[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Black-chinned Hummer -- details??

I don't want to usurp Susan's chance to respond to this note, but felt that the
need to respond in light of the original e-mail from Mr. LeGrand.
I was fortunate enough to observe the bird in question on 6-7 separate occasions
on the 9th.   Several of these observations were during the time that Susan had
the accompanying Ruby-throat in hand.  2 observations were of fairly lengthy
duration of the perched bird.  The most apparent behavioral characteristic is a
nearly constant and rapid pumping of the tail while the bird is hovering.  This
behavior was noted each time the bird was seen in flight.  On the perched bird
the top of the head and back of the neck appeared to me to be more grey-graphite
in color than the iridescent green associated with a Ruby throat.  The Black
chinned is reputed to have more curvature to the bill than the Ruby throat.
While curvature is apparent in this bird, the accompanying Ruby throat is one of
those individuals with a noticeable curvature in the bill, so this is not as
helpful in distinguishing the two.

Of course to my limited knowledge, the identification of a suspected Black
chinned is typically speculative unless the bird is available for an in hand
observation.  Sort of like the Selasphorus situation where most of the records
are listed to genus and not species; until and unless the bird is in hand to
distinguish a Rufous from an Allen's.  My understanding is that once Paulette's
bird was in hand the structural differences in the wing, specifically the length
of the wing chord and the shape of the first primary flight feather, rather
solidly point to this species of Archilchus.  Of course the observer travelling
to Hampstead will not be able to enjoy such a close inspection, but the
behavioral characteristics should be sufficient to separate the birds.  Plus
Paulette is pretty familiar with Princess by now!

Steve Shultz
Cary, NC

Harry LeGrand <Harry.LeGrand@ncmail.net> on 01/21/2000 08:45:17 AM

To:   "carolinabirds@acpub.duke.edu" <carolinabirds@acpub.duke.edu>
Subject:  Black-chinned Hummer -- details??

Some of us are a bit puzzled over the lack of any details or
descriptions on the female Black-chinned Hummingbird that Susan Campbell
banded in Hampstead last weekend. Have only she, Chris Eley, and the
home owners -- the Biles family -- seen the bird in question?

I'm not asking for a feather by feather description, but what field
marks are folks using to separate the two? There are several reasons for
asking. 1. If other people around the Carolinas have a female
Archilochus at their feeder, a brief comment on the marks might help
them decide if they have something suspiciously "Black-chinned".  2.
Some of us have seen previous female hummingbirds -- such as at Buxton,
Lake Landing, and elsewhere -- that we feel strongly were, indeed,
Black-chinned (but how do you know for sure without a specimen or a
banding record to measure the length and shape of feathers, etc.?).

As the Biles' feeders have supposedly both a female BCH and a female
Ruby-throated, this would be a great comparison, and a great chance for
folks who have seen the birds to let us know any differences in plumage
-- paler or grayer head on BCH?, slightly longer bill on BCH?, more
tail-pumping on BCH, more rounded outer primary on BCH, etc.? (These are
supposed differences.)

The Lake Landing bird (not with any other hummer for comparison) was
noticeably pale headed, with buff or gray feathering on the head, such
that the white spot behind the eye was not sharply separated from the
dark cheek. The head color was clearly not the green color of the back.
The bill seemed very long and slightly decurved. (RTH bill is slightly
decurved, but not noticeably so). I don't recall the tail pumping, but
the bird was clearly different from all the RTH we see in summer, and
the several female RTH that I saw a few weeks ago (and banded) at the
Cape Pines Motel in Buxton. Those birds were dark headed, greenish on
the crown and forehead, with a very sharply demarkated white spot behind
the eye.

The NC Bird Records Committee, of which I am a member, has been leery
about accepting sight reports of female Archilochus, for good reason, as
nearly all references say that it is extremely difficult to be sure
about the ID. But, we'd like to be educated about comparative notes on
the two Hampstead hummers.

You are probably thinking -- why doesn't he just go down to Hampstead
and look at the birds for himself?  I could -- but some of you
supposedly have already been there. Plus, I'm certain I have seen a
female BCH at Lake Landing, and I believe another at Buxton.

Are folks having to ask Paulette Biles "Which one is the BCH?" Let's
hope not! Lets hope folks can figure out which one is the BCH and which
one is the RTH, without having to ask.

Harry LeGrand

Harry E. LeGrand, Jr.
N.C. Natural Heritage Program
Division of Parks and Recreation
1615 MSC
Raleigh, NC 27699-1615

Office: (919) 715-8687
Home: (919) 832-3202
FAX: (919) 715-3085
e-mail: harry.legrand@ncmail.net

The information transmitted is intended only for the person or entity to which
it is addressed and may contain confidential and/or privileged material.  Any
review, retransmission, dissemination or other use of, or taking of any action
in reliance upon, this information by persons or entities other than the
intended recipient is prohibited.   If you received this in error, please
contact the sender and delete the material from any computer.