Date: Mon, 11 Mar 2002 22:52:35 -0800
From: Mike Patterson <celata@pacifier.com>
To: HUMNET-L@listserv.lsu.edu
Subject: Re: [HUMNET-L] Rufous "J" dive and shuttle displays

One of the grand mistakes many field guides is the description
of the Rufous display as being oval. The origin of this
description is not clear, but has apparently been passed on from
one field guide to next until recently.

Rufous does a series of j-shaped high dives, one right after
another. Each dive is punctuated by a zuh-zuh-zuh sound generally
believed to be produce by the tail (this may be the function of
the tail notch in r-2). Rufous shuttles are much less grand and
not usually associated with the j-dive.

Allen's does a series of broad, u-shaped sweeps ending in a single
j-dive.

At the Neawanna lek (I don't know what else to call a place where
3 or 4 Rufous males are displaying in an area less than 100m
across with dozens of females around). We get to see all of the
territorial and mating displays made by Rufous Hummingbirds.
I've never seen ovals and I've seen Allen's-like u's.

--
Mike Patterson
Astoria, OR
celata@pacifier.com

http://www.pacifier.com/~mpatters/bird/bird.html

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Date: Tue, 12 Mar 2002 09:03:05 EST
From: Bob Sargent <RubyThroat@AOL.COM>
Reply-To: BB for Hummingbirds and Gardening for them in the Southeast
<HUMNET-L@listserv.lsu.edu>
To: HUMNET-L@listserv.lsu.edu
Subject: Re: [HUMNET-L] Rufous "J" dive and shuttle displays

Miriam, Linda and Humnetters:
If I may comment. These displays by apparent non-breeding hummingbird
species in our area are probably not reliable identification clues (in my
humble opinion). This is not true in all cases, such as Linda's observation,
but I respectfully suggest that great caution should be used when using these
displays to identify a species in our region in the winter. Immature (Second
Year) males and even the shape and size of vegetation in the immediate
display area can greatly alter the shapes of these power dives and shuttle
displays.

In Ruby-throated, immature males as well as females of all ages may do the
diving aggression displays (more of those dreaded personal observations).

Having observed many hundreds of displays from what appeared to be "adult
male" Calliopes in Montana in May, I found them greatly variable in both
height and in the extent of the zig-zag "wash out phase" at the bottom end of
the dives.

Thanks guys for sharing your observations with all of us on Humnet. Neato!!

Bob Sargent
Trussville, Alabama

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Date: Tue, 12 Mar 2002 09:58:10 -0700
From: Sheri Williamson <tzunun@MINDSPRING.COM>
To: HUMNET-L@listserv.lsu.edu
Subject: Re: [HUMNET-L] Rufous "J" dive and shuttle displays

I'll "third" Bob's cautionary remarks. Behavior is a plastic thing,
and even a relatively hard-wired behavior such as the display flight
pattern is bound to be affected by experience and even the
circumstances under which it's performed. All too often, someone's
interpretation of a limited sample of observations becomes THE TRUTH
just because it gets published in a scientific journal, and any
subsequent observations that differ from the published standard are
regarded as flawed or fabricated. Don't buy into either side of this
nonsense! The value of Linda's (and many other Humnetters')
observations is not so much in identification as in broadening our
understanding of these behaviors and their variability. I hope
everyone who has an opportunity to observe male displays, whether in
the wintering or breeding grounds, will make notes on what they see to
share with the rest of us.

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