Date: Mon, 22 Jul 2002 14:15:25 -0700
Reply-To: Sheri Williamson <tzunun@MINDSPRING.COM>
From: BB for Hummingbirds and Gardening for them in the Southeast <HUMNET-L@LISTSERV.LSU.EDU>
Subject: Re: [HUMNET-L] Rufous vs. Allen ID

To the excellent comments that have already been made on this thorny
issue, I would only add the following:

- On an adult male Rufous/Allen's, a back that's more than 50% green,
regardless of the uniformity thereof, is my first cue to begin
considering the possibility of Allen's. With such birds, I only feel
comfortable assigning a bird to one species or the other if I get a
good look at the tail; otherwise, they remain "Rufous/Allen's."

- "Rufous/Allen's" is being used more and more often outside the
hummingbird community as a more precise generic term for this
challenging species pair, while the older and less precise term
"Selasphorus sp." is still perfectly appropriate when Broad-tailed has
not been eliminated from consideration.

Sheri Williamson
Bisbee, AZ
tzunun@mindspring.com
http://tzunun.home.mindspring.com

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Date: Sat, 20 Jul 2002 15:01:30 -0500
Reply-To: BB for Hummingbirds and Gardening for them in the Southeast <HUMNET-L@LISTSERV.LSU.EDU>
From: BB for Hummingbirds and Gardening for them in the Southeast <HUMNET-L@LISTSERV.LSU.EDU>
Subject: Re: [HUMNET-L] Rufous vs. Allen ID

Haji,

At 03:56 AM 7/20/2002 -0700, Haji Warf wrote:

>I thought if you aren't able to detect any green at
>all, it's likely Rufous, whereas Allen's have some
>green intermingled on its back?

Welcome to the greatest hummer ID challenge in North America. If an adult
male Selasphorus has a completely rusty back, it is a Rufous. If an adult
male Selasphorus has a green back with rusty feathers intermingled, it is a
Rufous. If an adult male Selasphorus [not Broad-tailed] has a completely
green back, it is very likely to be an Allen's, but a small percentage of
adult male Rufous have completely green backs, so there is always the
outside chance that a green-backed adult male Selasphorus is not an
Allen's. In my somewhat limited experience with Allen's [almost 50,
including all ages and both sexes] the quality of green on an adult male
Allen's back is darker and more "contrasty" to the rusty parts of the
plumage than green-backed Rufous [a few]. However, this is not the kind of
field mark that I would give to the inexperienced hummer-identifier because
it is somewhat subjective and because I have not had the opportunity to
test this conclusion extensively.

Immature male Selasphorus [not Broad-tailed] with any rusty feathers on
their upper backs are clearly Rufous. All others, [and that would be many
or most this early in the season] should go through a "tail feather test"
to be identified to species.

As for females, I have seen female Selasphorus that I thought to be Allen's
because of their small stature and fairly skimpy tail. And, in most cases
[but not all cases], these birds are identifiable as Allen's once they are
captured and measured. However, I have seen enough female Rufous that were
small that I would not recommend considering an identification absolute
unless the measurements could be taken. Therefore, I would recommend
leaving some Selasphorus identified simply as generic Selasphorus - however
unsatisfying that may be.

NLN

***************************
Nancy L Newfield
Casa Colibrí
Metairie, Louisiana USA
<colibri@webdsi.com>
***************************

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