>
> Roger, what kind of evidence do you have for this? Photos? Measurements?
> Hopefully both? I'd be very interested in learning more about this. The
> only hybrids mentioned for this family in the primary reference on North
> American bird hybrids (Cockrum, E. L. 1952. A check-list and bibliography
> of hybrid birds in North America north of Mexico. Wilson Bull. 64:
> 140-159) are between Common and Hoary redpolls, Common Redpoll and Pine
> Siskin, and Pine Grosbeak and Purple Finch (!!!!). A Red Crossbill x Pine
> Siskin hybrid was collected in North Dakota and reported by Dan Tallman
> some years ago. There may well be others in Eurasia. No Purple X
> Cassin's, which presumably would be somewhat difficult to detect, and it
> will be exciting if you can document such birds. Do you capture them
> regularly enough so that someone might be able to take a blood sample?

This brings up an interesting concept. Do birds that look alike have low
rates of hybridization or is it impossible to tell? For example, I imagine
that the number of Tufted Duck X Scaup hybrids is much higher than the
number of Lesser X Greater Scaup hybrids in the literature. Are there any
know hybirds of Empidonax flycatchers? Do dowitchers hybridize? Are we
just missing these hard to identify hybrids or are they actually very
rare? Any ideas? My gut feeling is that they are actually rare. On the
other hand, meadowlark hybrids are know.

Al Jaramillo
Vancouver, B.C.
jaramill at sfu.ca