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NC Black-chinned Hummer




My apologies for not posting details on the Biles' hummer sooner.
Unfortunately, this week my husband, and then I, were stricken with the
flu. So until today I have not had the energy nor been in a frame of mind
to compose a lengthy reply to all of you interested in the recently banded
Black-chinned Hummingbird (BCHU).  Those of you that have been to Hampstead
already are aware that last Sunday I sent rather complete details for
Paulette to share with folks (unfamiliar with this particular dilemma) as
they differentiate the Black-chinned from the Ruby-throated Hummingbird
(RTHU) in her yard.  I hope those of you who visit "Ruby" and "Princess"
will spend some time really looking at them. The comparison may seem
daunting for a birder who is not very familair with Black-chinneds, but I
encourage as many of you as possible to take on this opportunity in
Hampstead as a wonderful learning experience.  Having both species in the
same yard should provide folks with the chance to really scrutinize these
hummers and master the finer points of winter hummingbird identification.


Many thanks to Steve Schultz for his rapid response, especially in my
absence.  However, further clarification is in order.  Unfortunately no
field guide that I am aware of outlines the details one needs to look for
when attempting to make a field ID of a female BCHU.  The best reference
material I have seen that deals with separating Black-chinned and
Ruby-throated is available from the Hummer Bird Study Group (written by the
Sargents).  However, be aware that field identification may not be possible
for many birds- in-hand verification of wing measurements may be neccessary
in order to be certain of the bird's identity.  However, there are a number
of 'clues' visible on a perched hummer in good light that should make a
good observer suspicious of whether he/she is looking at female BCHU vs. a
female RTHU.  Most of these characteristics do apply to the bird at the
Biles':

(*NOTE:  If you want to attempt to ID the hummer for yourself with out
assistance, read no futher until you have seen it and made your own notes!)

general shape-  the first thing you will notice is that the BCHU is
shorter-tailed; when it is perched, the folded wing barely extends to the
tip of the tail otherwise it looks a lot like a RTHU

posture- the BCHU sits with her wings slightly drooped when perched (some
BCHU will droop their wings so far that the white feathers on their sides
show through in little tufts against the rear edge of the wing like little
'snowballs')

size- it is a little larger than the RTHU but this may be exagerated if it
is trying to antagonize the RTHU at the feeders as it puffs it's feathers
up in an aggressive territorial posture --or simply when it is cold and
flufs up to retain warmth
        -RTHU: wing chord- 45.49 mm, tail- 23.5 mm
        -BCHU: wing chord- 46.13 mm, tail- 26.0 mm

behavior- it is definitely more aggressive than the RTHU and vocalizes a
good deal;  also it flicks its tail a lot when perched and while feeding
(although RTHUs will tail-flick or pump, they do not do so as constantly as
a BCHU)

(vocalization- this is a very subtle point but if you can compare them, the
BCHU call is softer, lower 'schew' or 'thew' sound)

bill- BCHU 's bill is noticeably decurved (but RTHU's can sometimes have a
decurved bill too and some BCHU have a straight bill as well) and may
appear a bit longer than the RTHU

plumage-  the BCHU shows a definite contrast between back and head color;
the head is mostly a brownish-grey all the way down the nape with only a
couple irridescent feathers; the back is green but a duller, paler green
with fewer irridescent feathers overall than the RTHU; also the throat and
chest are white but the flanks and belly are washed with a greyish-buff and
the combination of these features makes her look like a rather washed-out,
dirty hummer (inspection in the hand confirmed these colors as being true
feather color since RTHUs can look similar, especially in the head, simply
from the accumulation of dirt/sap/pollen  during foraging/nesting activites
or as a result of feather wear)
        -specifically regarding the area behind this BCHU's eye: it is
rather dirty, like the rest of the head, with only a tiny area of pure
white feathers showing close to the eye lid but this is not a definitive
field mark

outermost primary (P10), THE DEFINITIVE FEATURE when taken together with
the above characteristics- the BCHU has a noticeably rounded wingtip,
resulting from wider webs on both sides of the vein near the tip on P10;
the inside web specifically being much wider than that of a RTHU (BCHU may
be >2.5-2.7 mm but most >3.5 mm vs. <2.5mm for RTHU) at its widest point
        -on this BCHU the inside web was 3.9 mm



In regards to the current status of Black-chinned in NC, Harry is, of
course correct.  However, I finally have in my possesion the completed
write-up of the female from Raleigh during the winter of 1997.
Additionally, at the time, John Gerwin and I were able to get both photos
(yes, one does show the rounded P10)  AND sound recordings of that hummer.
Bob Sargent reviewed all of the material last year and agreed weith the
identification.  All of this evidence will be submitted to the NC Records
Committee very shortly.  And, naturally, in the next few weeks I will be
sending my notes, data and photos of the Hampstead BCHU to the Committee as
well.  Therefore, I am confident that the status of this species in our
state will finally become 'official' during 2000.


Susan M. Campbell
Whispering Pines, NC

ncaves@utinet.net