Decoys

Caspian Tern

Photo: Columbia River Avian Predation Program

Hollow, rotomolded polyethylene
1” hole with plastic plug (included) or wooden dowel (not included)

In 1997 the US Geological Survey-Oregon Cooperative Fish and Wildlife Unit, Oregon State University and the Columbia Inter-Tribal Commission began a large study to assess the impacts of fish eating (piscivorous) water birds, including Caspian Terns, on the survival of juvenile salmon in the Lower Columbia River.  At that time, approximately 15,000 adult Caspian Terns were nesting on Rice Island, a dredged spoil island close to a salmon hatchery.  This colony was the largest known Caspian breeding colony in the world and accounted for about two-thirds of all the Caspian Terns nesting along the Pacific Coast of North America.  In 1998 it was estimated that the colony consumed 9-17% of the smolts that reached the estuary.  The level of smolt predation prompted regional fish and wildlife managers to investigate the feasibility of relocating this colony to East Sand Island, 26km from the hatchery.  Using habitat modification and social attraction, this ongoing program successfully relocated the colony and significantly reduced the percentage of juvenile salmonids in the Caspian’s diet.

Although considered a serious predator of the beleaguered salmon stocks of the Columbia River Basin, Caspian Tern also suffer from environmental pressure and lack of suitable colony nesting sites.  In 2001 these agencies tested the feasibility of attracting Caspians to next on a sand covered barge equipped with our decoys and a sound system. They placed the barge in located in Commencement Bay in Puget Sound.  Terns responded rapidly to the presence of the barge with approximately 388 nests being built in the first month.  Since then, Caspian decoys have been used at numerous sites as part of this large, long-term project.

Additionally Caspian restoration projects have been done multiple sites in North Carolina, California and Canada, all with good results.

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