rising@utzoo.uucp (Jim Rising) (05/03/88)
A question was raised earlier about the taxonomic status of the
"Black-tailed" Gnatcatchers. Subsequent to that posting I received
a monograph on these, "Speciation and Geographic Variation in
Black-tailed Gnatchers," Ornith. Monogr. No. 42, A.O.U., by
J. L. Atwood. Atwood presents evidence that the Black-tailed
Gnatchers of SE California and SW Arizona are locally sympatric
with California Gnatcatchers of SW Cal and Baja Cal, but do not
interbreed with them. They also differ morphologically, apparently
have very different songs, and differ electrophoretically. Thus, he
suggests that they be treated as a different species, the California
Gnatcatcher (Polioptila californica), as opposed to the Black-tailed
Gnatcatcher (P. melanura). I suspect that the A.O.U. Check-List
will accept this evidence.
Spring migration is still slow in Toronto, though there are numbers of
Myrtle Warblers in now, and thrashers and bobolinks are back. I hope
that there's a big rush soon!
--Jim Rising
--
Name: Jim Rising
Mail: Dept. Zoology, Univ. Toronto
Toronto, Ontario, Canada M5S 1A1
UUCP: {allegra,ihnp4,linus,decvax}!utzoo!rising