Relative Vulnerability of PIT‐Tagged Subyearling Fall Chinook Salmon to Predation by Caspian Terns and Double‐Crested Cormorants in the Columbia River Estuary

We quantified the percentage of PIT‐tagged subyearling fall Chinook Salmon Oncorhynchus tshawytscha that were consumed by Caspian terns Hydroprogne caspia and double‐crested cormorants Phalacrocorax auritus nesting on East Sand Island in the Columbia River estuary by electronically recovering PIT tags that were deposited on the bird colonies. We released 23 groups of PIT‐tagged subyearling fall Chinook Salmon from hatcheries in the lower...