In article <uYGdnYbh2beAE-_VnZ2dnUVZ_tPinZ2d@[EMAIL PROTECTED]
>,
"Von Fourche" <kho****ong@[EMAIL PROTECTED]
> wrote:
> One of the pictures has you with what looks like a magnifying glass
> looking at the bill to see if it's a young bird. Now, if you need a
> magnifying glass, how in the world does a newbie like me learn to
identify
> hummers in my back yard!
No one said it was easy! Imagine if you lived in southeastern Arizona,
with up to 12 species in your yard in late summer. The field marks
separating some of the females and immatures can be pretty subtle, and
even the experts qualify their guesses with "probably."
In banding, there's no room for error, so we use magnifiers and
calipers, because we can. There are other clues for Ruby-throated that
don't require inspecting the bird in-hand, but they're not 100% reliable
so banders don't use them except as corroborative evidence. They're fine
for recreational birding, though. Immature birds' green contour feathers
typically have buff or light gray edges that produce a "fish scale"
effect until their first molt in winter. If you can see inside the
bird's mouth, look for bright yellow. Very young hummers have yellow
"lips" like other baby birds, and short, stubby bills and tails for the
first few weeks out of the nest. Most immature males have a
5-o'clock-shadow appearance in the throat: rows of dark dots. But some
females have rows of lighter dots, so there's a judgment call, and some
immatures of both ***es display clear white throats until they migrate.
The tip shape of the sixth wing primary is a good clue to age and ***,
but it's not easy to see in the field. Finally, any Ruby-throated with
even one iridescent red feather is 99.9% certain to be a male (in 2,000
in-hand birds, I've only seen two females with red feathers in the
throat).
The upside to all this vagary: you can declare a bird's age and *** with
apparent confidence, and no one will be able to argue effectively
against your guess! :-)
--
Lanny Chambers
St. Louis, MO
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