Date: 10/15/19 12:55 pm
From: <whoffman...>
Subject: [obol] Re: A note on fall Kingbirds
Hi -

I went to high school in Newport in the late 1960s, and birded the area a lot, than and until 1977, when I moved to Florida. If I had seen a Tropical Kingbird I probably would have called it a Western, but I did not see any fall kingbirds, despite birding areas (e.g. HMSC ) where Tropicals are now annual. Up through the 1960s the coast had a number of bird collectors, notably Alex Walker and Wes Batterson at the end, and others earlier, who would have certainly collected a Tropical Kingbird had they encountered one. In fact, Oregon's first (and for years only) Cassin's Kingbird was collected on the Lane Co. coast.

The bottom line: The annual occurrences of Tropical Kingbirds on the Pacific Northwest coast is a new phenomenon that has developed during Roy Gerig's and my lifetime. It is not something that was missed by generations of birders on the Oregon coast.

The Tropical Kingbird occurrences are generally considered an example of reverse migration, in which some individuals of a migratory species migrate north (here northwest) when the rest of the population is migrating south(east). So evidently something has happened in one or more breeding areas, presumably in Mexico, that has led to this faulty migration. Tropical Kingbirds seem to like agricultural areas, so it may just be that a greatly expanded population in areas growing winter vegetables for the US is generating more mistaken birds. Another possibility, totally speculative, is that agricultural chemicals are interfering with internal orientation and increasing the frequency of reverse migration.

Reverse migration is widely believed to account for some of the occurrences of Fork-tailed Flycatchers (close relatives of kingbirds) in eastern US, but their pattern of occurrence is much older, and predates the development of most agricultural chemicals.

Wayne


From: "Mike Patterson" <celata...>
To: "obol" <obol...>
Sent: Monday, October 14, 2019 7:46:43 PM
Subject: [obol] Re: A note on fall Kingbirds

A few years back, I sorted through Tropical Kingbird records for
Oregon and Washington...

http://www.surfbirds.com/community-blogs/northcoastdiaries/?p=2506

One of the more curious things about my search was the dearth of
records before the mid-1970's, a couple records from Washington
(including specimen records) and nothing official from Oregon.
Roy's note on the treatment of kingbirds by the ruling members
of the birding community of that period may be the explanation.

I did a bit of rooting around in my own personal records and
discovered I have seen 39 Tropical Kingbirds from 24 unique by year
and location records on the Lower Columbia (both sides of the river)
since 2000. 11 of 39 were multiple birds, as many a 3 interacting
together. These were all birds I had reported to either birdnotes,
OBOL or ebird. There are probably a handful more I could find if
I took the time to dig through old notebooks or could search OBOL
records from before 2000.

By contrast I have only seen Western Kingbird in the Spring and
Summer. And I've seen more Tropical Kingbirds on the Lower
Columbia than Eastern Kingbirds, Say's Phoebes, or Ash-throated
Flycatchers.

--
Mike Patterson
Astoria, OR
Lies, Damned Lies and Statistical Significance
http://www.surfbirds.com/community-blogs/northcoastdiaries/?p=3761
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