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Winter 2003 Chat -- Bachman's and Hermit



Folks:
	I just got the Winter 2003 Chat, the first put out by the new editor,
Kent Fiala. I have some questions to pose to readers, and then some
answers to a different question.

On Page 5, I learned for the first time that
"In the spring of 2000 and 2001 sightings of Bachman's Warbler
(Vermivora bachmanii) were reported from the Congaree Swamp National
Monument in Richland County [SC].  In response to these reports a search
for the bird was made in the spring of 2002 under the aegis of the U.S.
Fish and Wildlife Service ..."

My questions: 1. How many birders, at least those in SC and particularly
in the Columbia area, heard about these "sightings" in 2000 and 2001? 2.
Did you hear about them in time during those spring/summers to go try to
find/confirm the reports? 3. Why, if a report came in 2000, was a
"search" not made of the bird until 2002?

There was no mention of these sightings on carolinabirds (not assuming
that there should be), in N. American Birds, etc. Did people such as
Robin Carter, Caroline Eastman, John Cely, and Lex Glover (all long-time
and very experienced birders from that area) know about the sightings
and make an effort to corroborate? Did one of them make the sightings?

On Page 13, Rebecca Browning comments (correctly) in her nesting Hermit
Thrush paper that "It appears that this species has expanded its range
into the North Carolina mountains fairly recently ..." This is true. She
does later in the paragraph mention whether there had been a lack of
sightings prior to 1979 (first summer report) because of "observers
failing to recognize the rarity of breeding Hermit Thrushes".  Well, she
had the first part right. Lots of birders over the years have combed the
accessible spruce-fir peaks such as Roan Mountain, Grandfather Mountain,
and Mount Mitchell, and there were no Hermit Thrushes there. Eloise
Potter, Tom Haggerty, and I heard and then saw that first singing Hermit
Thrush for the NC/TN mountains at Roan in 1979, and later on there was
some grumblings from the TN folks either that we must have been mistaken
or "how did NC folks beat them" to the first, as they cover the mountain
thoroughly every summer. In addition, people in NC such as Mark Simpson,
and before him Thomas Burleigh, Arthur Stupka, and others, had covered
Mt. Mitchell, the Smokies, etc. very well. They did not see or hear
Hermit Thrushes in the summer.  Thus, the species has moved into the
spruce-fir zone in the past few decades (sure, a few could have been
lurking around some remote spruce-fir patch prior to 1979).

As for WHY the expansion, Browning mentions "perhaps as a result of
recent forest disturbance". I'm not so sure, as I am used to hearing
Hermit Thrushes in Canada and the western states in fairly mature
spruce-fir stands, and I don't think the literture would call the
species a forest disturbance species. Because of mild winters in the
Southeast in the past few decades, the survival of Hermits in winter has
likely been greater than earlier in the last century, perhaps lending to
an increase in the overall population due to winter survival rates. (The
other spotted thrushes all winter in the tropics, where loss of habitat
has probably been more devastating and leading, in part, to overall
population declines.) If there has been a population increase in the
Hermit Thrush in the last 2-3 decades, I could imagine an expansion of
the breeding range, perhaps in all directions, including southward into
NC and TN. That my theory for why Hermit Thrushes are now nesting in
NC/TN -- increased winter survival (and why Swainson's Thrushes haven't
yet shown the same southward expansion).
-- 
Harry LeGrand
NC Natural Heritage Program
DENR   Office of Conservation and Community Affairs
1601 MSC
Raleigh, NC 27699-1601
(919) 715-8697 (work)
FAX: 919-715-3085
e-mail: harry.legrand@ncmail.net