MD Osprey:
While I'm at it ... crossbills are sometimes found in mixed flocks ...
Red Crossbills, as a species, are not reviewable in either
jurisdiction (MD or DC); however, the committee would welcome reports
(especially audio recordings) of any observed "Type 1" or "Type 2"
Red Crossbills as subspecies/forms that are unusual to our region.
With great trepidation, I offer the following link for more information ...
http://research.amnh.org/ornithology/crossbills/
The following message, providing additional related information, was
written in 1998 by Harvey Mudd, who was then the Chair of the MD/DC
Records Committee ...
The current irruption of Red Crossbills into Maryland presents area
birders with an opportunity to help unravel one of the more complex
biological situations in current North American ornithology.
As detailed by Paul DeBenedictis in his article "Red Crossbills, one
through eight" [Birding 27(#6), 494-501, 1995], crossbills have
recently been under intensive study by, among others, Jeffrey Groth
who, in 1993, published a monograph on them ("Evolutionary
Differentiation in Morphology, Vocalizations, and Allozymes among
Nomadic Sibling Species in the North American Red Crossbill": Univ.
of California Publications in Zoology, 127, 1-143, 1993). Charles
Sibley in his computerized "Birds of the World", 1996, mentions that,
in a personal communication Groth had told him he intended to propose
splitting the North American forms of Red Crossbill into 9 species.
At some time in the future, the AOU may accept some or all of these
splits. The policy of the Maryland/District of Columbia Records
Committee (MD/DCRC) is to follow AOU taxonomy. The question will then
arise "Which of these species has been recorded in Maryland and/or
the District of Columbia?" At present, Red Crossbill is not on the
list of species that MD/DCRC seeks to review.
However, rather than await the next crossbill invasion (scheduled for
roughly 20 years from now), MD/DCRC is attempting to get ahead of the
curve by soliciting tapes of the calls of the current invaders. We
will undertake to have sonograms prepared from the tapes in a
centralized, uniform manner, and deposit these sonograms in the
MD/DCRC files for possible future use.
The call types appear to be a major criterion for distinguishing the
Groth-proposed species, and according to DeBenedictis the races
currently recognized in specimens on morphological grounds cannot at
the moment be associated with certainty with call types. Thus, even
study of museum specimens might not permit resolution of the problem
for MD and DC.
Since the opportunity to obtain such tapes may pass us by at any
moment, MD/DCRC urgently requests that observers who tape crossbill
calls in Maryland or DC send the tapes (or high quality copies of the
originals) to Phil Davis (2549 Vale Court, Davidsonville, MD 21035).
If requested, after sonograms have been prepared Phil will return the
original material submitted as well as copies of the sonograms
themselves for the use of the observer in sorting out the "species"
he/she has recorded. If anyone prefers to do the conversion to
sonograms him/herself, he/she should please send copies of the
sonograms directly to Phil, with a notation as to what program was
used for the conversion. For all tapes or sonograms, it would be
most helpful if the observer were to note the exact locality, time,
flock size and even sex ratios, as well as the types of trees in
which the crossbills were feeding and the number (if any) of other
species (i.e. White-winged Crossbills) in the flocks.
To date, we are aware of type 3 and 4 calls having been identified in
Maryland. Tapes of other call types would certainly be of great
interest. However, our aim is to obtain a representative sampling of
the calls from various areas where crossbills are seen or heard in MD
and DC. The help and cooperation of all area birders will be most
appreciated in accomplishing this goal.
Thanks in advance to all who participate.
Harvey Mudd, Chair MDDCRC
P.S. Much additional information about the red crossbill situation
is available at the Internet web site of the American Museum of
Natural History, "Crossbills: audiovisual guide", at:
http://research.amnh.org/ornithology/crossbills
____________________________________
S. Harvey Mudd
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Phil Davis, Secretary
MD/DC Records Committee
2549 Vale Court
Davidsonville, Maryland 21035 USA
301-261-0184
mailto:[log in to unmask]
MD/DCRC Web site: http://www.MDBirds.org/mddcrc/rcindex.html
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