Date: 10/3/19 9:29 pm
From: Robert O'Brien <baro...>
Subject: [obol] Oregon eBird Tropical Kingbird statistics
Somehow there's a little confusion here. I don't think I said there were
12 _straight_ vocal kingbirds, I said that of about 302 eBird reports there
are a total of 12 reports of calling. That means, to give an
trivial interpretation, there is a 290/302 = 96% allowance that the
remaining observations _could_ have included Couch's Kingbird..
Now, to reiterate, I don't think anyone is claiming a significant fraction
of these _are_ Couch's; I just think that the vast majority of these
sightings were not positively identified, except by expectation and/or
range. I believe this was the intent of the first post on this matter. Now
If anyone wishes to include range/expectation in the ID, I have no problem
with that. The very first Tropical Kingbird I saw in Oregon ~35 years ago,
was very vocal so I'm sitting pretty.

I have gone through the 302 observations more carefully now, searching for
'call', 'twitter' AND 'vocalizing', finding 10 observers who heard the call,
5 observations who said the bird was silent; leaving 284 observations which
did not mention the distinctive call either way. With better accuracy this
pretty much upholds the above (trivial) probability that one or more might
have been a Couch's.

There were four additional mentions of birds giving calls, but they were
due to a party of two observers giving the same observation on the same
date and I've removed them.
I've included the dates this time. (These more careful statistics
supercede my previous post but give pretty much the same conclusion.

Bob OBrien Carver OR Observations below PS
If anything comes out of this at all, birders who don't hear the call
should report that also.

OBSERVATION DATE Calling Vocalizing SPECIES COMMENTS
11/17/14 NO Discovered at small pond along east side of road most of the
way north along east edge of bay. Flying from roadside wires to exposed
perches in low trees up to very tops of highest conifers, often
flycatching. Very similar habitat & behavior to the one I saw at Yaquina
Bay a couple of weeks ago. A kingbird by size, shape, and behavior. Bright
yellow breast and belly, pale grayish head with darker area around eye.
Olive-green back, gray-brown wings and tail. Somewhat heavy blackish bill.
Did not hear it vocalize. Have photos and will post once they are
downloaded....
12/28/14 NO Bird was first spotted on the Cape Arago Highway in Coos Bay at
2:40pm on 28-DEC-2014. During the 10 minutes we had it, it never vocalized
but just flew back and forth between several utility wires and a nearby
Douglas Fir. We lost sight of it about 2:50pm when it flew inland
(east).----TRKI vice WEKI based on deeply notched tail shape and lack of
any tail white (although a worn WEKI could look similar), larger and
thicker bill than a WEKI, distinctly brown wings with very light covert
edges, yellow-green breast extending almost to the throat, and a very green
mantle.
10/05/15 NO First reaction when driving up was oh, scrub jay, due to pale
breasted bird on top perch. But no, Kingbird! Very yellow underneath, large
bill (depth and length), plain brown tail w/o white outer vanes, gray head,
dark auriculars. Many photos. Never vocalized. Viewed from 43.6673,
-124.2037.
11/22/15 NO One at slough just west of machine shop area towards north end
of Wireless. Perched up briefly on powerlines. Noted yellow underparts
grading into grayish-white chin. Long black bill. Gray crown, brownish back
and folded wings. Tertials show bright, light edgings. Tail is brownish,
with slight fork. No vocalizations heard.
11/22/15 NO One at slough just west of machine shop area towards north end
of Wireless. Perched up briefly on powerlines. Noted yellow underparts
grading into grayish-white chin. Long black bill. Gray crown, brownish back
and folded wings. Tertials show bright, light edgings. Tail is brownish,
with slight fork. No vocalizations heard.
11/06/12 Yes One in 8' pine about 15 ft from me along fenceline, the other
at top of a spruce. Both had bright yellow belly and breast, white throat.
Calling between both birds, single note brief trill. Both actively feeding.
These birds have been reported by others at this location during the last
few days.
11/08/12 Yes Reported on OBOL. Hawking insects from low to middle height
perches. Deeply notched dark--brown tail, no white edging. Calls as in
Sibley app.
11/01/13 Yes Photos available upon request (both myself and Tom got some).
This is presumably the same bird that many have been seeing at this
location. Vocalizing freely with characteristic metallic twitter. Obvious
kingbird morphology and behavior, sitting on various treetop perches and
flycatching before returning to perch. Forked tail and long heavy bill and
yellow breast evident.
11/27/13 Yes 1st thought WEKI, but this bird had a forked tail, yellow up
the chest to throat, much yellow underside of wings, no white tail margins,
also it vocalized as we were leaving.. in true TK form.. woohoo
11/05/14 Yes Found today by Janet Lamberson, who told me of it. Thank you,
Janet! About 2 minutes after I stepped out of the car, I heard the
characteristic chittering call of this species. As I jogged toward the
sound, I saw two birds in the air and realized it was the kingbird being
chased by a Sharp-shinned Hawk! The Sharp-shin came within a couple of feet
and just missed. The kingbird escaped and flew about 200 m to a perch atop
a tall conifer and continued chittering. Apparently it was really worked up
(understandably so!) -- and likely had been scolding the hawk in the first
place when I'd initially heard it.
12/13/14 Yes Seen by others previously at this location recently. Watched
it fly from the east into the trees behind the pizza shop calling.
10/02/15 Yes Yellow-bellied Kingbird, much larger bill than western.
Rattling call different than western. Photo.
11/03/15 Yes Heard his trilling call across the pond near the parking lot
first- I was on the northern side opposite. Used my scope to locate him on
roadside wires. Distant view but could detect his yellow breast, large bill
and characteristic kingbird perching style. Wasn't able to relocate when I
returned to parking lot. Seen here previously a couple weeks ago.
11/29/15 Yes Photos plus heard calling giving the zippy trill which we are
very familiar with. Video can be seen at: https://youtu.be/GWvazZS_GZM.
11/20/16 Yes Heard and seen. Twittery call diagnostic (as opposed to the
"pip" of a Couch's). Primaries appeared to be of uneven length which also
suggests Tropical rather than Couch's, which tend to have evenly spaced
primaries (Couch's).--Seen in shrubbery on the south side bank of river
downstream from bridge.

 
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