Date: 5/3/20 12:38 pm
From: Michael Gamble (via carolinabirds Mailing List) <carolinabirds...>
Subject: Re: Wake County Swainson's Warblers

I am unfamiliar with the area that these Swainson's warblers were seen but
I can give some information based on my years of field experience with
warblers. I ran a spring migration banding station in Louisiana where we
had 5 male Swainson's warblers on territory at my site. They were all
within 75 yards or less of each other and they would sometimes chase each
other, but most of the time they would just countersing with each other.
Based on Swainson's warblers we repeatedly caught, there were at least 8
males on territory within 100 yards. It's not true that highly territorial
warbler species will not be seen together.

I've also worked extensively with golden-cheeked warblers (another highly
territorial warbler species) in central Texas for the last 5 years. My main
fieldwork was territory monitoring, target netting, and color banding
individuals. Depending on the quality and availability of good habitat, you
can have several golden-cheeked warbler males within what you would think
could be one birds' territory. We would also have areas with multiple
territories that would overlap and the males would not drive each other
off. They will usually just countersing with one another on their territory
boundaries without actually chasing them away (this could be as close as 10
meters apart). They sometimes will fight and chase each other off if one
gets too close but then they will return to their territories and
countersing close by. There are also some males that aren't as aggressive
and will only countersing. When target netting, there are males we play
playback under and they never respond throughout the whole season so not
all males will react to another male singing nearby.

Just thought I'd provide some additional information.

Michael Gamble
Charleston, SC

On Sat, May 2, 2020, 7:59 PM Harry LeGrand <carolinabirds...> wrote:

> I am seeing a few reports on eBird of TWO Swainson's Warblers singing
> along the Neuse today. I was there this morning, hearing and seeing the
> SINGLE singing bird as our group headed downriver around 745, and again
> just the one bird coming back around 1030. The other bird singing at
> bridges 288 and 289 is a Louisiana Waterthrush, not a second Swainson's.
> (I note a few of these lists don't even list Louisiana Waterthrush; today,
> there were about 4-5 singing LA Waterthrushes along the greenway for about
> 2 miles downriver of the parking lot; but just one Swainson's Warbler.)
> Swainson's Warbler are very strongly territorial and charge a song of
> another bird, as witnessed by the many times over the years I and others
> have played tapes. So, if there ever were a second singing bird within
> hearing range of another, one would have driven off the other
> immediately. One Swainson's is seldom if ever going to be within hearing
> range of another, at least certainly not within about 75-100 yards, as in
> the case here.
> So -- eBird editors, there is/was only ONE singing Swainson's Warbler
> along this trail today (May 2). Of course, there could be a female nearby,
> but there are not TWO singing birds within earshot of each other. That
> probably also applies to yesterday's report of 2 singing birds as well.
> But -- yes, there IS indeed a Swainson's Warbler there, singing very close
> to the greenway trail, and you might well be able to see him without the
> use of a tape. He is clearly on territory. Thanks to Eddie Owens for
> finding and reporting the bird yesterday.
> Harry LeGrand
> Raleigh
> On Fri, May 1, 2020 at 9:22 AM Eddie Owens <carolinabirds...> wrote:
>> I did some early morning birding before work, visiting in the
>> southeastern part of the county, parking at Mial Plantation Rd parking lot
>> (it's an eBird hotspot), and hiking to the Johnston Co. line. My target
>> bird was Swainson's Warbler. eBird tools indicated this might be a good
>> place and time for that bird.
>> I encountered at least two birds, possibly a third one (but it was so far
>> up a tributary in the woods, I couldn't hear it well). Location details for
>> the birds are in my report:
>> <;!!OToaGQ!-mznbKP2xAzBLbNmosCLV60OlsXfMWcUIG_PweCzBdS1qOnoTBgJkBIBKdAPgKBmEm8$>.
>> I think they might hang around for a day or two.
>> Happy Birding,
>> Eddie Owens
>> Cary, NC

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