Note to Brad--

I was curious to know if you had your Rufous Hummingbird in the hand (I
think a notched t2 is diagnostic) or if there was some other feature you
were looking at. I find imm. selasphorus to be quite the difficult ID
problem.

Mark Miller

Mark and others:

I may have been hasty on saying the Rufous hummer was an imm., I suppose
it's possible that it was an adult that was re-sprouting a new gorget--but
that's unlikely and the gorget didn't look aberrant. The reason I said that
it was an imm--without thinking much about it--is because the bird had an
all rufous back (an adult male Rufous character), but a streaky gorget. Not
a partial rufous back, not blotchy: totally rufous from rump to crown. Just
the merest bit of green where the wings join the body. I've seen many adult
male Rufous hummers over the years with more green feathers, randomly spread
on its back, than this bird; I looked for random green feathers on the back
and didn't see any, although seeing them is common on male Rufous. I also
know that there have been male Rufous hummers found with totally green backs
(pretty disconcerting, no?). I am unaware of any Allen's ever having been
netted, measured, etc., with a totally rufous back.

Now, why did I blithely say "imm"? The bird had a streaky gorget like an
imm. male rufous--or Allen's. No imm. male Allen's or female Allen's is
going to have an all rufous back (unless some banders have found a few I'm
unaware of, and if so, what are the statistical probabilities?). My
assumption was that the bird had fully molted into adult body feathering,
but that the gorget was late in blooming. I'd be interested to know the
normal sequence of these molts south of the border at this time of year.

By the way, the bird wing-trilled when trying to drive an Anna's out of the
tree tobacco.

Brad