Hi Lee and Tweets,

I was at the entrance to the Quilomene on Friday of last week and likely saw
the same bird performing this flight display right next to the small parking
area. I looked it up in Birds of North America Online and found the
following:

http://bna.birds.cornell.edu/bna/species/463/articles/behavior

*Courtship Displays and Mate-Guarding.* From Gooding
1970<http://bna.birds.cornell.edu/bna/species/463/articles/species/463/biblio/bib038>,
except as noted. In what is assumed to be a territory-establishment and
courtship display, males fly in undulating circles low over sagebrush?up to
10 consecutive circles before landing (TDR). Undulating Flights also may be
made in a sinuous, but generally straight, flight between 2 perches or
performed in large ellipses or figure eights. Height of undulations may be
up to about 8 m from the ground, with low points dipping below tops of
sagebrush plants. In nearly 11 h, 1 bird performed 42 of these flights
during territory establishment. Birds typically end on a perch different
from the one where they began. This display is generally accompanied by
song.

Upon alighting on a perch at end of Undulating Flight, bird typically raises
one or both wings and flutters them for up to several seconds while
continuing to sing in what Rich
(1980a<http://bna.birds.cornell.edu/bna/species/463/articles/species/463/biblio/bib090>)
termed a Bilateral Wing Display (Fig.
3<http://bna.birds.cornell.edu/bna/species/463/articles/species/463/galleries/figures/figure-3>;
see also Hoffman
1927<http://bna.birds.cornell.edu/bna/species/463/articles/species/463/biblio/bib043>
, Gooding 1970<http://bna.birds.cornell.edu/bna/species/463/articles/species/463/biblio/bib038>).
Bilateral Wing Displays are given at the end of Undulating Flights and often
during song bout or when bird changes its cardinal orientation while on a
song perch. Length and intensity of the display vary along a continuous
gradient. This display may be a ritualized balancing movement (Rich
1980a<http://bna.birds.cornell.edu/bna/species/463/articles/species/463/biblio/bib090>).
It seems likely the Bilateral Wing Display also functions in agonistic
encounters because >2 adults sometimes are in close proximity during these
display bouts.

Both Undulating Flights and Bilateral Wing Displays cease along with end of
song period, presumably upon nest-building and egg-laying. These displays
are only rarely seen, and only at low intensities, during renesting attempts
or attempts at second nests later in season (TDR), suggesting that their
role is largely one of courtship. Gooding
(1970<http://bna.birds.cornell.edu/bna/species/463/articles/species/463/biblio/bib038>)
observed 20 Undulating Flights around a sagebrush holding a second bird,
presumably a female, that perched quietly in lower part of plant. Gooding (
1970<http://bna.birds.cornell.edu/bna/species/463/articles/species/463/biblio/bib038>)
also believed this display is primarily for courtship and secondarily for
territory establishment and maintenance.
And the rest of my eBird checklist for my time there on Friday, May 14 at
7:55am (for 58 minutes):

1 Dusky Flycatcher

1 Common Raven

5 Mountain Bluebird

5 Sage Thrasher

1 Orange-crowned Warbler

1 Nashville Warbler

1 Yellow-rumped Warbler

1 Spotted Towhee

1 Chipping Sparrow

11 Brewer's Sparrow

1 Vesper Sparrow

2 Sage Sparrow

2 Savannah Sparrow

1 White-crowned Sparrow

3 House Finch
1 House Sparrow

--
Adam Sedgley
S e a t t l e, WA
sedge.thrasher [at] gmail [dot] com


On Sun, May 16, 2010 at 10:00 PM, Lee Rentz <lee at leerentz.com> wrote:

> On Saturday Karen and I hiked at DNR's Whiskey Dick Wildlife Area, after
> visiting the Wild Horse Wind Farm owned by Puget Sound Energy. In addition
> to seeing Hedgehog Cactus and and perhaps a score of other wildflowers in
> bloom in the shrub-steppe, we enjoyed several fine encounters with birds.
>
> Sage Thrashers were in courtship mode, and we observed this behavior for
> the first time. After singing long and loud and varied from a sagebrush
> perch, a male would take off on a crazy flight, back and forth for short
> distances, low over the sagebrush. Upon alighting on another bush or a
> fencepost, he would angle his wings steeply up for a couple of seconds in a
> display.
>
> There were six Common Ravens interacting in the air. They would sometimes
> fly as a group; other times splitting off into pairs. Their flight was
> acrobatic, with a lot of wheeling and diving steeply toward the rocks below,
> and filled with raven shouts. It was a seemingly joyous display for perhaps
> five minutes, then they flew off as a loose group. I would appreciate any
> insights that fellow birders might have into this behavior: Was it
> pair-bonding, family play, or something else? How would a scientist
> describe it?
>
> Finally, there were two pairs of Mountain Bluebirds hanging out and feeding
> near a pair of nest boxes. That breathtaking blue of the males is one of
> the visual joys of western birding!
>
> Lee Rentz
> Shelton, WA
> lee at leerentz.com
> _______________________________________________
> Tweeters mailing list
> Tweeters at u.washington.edu
> http://mailman2.u.washington.edu/mailman/listinfo/tweeters
>
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