Caspian Tern Decoys
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Caspian Tern – Hollow, rotomolded polyethylene, 1”
hole for wooden dowel anchor or plastic plug.
In 1997, the U.S. Geological Survey-Oregon Cooperative Fish
and Wildlife Unit, Oregon State University and the Columbia
River Inter-Tribal Fish Commission began a study to assess
the impacts of fish eating water birds (including Caspian
Terns) on the survival of juvenile salmon in the Lower Columbia
River. Approximately 15,000 adult Caspians were nesting on
Rice Island, a dredged spoil island close to a salmon hatchery.
This colony was the largest known Caspian tern breeding colony
in the world, and supported about two-thirds of all the Caspian
terns nesting along the Pacific Coast of North America. It
was estimated that in 1998, the colony consumed 9-17% of the
smolts that reached the estuary. This level of smolt predation
prompted regional fish and wildlife managers to investigate
the feasibility of relocating the tern colony to East Sand
Island, 26 km from the hatchery. Using habitat modification
and social attraction, this ongoing program has successfully
relocated the colony to East Sand Island and significantly
reduced the proportion of juvenile salmonids in their diet.
Although considered a serious predator to the beleaguered
salmon stocks of the Columbia River, Caspian Terns also suffer
from environmental pressures and lack of suitable colony nesting
sites. In 2001 these agencies tested the feasibility of attracting
Caspian Terns to nest on a sand covered barge located in Commencement
Bay equipped with our decoys and q sound system. Terns responded
rapidly to the presence of the barge with approximately 388
nests in the first month.
(Source: www.columbiabirdresearch.org)
Other Caspian restoration projects have been or are being
conducted in California, Oregon and North Carolina.
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