WEST COAST SANDHILL CRANE STUDY
A satellite telemetry project sponsored by the West Coast Crane Working Group, in partnership with
Ridgefield National Wildlife Refuge (U.S. Fish and Wildlife Service) and Sauvie Island Wildlife Area
(Oregon Department of Fish and Wildlife), with funding contributed by the Paul L. King Charitable Foundation,
The Foley/Frischkorn Wildlife and Conservation Fund, Chevron Research and
Technology Company, and other appreciated supporters.
Gary L. Ivey, Thomas J. Hoffmann, and Caroline P. Herziger.
In November 2001, the West Coast Crane Working Group initiated a pilot project using satellite telemetry to track movements of
sandhill cranes from Ridgefield National Wildlife Refuge (NWR) in Washington and Sauvie Island Wildlife Area (WA), just across
the Columbia River in Oregon, to other staging and wintering areas, as well as nesting grounds. Read why the study was initiated,
learn how cranes were captured, and view maps of their movements.
There are three subspecies or races of sandhill cranes (Grus canadensis) that occur in Washington and Oregon. The greater (G. c.
tabida) breeds, while some Canadian (G. c. rowani) and lesser (G. c. canadensis) sandhill cranes stop in these states during
migration between their northern breeding grounds and wintering grounds in California, with some staying to winter along the
Columbia River near Vancouver and Portland. The greater sandhill crane is the largest, the lesser the smallest, and the Canadian
intermediate in size. In Washington state, the sandhill crane is considered an Endangered Species, while in Oregon, the greater
sandhill crane is classified as Sensitive.
Sandhill cranes use Ridgefield NWR, Sauvie Island WA, and surrounding farm
lands. This region serves both as a staging and wintering area, but the nesting
locations and migratory routes to nesting areas and other migrating and wintering
sites are unknown. It has been assumed that all three subspecies of cranes use this
area, however, there is a degree of uncertainty about the subspecies composition of
these flocks. Therefore, in order to determine subspecies, breeding areas, migratory
paths, and other wintering areas, we initiated this study using satellite transmitters
called Platform Transmitting Terminals (PTTs). Initially, the focus was to be on the
lesser subspecies, however, all the birds trapped and those carefully observed in the
area did not appear to be lessers, therefore, past theories about lesser sandhill cranes
are now in question. Perhaps lessers do use the area during early fall migration, but
none were identified during late fall or spring. No greater sandhill cranes were noted
Located just west of the city of Ridgefield in Clark County,
Washington, Ridgefield NWR lies between channels of the Columbia River and
contains about 5,000 acres. Across the Columbia in Oregon, Sauvie Island WA
contains about 12,000 acres, in Multnomah and Columbia Counties. These two areas provide corn and barley fields,
pastures, and wetlands which are used by sandhill cranes for feeding
and roosting. Cranes move back and forth between the two areas, and
also use private farm fields including Woodland Bottoms, Squaw
Island, and Vancouver Bottoms in Washington, and Sauvie Island and
east of Scappoose along the Multnomah Channel in Oregon.
Six of the 8 cranes captured were marked with PTTs; 2
others only received colored bands for visual
identification because we desired to increase our chances
of capturing California migrants, and they were captured
from the same flocks as PTT birds. Four of the cranes
were captured at Ridgefield NWR and 4 at Sauvie Island
Migration: We tracked the movements of the PTT birds
via satellite technology, and documented their spring migration routes and
destinations. Based on the data we obtained, it appears that the birds move down
the Columbia River, follow the Washington coast northward, cross Cape Flattery,
across Vancouver Island, and up the coast of British Columbia (BC).
Final Destinations: One crane migrated to Dall
Island in southwest Alaska while the other 5
cranes stopped along the northern and central B.C. coast. Of those 5, one was on the
mainland near Port Edward while the other 4
were on islands off the coast. One bird each was
on McCauley Island, Banks Island, Dowager
Island and Princess Royal Island. All six birds have been at these
locations since late April and are probably
Subspecies: The measurements of the cranes we captured were mostly within the range of the Canadian subspecies and the head
shape was that of Canadians. The migration pattern and destinations of these few birds also suggest that statements of the Canadian
subspecies using the coast of BC are correct (see
Who Are These Cranes?).
Click the following items to see detailed results for this study: