We used to have a couple of additional montane CBCs, most recently Santiam
Pass. There is talk of starting one in the Diamond Lake region. It would be
nice to have one in the Anthony Lakes region for comparison.
High-elevation CBCs are not easy to run owing to access issues and few
observers. This may well be a situation in which Doug’s point about the utility
of eBird could be focused on a specific issue. Perhaps ask Oregon birders to
specifically focus on montane areas in February and post to eBird or share with
someone who would?
Alan Contreras
acontrer56@xxxxxxxxx
Eugene, Oregon
www.alanlcontreras.com
http://osupress.oregonstate.edu/book/edge-of-awe
On Jan 6, 2019, at 6:26 AM, clearwater@xxxxxxxx wrote:
Hi Wayne & All,
Thanks for the suggestion, If that were the case, I suppose we should see
higher numbers on more northern CBCs (so far as they extend), and at more
northern eBird observation points (so far as they go).
Looking at eBird, observations farther north into Washington and British
Columbia still seem scant (apart from a couple of feeder-watchers who seem to
be reporting the same flocks of 15-30 birds repeatedly).
Perhaps elevational movement is part of the story. We have so few CBCs in the
mountains, and eBird coverage of mountain forests also becomes very scant in
winter.
Last evening, Paul Adamus mentioned to me that some Canadian biologists are
concerned about Evening Grosbeaks, in part due to their tendency to forage
for grit along gravel roads, and then be killed by passing trucks.
The CBC database does show a steep decline for this species in western
regions (about 8% per year in the Northern Pacific Rainforest region, and 9%
per year in the Great Basin). That could perhaps be accounted for, in part,
by Evening Grosbeaks staying longer farther north or at higher elevations
where there is less CBC coverage. I don't know whether or how the CBC
analysts have weighted geographic coverage in their analysis. But taken at
face value, those are worrisome trends.
Joel
From: "Wayne Hoffman" <whoffman@xxxxxxxx>
To: "clearwater" <clearwater@xxxxxxxx>, obol@xxxxxxxxxxxxx
Sent: Sunday, January 6, 2019 5:19:52 AM
Subject: Re: [obol] Evening Grosbeaks
Hi-
My first thought is maybe they are staying farther north, longer into the
winter?
Wayne
On 1/6/2019 12:37:19 AM, clearwater@xxxxxxxx <clearwater@xxxxxxxx> wrote:
Today's lonely Evening Grosbeak got me wondering ...
I haven't seen all of the numbers from this winter's CBCs yet, but the
pattern of very low Evening Grosbeak numbers in the past two winters seems to
be continuing into this winter.
In 2016-17 only 3 (three) were recorded on CBCs, in total, statewide.
In 2017-18 numbers were up a bit with a total of 41 on Oregon CBCs, but only
2 in the Willamette Valley, and only 5 on coastal CBCs.
I did look at eBird and it gives no real clues. If you add up all of the
reports from the western U.S. and Canada in this winter and last, I doubt it
would add up to a tenth of what you could find on the Oregon State campus on
an average day in April. Here and there you might find a report of 15 or 25
birds, but most reports are of singles or a handful of birds. Certainly
nothing like the flocks of 100+ that I remember encountering at the Summer
Lake Rest Area in winter 10-15 years ago.
Any ideas?
--
Joel Geier
Camp Adair area north of Corvallis
<EveningGrosbeaksPacific.png>
