POWDERMILL NATURE RESERVE
PICTORIAL HIGHLIGHTS
October 9-13, 2002
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Saturday, October 12, 2002:
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Despite more effort and better conditiuons (by
far) for banding, our capture rate today (17.5 birds/100 net hours) actually
was quite a bit lower than yesterday (24.4 birds/100 net hours) when conditions
were much less favorable for banding. Results would have been
considerably poorer were it not for one round at noon when we caught 17
of the 20 kinglets banded today (including all 11 of the Golden-crowned
Kinglets)--most of these were out of one net
set, our Back Field Nets no. 3-6
(four 12m X 2.6m, 30mm nets connected at center pole and arranged at right
angles to one another).
In Ruby-crowned Kinglets,
only the male has a bright, ruby-colored crown, and, although it usually
is entirely concealed, it can be raised dramatically when the male is agitated.
Both sexes of GCKI
, however, have at least some color in their crown, and both often wil
flare their crests during banding (interestingly, RCKI
males almost never do). The female GCKI
(top photos) has a plain yellow crown, while the male (bottom photos) has
a much brighter orange crown bordered with yellow.
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We banded two Northern
(Yellow-shafted)
Flickers
today, including an adult female (top photo) whose multi-generation set
of primary coverts (bottom photo) suggested that she was an after second
year (ASY) bird; furthermore, because the very worn, pale-shafted primary
covert no. 4 on the right wing appeared to be a retained juvenal covert,
she probably is a third year (TY) bird. Here's why:
In general, according to Peter Pyle's (1997)
Identification Guide to North American Birds,
following their first prebasic molt, hatching year (HY) woodpeckers retain
all of their juvenal primary coverts; second year (SY) birds have all juvenal
primary coverts until their second prebasic molt, when they replace up
to several outer juvenal primary coverts. Until the third prebasic
molt, third year (TY) birds (remember, an SY bird on December 31 becomes
a TY bird on January 1) will, therefore, show the two distinct generations
of primary coverts that resulted from the second prebasic molt (i.e., very
worn juvenal inner coverts and fresher second basic outer coverts).
During the third prebasic molt, TY woodpeckers ordinarily will replace
most or all of their primary coverts (in particular, any retained juvenal
coverts will almost always be replaced at this molt). It is only
because the bird banded today happened to retain one juvenal primary covert
(and only on her right wing) that we know she probably is a TY bird.
Otherwise the appearance of her primary coverts, even if they were comprised
of mixed generations of non-juvenal feathers (as was the case on her left
wing), would not have been different from some ATY birds (i.e., a bird
having undergone a fourth or subsequent prebasic molt), and we would have
had to be satisfied with a less precise, ASY, age designation. Simple,
huh? !)
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Friday, October 11, 2002:
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Also among the 15 species today was a new species
for the fall--a hatching year (HY) Yellow-bellied
Sapsucker of unknown sex (the bird, pictured
below, still had mostly brown juvenal head feathering). In
YBSAs,
red crown feathers (just beginning to molt in on the bird banded today)
are not diagnostic for determining sex; it is the color of the throat patch--red
in males and white in females--that differs between the sexes. Today's
YBSA
still had its light brown juvenal throat feathers.
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Wednesday, October 9, 2002:
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Sparrows took the day again on Wednesday, seven
species accounting for half the day's banding total, led by White-throated
Sparrow (42 banded; photo of a bright morph
immature bird below) and Swamp Sparrow
(26).
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Species diversity on Wednesday (37 species) was
the highest since 9/28, and included such notable captures as two Connecticut
Warblers (bringing our fall total to 30),
our third Orange-crowned Warbler,
a late Hooded Warbler
(an adult female that had not quite completed her prebasic molt!), a late
Yellow-bellied
Flycatcher (our first since 9/29), our first
three Golden-crowned Kinglets
of the fall, and, best of all, this adult female Pine
Warbler (top photo by Darlene Madarish).
The bird looks a bit brighter yellow in the second photo than she really
was (however, this was the best photo for comparison with the Yellow-throated
Vireo below it). Although we don't
have much experience with this species (we've banded only 14 others, ten
of these in the fall, and only two of these were adults), we based our
decision that it probably was a female on the fact that it did not appear
bright enough overall for an adult male (in particular, the yellow did
not extend very far along the sides of the bird) and its wing length was
just 70.0mm, which would be very small for an adult male of this species.
Among the species most often confused for an adult
or spring PIWA
is the Yellow-throated Vireo,
and vice versa (photo
below is of a YTVI
banded two weeks ago) Immature PIWAs
in fall are very drably colored and, although challenging to identify,
would not be mistaken for a YTVI.
Note that the YTVI
has a much heavier bill and much more conspicuous yellow "spectacles."
And, although it doesn't show on the picture below, it also has a grayish
rump, while the PIWA's
is greenish.
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