
|
[tn-bird]
||
[Date Prev]
[07-2006 Date Index]
[Date Next]
||
[Thread Prev]
[07-2006 Thread Index]
[Thread Next]
[TN-Bird] Still more on Red Crossbill "cryptic species"
- From: Bill Pulliam <bb551@xxxxxxxxxxxxx>
- To: TN-Bird <tn-bird@xxxxxxxxxxxxx>
- Date: Sat, 8 Jul 2006 19:11:28 -0500
A little more reading, and it appears that the situation in the
southern Appalachians is relatively simple, with primarily two of the
more easily distinguished types here (type 1 and type 2).
Type 2 is the most widespread "species" in the lower 48. It is a
large, heavy-billed form that prefers pines with relatively stout
cones. In Colorado I thought of it as the "Ponderosa Crossbill"
since it especially liked ponderosa pine. Its vocalizations all tend
to be relatively harsh, hoarse, and hard; the flight call is a little
more drawn out than most of the other "species." To my ears, its
flight call gives the impression of dropping in pitch, "kyup kyup
kyup" instead of just "kip kip kip." Overall for this form, think
"big and harsh."
Type 1 is a smaller, lighter-billed form that prefers more delicate
cones like white pine and hemlock. I'm not very familiar with it in
person, but the recordings of its calls indicate that they are
significantly "cleaner" than type 2. The flight call sounds clear,
short, and level in pitch to my ears in comparison to type 2. Think
"small and clear."
The possibility of type 3 here also exists; this is the smallest,
lightest-billed crossbill in North America, and is a hemlock/spruce/
etc. specialist. Its calls seem to have a thin, squeaky quality: not
so harsh as type 2, not clear like type 1. It is also a much smaller
and finer-billed bird than type 2, a difference that should be large
enough to be useful in the field. Think "small and squeaky."
I thought those of you in East TN where crossbills are more often
encountered might find this info useful. There is of course no
guarantee that the AOU will ever actually split these forms; this
split has been discussed for about two decades without actually
happening yet. Even if it does happen, the AOU might split them
along unanticipated lines.
Bill Pulliam
Hohenwald TN
=================NOTES TO SUBSCRIBER=====================
The TN-Bird Net requires you to SIGN YOUR MESSAGE with
first and last name, CITY (TOWN) and state abbreviation.
You are also required to list the COUNTY in which the birds
you report were seen. The actual DATE OF OBSERVATION should
appear in the first paragraph.
_____________________________________________________________
To post to this mailing list, simply send email to:
tn-bird@xxxxxxxxxxxxxx
_____________________________________________________________
To unsubscribe, send email to:
tn-bird-request@xxxxxxxxxxxxx
with 'unsubscribe' in the Subject field.
______________________________________________________________
TN-Bird Net is owned by the Tennessee Ornithological Society
Neither the society(TOS) nor its moderator(s)
endorse the views or opinions expressed
by the members of this discussion group.
Moderator: Wallace Coffey, Bristol, TN
wallace@xxxxxxxxxxxxxxxxxxx
------------------------------
Assistant Moderator Andy Jones
Cleveland, OH
-------------------------------
Assistant Moderator Dave Worley
Rosedale, VA
__________________________________________________________
Visit the Tennessee Ornithological Society
web site at http://www.tnbirds.org
* * * * * * * * * * * * * * * * * * * * * * * * * * * * *
ARCHIVES
TN-Bird Net Archives at http://www.freelists.org/archives/tn-bird/
EXCELLENT MAP RESOURCES
Topographical Maps located at http://topozone.com/find.asp
Tenn.Counties Map at http://www.lib.utexas.edu/maps/states/tennessee3.gif
Aerial photos to complement google maps http://local.live.com
_____________________________________________________________
|

|