In response to Al Jaramillo's observations about white-breasted nuthatches,
western ones differ from eastern ones in wing (tertial & covert) markings
and in apparently averaging a more slender bill, with less arched culmen
(bill difference needs confirmation; we only have a single eatern w-b
nuthatch in the collection). Otherwise no morphological/color differences.
But I too recall being surprised by what they sounded like out here after
knowing them from the east; I have no idea what the call variation is
across the wide range of the species.

We need tape recordings of birds taken and filed in the same way the birds
themselves are saved in museum collections; the Library of Natural Sounds
at Cornell University's Laboratory of Ornithology is attempting to do this,
but I imagine there are lots of gaps. It's high time that the LOO put out
lists of needed recordings from North America, like researchers do for
specimens.

It's more complex than it is simple, I imagine. Anyone who learned towhee
sounds in New York and then moved to Florida would have little doubt that
the southeastern towhees were separate species, as you might conclude about
towhees when you come out here. And I wouldn't be surprised if "spotted"
towhees varied across the west just like "red-eyed" towhees do in the east.
Vocalizations vary geographically just like the birds themselves do, and
analyses of these are long overdue for many common species. There is also
plenty of variation *within* populations that no one would suggest involved
more than one species, but when you get the kinds of differences that
characterize eastern and western towhees, eastern and western marsh wrens,
and maybe even eastern and western w-b nuthatches, it's time to take a
second look.

Dennis "watch out for those ticks, they carry Lyme disease" Paulson