unlikely* event in the bird world, from what we know today.

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