American Hummingbird ID query

To: "'Reg Clark'" <>, "'David Stowe'" <>
Subject: American Hummingbird ID query
From: "James F. Holmes" <>
Date: Fri, 15 Jun 2007 19:43:17 -0700
I took a quick look at the photos of the USA hummingbird that have recently
been circulated on this list.  Although, I am no hummingbird expert, I do
live in california and regularly have Anna's at my feeder. 

It was photographed on a nest (only the female), reportedly in California.
>From initial impression, it appears to be either an Archilochus or Calypte
hummingbird.  The Selasphorous species (Allen's, Rufous, and Broad-tailed
are easily ruled out by the coloration (actually the lack of rufous
coloration).  The large hummingbirds (Blue-throated and Magnificent) are
structurally and plumage much different than this bird.  Ruby-throated
hummingbird (an Archilochus species) is ruled out by range (it has only been
recorded in California a few times and certainly has never nested).  

This leaves, Black-chinned, Anna's, and Costa's Hummingbirds as possible

The structure of the nest immediately rules out Black-chinned Hummingbird
(which makes a very smooth nest without the lichen type objects).  Thus,
Anna's and Costa's are left. These can be difficult to separate and voice is
best. Since this bird has obviously nested in a developed area, I would lean
to Anna's Hummingbird which is common in developed areas.  Costa's is much
more of a desert species but I can't tell from the photo if this is a
California desert community.   

Plumage characteristics are confusing in this bird. 

Anna's has a long tail such that the wing tips fall short of the tail.  At
least one photo suggests the wing tips extend to the tail but not beyond.
The photo of the bird in the nest suggest that the wing tips stop before the
tail.  In Costa's Hummingbird, the tail is short such that the wing tips
extend beyond the tail.  The photos would suggest Anna's based on this

The wing structure can aid in identification.  In Anna's, the inner
primaries are the same width as the outer primaries.  In Costa's, the inner
primaries are about half the width of the outer primaries.  The photo of the
young birds clearly demonstrates that the outer primaries are much wider
that the inner primaries.  Assuming that primary width of a juvenile Anna's
is the same as in adult, the primary photos strongly suggest Costa's.  This
field mark has been questioned by some.

Anna's is a very gray hummingbird on the throat and chest.  Costa's tends to
be much whiter (especially on the belly).  Based on the grayish coloration
on the throat and chest, I would strongly expect Anna's.

I would guess Anna's Hummingbird.  However, the clearest field mark is the
width of the primaries in the young birds which supports Costa's.  It would
help if we knew where in California this was taken. 

Jim Holmes
Sacrament, CA  USA

-----Original Message-----
 On Behalf Of Reg Clark
Sent: Friday, June 15, 2007 6:35 PM
To: David Stowe
Cc: birding aus
Subject: American Hummingbird ID query

Hello David,

How about Anna's Hummingbird . My guess!!.

Reg Clark
Belrose , NSW.

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