Rob,
I don't have a large number of chickadees at my feeder, but yesterday I
had the two species sitting on opposite sides of my bird bath. They
showed the clear differences between the species. I don't have a good
estimate of how many on the chickadees in our backyard are BCCH this fall.
I have seen some in the past but not every winter.
Clair Mellinger
--
2926 Koffee Lane
Harrisonburg, VA 22801
540 433-1752
mellinac@xxxxxxx
Black-capped Chickadees continue to appear in large numbers in
north-western
Virginia (Frederick, Warren, Clarke, Page, and Shenandoah Counties). Some
feeders appear to have up to a 50% ratio of Carolina to Black-capped. This
may be the biggest push south since I have been studying them in this area
(1974 to present). The feeders we are surveying are ones that in most
years
only have Carolina Chickadees. I have not had time to make a detailed
analysis of the subspecies but most if not all of the ones I have observed
have been the northern race and not our high elevation Appalachian race. I
have had several people ask about the identification of them with some
thinking that they are very difficult to tell apart. Rather than answer
individuals I will give a bulk answer as it appears there are many
beginning
birders who might struggle with this duo. There is quite a bit of
misinformation about them, including a statement (in Birdwatchers Digest I
believe) that the two species never flock together. The very bright
northern
race of the BCCH is quite different from our CACH. The easy mark is the
white
hockey stick shaped mark on the wing of the more northern BCCH. The flight
feathers are heavily edged in white (the stick handle) while the heavily
white edged wing coverts make up the blade. As a former Canadian hockey
player who is going in for hockey related shoulder surgery tomorrow, I
know
the mark well. CACHs may have gray to whitish gray edged flight feathers
but
they lack the distinct edging on the greater coverts. A backwards view
gives
a very distinct white V on the back of a BCCH. Another good mark that is
rarely mentioned is the face of the BCCH is very white from the front to
back
of the face and it contrasts strongly with the relatively light gray back.
The CACH is more dingy at the back of the face and blends into the gray
brownish tinged back. It is not clear cut, distinct and contrasty. There
are
other marks listed in the various field guides referring to size, bib,
song
etc. that are useful. To a beginning birder, who may not have a good
handle
on bird song identification the slower lower song may not be as useful as
visual marks. In the 1970's I did some chickadee interaction studies with
color marked individuals to see if there were any behavior patterns that
stood out. The college students quickly were able to pick out the two
species, even at 100 feet in a net without binoculars. Even three 6-8 year
old children were doing 100% identification after a little practice - so
don't give up. Keep an eye out for the BCCH and I would like to hear how
frequent they are in various parts of the state. It would be interesting
to
hear about the interaction of our resident high altitude BCCH with the
northern BCCH visitors (Highland County feeders comes to mind). If you are
interested I can help with separating the two BCCH subspecies in the
field.
Our Northern Shenandoah Valley CBC will be Dec 15, 2007 - if you wish to
join
us please reply offline: rsimpson@xxxxxxxx
- Rob Simpson
Robert C. Simpson
Associate Professor of Natural Resources
Program Contact for Natural Resources Focus in the Science Degree
Program Contact for Outdoor and Nature Photography Careers Certificate
Contact for information on: Field Biology, General Ecology, Wildlife and
Fisheries, Habitat and Food Plant Identification, Special Studies in
Wildlife
Field Techniques, Birds, Mammals, Reptiles, Amphibians, Fish, Mushrooms
Edible and Otherwise, Plants and Nature Photography.
Email: rsimpson@xxxxxxxx
Course websites: http://www.lfcc.edu/classes/simpson/
Phone: 540 868 7206
Fax: 540 868 7100
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