Jack & All,
Flocks of Western Meadowlarks in the Willamette Valley at this time of year are
mostly migrants from east of the mountains. Even locally nesting birds may move
into marginal habitats that they don't use during breeding season.
If you've seen meadowlarks in this same area, paired up with males singing and
females responding with solicitation calls during April, May, and June, then
that would suggest local nesting. However if you're usually seeing them as a
"flock" those might just be migrants that stayed a little longer into spring,
and/or returned in early fall.
I did a good share of the field work for the 2011 nesting territory study that
you linked to. The mean territory size is just an average; that implies some
territories were larger and some were smaller. Smaller territories usually
reflect higher quality foraging habitat with good diversity of native plants
(which tend to support more bugs). As I recall, in the West Eugene Wetlands
some territories on restored prairie were as small as 6 or 8 acres. At Baskett
Slough NWR there are some territories even smaller than that, on the
highest-quality prairie on top of Baskett Butte.
An even more important factor for WEMEs is "landscape scale." Meadowlarks don't
really care if the rest of the neighborhood is ugly industrial land, just so
long as things are mostly open with good lines of sight. In west Eugene a lot
of the territories we mapped were in patches of open space surrounded by
mixed-use industrial/residential development.
Joel
From: Jack Williamson <jack.williamson.jr@xxxxxxxxx>
Date: Sun, 10 Nov 2019 12:23:40 -0800
Subject: [obol] Western Meadowlark: Habitat - How Much is Enough
A persistent flock of eight to ten Western Meadowlark along the Clackamette
Cove and River Access Trail in Oregon City recently sparked my curiosity
about the habitat needs of this species. I usually find meadowlarks
there in an area just three acres in size and less frequently in an
adjacent sparsely covered site of about five acres. It wasn't until my dog
walk yesterday that I began to suspect the flock might be inhabiting the
place year-round. And, I doubt most people viewing the location on Google
Maps would think to search for meadowlark in this isolated, mostly urban,
mixed-use residential and commercial wasteland of sorts . . . .
According to a 2011 study of the Western Meadowlark habitat in the southern
Willamette Valley, the mean habitat size per breeding pair was 14 acres,
which would suggest the Clackamette Cove site might support one pair. So
what's up with the small flock that seems to always be in a location that,
for all useful purposes, is less than 10 acres in size.
--
Joel Geier
Camp Adair area north of Corvallis
