Alvaro Jaramillo wrote:

>The new population of Barn
>Swallows in Argentina would be a great place to study this type of event,
>but nearly nothing is known about these birds. It is not impossible that
>these are actually not Barn Swallows, but an African species of swallow that
>has colonized Argentina. As far as I know there are no photos, or specimens
>of birds from this population, so their identification is up in the air as
>far as I am concerned. In any case, productivity, mortality, and all these
>ecological parameters could be calculated from a study on this Argentine
>population of swallows and used to address the question of why Barn Swallows
>don't usually breed in Argentina, or why it has made sense for this
>population to try it out.

To add to Al's great discussion of this matter, I'd like to point out that
even if Barn Swallows originating in North America *were* nesting in
Argentina, they would probably be birds that had become residents. We
don't think they would migrate back and forth and nest at both ends of
their route.

>Apparently Common Sandpiper (a European breeder)
>has recently been found breeding in southern Africa, is that right Dennis?

The only two books I have on birds of southern Africa (1984, 1992) don't
list Common Sandpiper as a breeder. "Common summer resident" indicates
presence in the northern-hemisphere winter. One book says "few all year,"
but that surely refers to the nonmigrating immature individuals well known
among shorebirds.

Common Sandpiper *did* breed in Kenya and Uganda (one record each) quite
early in the century but does so no more (according to a 1980 Kenya
check-list). That book states "no further evidence in support of these
early observations has come to light anywhere in Africa, despite the amount
of ornithological investigation in recent decades." The comprehensive
Birds of Africa, Vol. 2 (1986), paraphrases the same statement. I wouldn't
be surprised if these records, one of them from 1911, were the source of
all the "common wisdom" that COSA breeds in S. Africa.

I don't know if there is any newer news than this.

I thought I had recalled something about Barn Swallows breeding in South
Africa, but Vol. 4 of Birds of Africa (1992) makes no mention of this.

Thus there isn't much evidence for long-distance migrants breeding at
either end of their route.

There is (only circumstantial) evidence for Phainopeplas breeding in
southern Arizona, then migrating to the coast of California and breeding
again during the same year. The optimal seasons for Phainopepla breeding
at these two *not-very-distant* areas are at quite different times, so a
bird being able to take advantage of this would have a unique opportunity.
If this in fact does happen with Phainopeplas, it's the only example of
such a phenomenon known to me.

We had this discussion quite a few months previous, actually. Someone
might want to go back through the files to see if we had any further wisdom
(or if we even agreed with what we're writing now)!

Dennis Paulson 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