Dear Kelly Cassidy, Roger Craik, and Tweeters:

There seems to have been parallel discussions going on on OBOL
(Oregon Birders On Line) and TWEETERS about dawn songs of swallows,
although the discussion on OBOL was in a somewhat more academic vein.
For the benefit of those of you who don't subscribe to OBOL, you may
be interested in the following message that I posted to OBOL this
morning.

Wayne Weber
Kamloops, B.C.
wayne_weber at bc.sympatico.ca


-----Original Message-----
From: WAYNE WEBER <WAYNE_WEBER at bc.sympatico.ca>
To: Keith Kimmerle <progne at EBICOM.NET>; Multiple recipients of list
OBOL <OBOL at MAIL.ORST.EDU>
Date: Tuesday, June 01, 1999 7:58 AM
Subject: More on night-flying swallows


>Dear OBOLers,
>
> Dawn song (or more accurately, pre-dawn song) in swallows is
>something I have been familiar with for a long time, although I
>haven't particularly studied it. I first became aware of it in
>Violet-green Swallows in Prince George, B.C. in 1964. Violet-greens,
>Tree Swallows, and Purple Martins do it everywhere I have had
>experience with them. Referring especially to Violet-greens, the
>activity seems to peak about 1-1/2 hours before dawn. I disagree with
>others who say it is "totally dark"; if you look carefully, there
will
>usually be a faint glimmer of light in the east. One way of testing
>this would be to see whether this behavior starts later on cloudy
>mornings than on clear mornings.
> My first-ever field experience with Purple Martins was dawn song.
>In June of 1969, while camping at Honeyman State Park, I heard Purple
>Martins calling overhead in the predawn blackness. It was
frustrating,
>hearing a bird that I didn't have on my life list; the calling
stopped
>well before dawn. Finally, one flew over in a feeding foray a couple
>of hours after dawn. Perhaps these birds had wandered over from
>nesting sites on the nearby Siuslaw River, or on Woahink or Siltcoos
>Lakes. (Eric, are there or were there nesting sites known on these
>lakes?).
> In my experience, unlike Keith's, Barn Swallows do not begin to
>sing nearly as early as Violet-green or Tree Swallows (the latter two
>are the earliest components of the "dawn chorus", starting up before
>Robins), and they usually do it from a perch, rather than in flight,
>until it gets lighter. I am unaware of pre-dawn singing in Cliff,
>Bank, or N. Rough-winged Swallows.
> I am surprised how little-known this phenomenon of pre-dawn song
>in swallows seems to be. Perhaps there just aren't too many birders
>afield at 3:30 to 4:00 AM (or earlier, if you happen to live in
Prince
>George).
>
>Wayne Weber
>114-525 Dalgleish Drive
>Kamloops, B.C. V2C 6E4
>Phone: (250) 377-8865
>wayne_weber at bc.sympatico.ca
>
>
>-----Original Message-----
>From: Keith Kimmerle <progne at EBICOM.NET>
>To: Multiple recipients of list OBOL <OBOL at MAIL.ORST.EDU>
>Date: Monday, May 31, 1999 11:09 PM
>Subject: Re: Night-flying Tree Swallows
>
>
>>John,
>>The behavior you are describing sounds like what is referred to as
>>"dawnsong". I believe it was first described in the Purple Martin
>(PUMA)
>>by Gene Morton of the Smithsonian Institution. The behavior is
>common in
>>the Hirundinids as well as some other passerine species such as the
>Eastern
>>Kingbird. Morton advanced the theory that dawnsong evolved as a
>means of
>>early arriving males advertising "available" breeding sites to
>migrating
>>females. Morton went on to speculate that dawnsong was ultimately
>the
>>basis for the evolution of coloniality in the PUMA - attracting
>second year
>>(SY) males specifically so they could cuckold their mates.
>>
>>In PUMAs, the dawnsong is quite loud. Morton stated that a singing
>male
>>martin was able to effectively "project" the song into an
approximate
>100
>>(cubic) mile area. Dawnsong from my experience is considerably
>louder than
>>territorial song sang at a colony site. We have just had Tree
>Swallows
>>(TRES) begin breeding here in Mississippi where I am now at, but I
do
>know
>>that they also dawnsing each morning. My experience has been that
>the Barn
>>Swallows are first to begin pre-dawn singing, followed by TRESs,
>PUMAs, and
>>then kingbirds.
>>
>>I do not know whether Bank, Cliff, or Cave Swallows dawnsing, and
>have not
>>heard Northern Rough-winged Swallows dawnsinging in areas where I
>know they
>>breed (which interestingly, is the only N.A. Hirundinid that has a
>limited
>>vocal repertoire, is not colorful, nor a colonial breeder).
>>
>>So, to answer your questions:
>>
>>- Are they Tree Swallows?
>> If they sounded like TRESs, it is most likely TRESs, as dawnsong
>is
>> a collection of notes from the species' repertoire of song.
>>
>>- Are they feeding? (What are they doing?)
>> Feeding? - no - but the evolutionary significance of Dawnsong is
>not
>> well understood.
>>
>>- Are they using "echo-location" (..., and it seemed like they were
>going
>> a little overboard on the vocalizing)
>> Again - no. The "loudness" of dawnsong supports the theory that
>it's
>> function [was] to attract potential mates during migration.
>>
>>Keith Kimmerle
>>progne at ebicom.net
>>
>>
>>Morton, E. S. 1988a. Dawnsong of the Purple Martin. Atlantic Nat.
38:
>38-48.
>>
>>Morton, E. S. 1989. A purple dawn. Purple Martin Update 2(1): 10-13.
>>
>>Morton, E. S., L. Foreman, and M. Braun. 1990. Extrapair
>fertilizations and
>>the evolution of colonial breeding in Purple Martins. Auk 107:
>275-283.
>>
>
>