Index Catalog // ScholarsArchive@OSU

Creator:: Evans, Allen F., Payton, Quinn, Turecek, Aaron, Cramer, Bradley, Collis, Ken, Roby, Daniel D., Loschl, Peter J., Sullivan, Leah, Skalski, John, Weiland, Mark, and Dotson, Curtis
Abstract:: We evaluated the impact of predation on juvenile steelhead Oncorhynchus mykiss and yearling and subyearling Chinook Salmon O. tshawytscha by piscivorous waterbirds from 11 different breeding colonies in the Columbia River basin during 2012 and 2014. Fish were tagged with both acoustic tags and PIT tags and were tracked via...
Resource Type:: Article

Creator:: Hostetter, Nathan J., Evans, Allen F., Roby, Daniel D., and Collis, Ken
Abstract:: Identification of the factors that influence susceptibility to predation can aid in developing management strategies to recover fish populations of conservation concern. Predator-prey relationships can be influenced by numerous factors, including prey condition, prey size, and environmental conditions. We investigated these factors by using juvenile steelhead Oncorhynchus mykiss from the...
Resource Type:: Article

Creator:: Adrean, Lindsay J., Roby, Daniel D., Lyons, Donald E., Collis, Ken, and Evans, Allen F.
Abstract:: San Francisco Bay is a proposed relocation site for some of the Caspian terns Hydroprogne caspia currently nesting at the world's largest colony for the species in the Columbia River estuary and consuming salmonids listed under the U. S. Endangered Species Act (ESA). However, several runs of salmonids listed under...
Resource Type:: Article

Creator:: Paredes, Rosana, Harding, Ann M. A., Irons, David B., Roby, Daniel D., Suryan, Robert M., Orben, Rachael A., Renner, Heather, Young, Rebecca, and Kitaysky, Alexander
Abstract:: As central-place foragers, seabirds from colonies located close to multiple and/or productive marine habitats might experience increased foraging opportunities and enhanced resilience to food shortages. We tested whether this hypothesis might explain divergent trends in 3 populations of black-legged kittiwakes Rissa tridactyla, a surface-feeding piscivore, in the eastern Bering Sea....
Resource Type:: Article

Creator:: Collis, Ken, Roby, Daniel D., Larson, Keith W., Adrean, Lindsay J., Nelson, S. Kim, Evans, Allen F., Hostetter, Nathan, Battaglia, Dan, Lyons, Donald E., Marcella, Tim, and Patterson, Allison
Abstract:: Colony size, nesting ecology and diet of Caspian Terns (Hydroprogne caspia) were investigated in the San Francisco Bay area (SFBA) during 2003-2009 to assess the potential for conservation of the tern breeding population and possible negative effects of predation on survival of juvenile salmonids (Oncorhynchus spp.). Numbers of breeding Caspian...
Resource Type:: Article

Creator:: Courtot, Karen N., Roby, Daniel D., Adkins, Jessica Y., Lyons, Donald E., King, D. Tommy, and Larsen, R. Scott
Abstract:: To reduce conflicts with fish resources, other colonial waterbirds, and damage to habitats, double-crested cormorants (Phalacrocorax auritus) are currently controlled (lethally and non-lethally) throughout much of their range. Concerns are growing over the Pacific Coast's largest double-crested cormorant colony at East Sand Island (ESI), Oregon near the mouth of the...
Resource Type:: Article

Creator:: Evans, Allen F., Hostetter, Nathan J., Roby, Daniel D., Collis, Ken, Lyons, Donald E., Sandford, Benjamin P., Ledgerwood, Richard D., and Sebring, Scott
Abstract:: We recovered passive integrated transponder (PIT) tags from nine piscivorous waterbird colonies in the Columbia River basin to evaluate avian predation on Endangered Species Act (ESA)-listed salmonid Oncorhynchus spp. populations during 2007–2010. Avian predation rates were calculated based on the percentage of PIT-tagged juvenile salmonids that were detected as passing...
Resource Type:: Article

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