Subject: Bird counts
Date: Jan 13 11:04:19 1995
From: "Michelsen, Teresa" - TEMI461 at ecy.wa.gov



Does anyone have the bird counts for Seattle CBC? I'd be interested...

I am attending the Puget Sound Research '95 conference in Bellevue this
week, and thought Tweeters might be interested in this abstract regarding
winter bird counts as one example of how CBC data can be used:

Winter Shorebird Abundance at Greater Puget Sound Estuaries: Recent Census
Results and Identification of Potential Monitoring Sites. Joseph B.
Buchanan, WA Dept. of Wildlife and Joseph R. Evenson, Cascadia Research
Collective.

Recent monitoring information from eastern North America indicates that
several Nearctic shorebird species have suffered population declines.
Before monitoring of shorebird populations in western North America can
occur, it is necessary to identify potential monitoring sites. Working with
Point Reyes Bird Observatory, we coordinated with Christmas bird count
participants and other volunteers to conduct single mid-winter shorebird
couts in 1990-91, 1992-93, and 1993-94. Ground-based and aerial counts were
conducted at 58 sites in the Greater Puget Sound (GPS) region. Census sites
were distributed among four sub-regions: North Puget Sound (15 sites),
Strait of Juan de Fuca and Admiralty Inlet (12 sites), Central and Southern
Puget Sound (18 sites) and Hood Canal (13 sites).

We identified 21 sites that supported >1000 shorebirds in at least one of
the three winters. Of the 10 sites supporting >1000 birds in at least two
years, 8 were in Northern Puget Sound; the other two sites were Dungeness
Bay and Totten Inlet. There were no sites in Hood Canal that supported
>1000 shorebirds. The single highest counts were of 31,050 shorebirds at
the Port Susan complex (93-94) and 19,349 at Skagit Bay (92-93). The most
common species in the GPS was the Dunlin (Caladris alpina), typically
comprising about 95 percent of all shorebirds counted. Counts of only one
other species (Western Sandpiper, C. mauri) exceeded 1000 for the entire
GPS.

The substantial variation in count totals within and among years,
particularly in Northern Puget Sound, indicates that movements regularly
occur. Such movements necessitate additional counts to identify sites that
typically support large numbers. Considering sites with 1,000 shorebirds in
all three years, or sites with 2000 shorebirds in at least one year, the
current data suggest that the most important wintering areas in the GPS are
Drayton Harbor, Birch Bay, Lummi Bay, Bellingham Bay, Samish Bay, Padilla
Bay, Fidalgo Bay, Skagit Bay, Port Susan, Crockett Lake, Snohomish River
Delta, Nisqually River, Totten Inlet, and Dungeness Bay.