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• 1. [Article] Colony Connectivity of Pacific Coast Double-Crested Cormorants Based on Post-Breeding Dispersal From the Region’s Largest Colony

  This is the publisher’s final pdf. The published article is copyrighted by John Wiley & Sons, Inc. and can be found at: http://onlinelibrary.wiley.com/journal/10.1002/%28ISSN%291937-2817. To the best of ...

  Citation × Citation Citation Abstract Copy Title: Colony Connectivity of Pacific Coast Double-Crested Cormorants Based on Post-Breeding Dispersal From the Region’s Largest Colony Author: Roby, Daniel D., Lyons, Donald E., Adkins, Jessica Y., Courtot, Karen N., Larsen, R. Scott, King, D. Tommy This is the publisher’s final pdf. The published article is copyrighted by John Wiley & Sons, Inc. and can be found at: http://onlinelibrary.wiley.com/journal/10.1002/%28ISSN%291937-2817. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. Title: Colony Connectivity of Pacific Coast Double-Crested Cormorants Based on Post-Breeding Dispersal From the Region’s Largest Colony Author: Roby, Daniel D., Lyons, Donald E., Adkins, Jessica Y., Courtot, Karen N., Larsen, R. Scott, King, D. Tommy This is the publisher’s final pdf. The published article is copyrighted by John Wiley & Sons, Inc. and can be found at: http://onlinelibrary.wiley.com/journal/10.1002/%28ISSN%291937-2817. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. Close

• 2. [Article] Quantifying Avian Predation on Fish Populations: Integrating Predator-Specific Deposition Probabilities in Tag Recovery Studies

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Taylor ...

  Citation × Citation Citation Abstract Copy Title: Quantifying Avian Predation on Fish Populations: Integrating Predator-Specific Deposition Probabilities in Tag Recovery Studies Author: Evans, Allen F., Roby, Daniel D., Cramer, Bradley M., Lyons, Donald E., Hostetter, Nathan J., Collis, Ken To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Taylor & Francis and can be found at: http://www.tandfonline.com/loi/utaf20#.VVYI7UZSVAM. Title: Quantifying Avian Predation on Fish Populations: Integrating Predator-Specific Deposition Probabilities in Tag Recovery Studies Author: Evans, Allen F., Roby, Daniel D., Cramer, Bradley M., Lyons, Donald E., Hostetter, Nathan J., Collis, Ken To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Taylor & Francis and can be found at: http://www.tandfonline.com/loi/utaf20#.VVYI7UZSVAM. Close

• 3. [Article] Systemwide Evaluation of Avian Predation on Juvenile Salmonids from the Columbia River Based on Recoveries of Passive Integrated Transponder Tags

  This is the publisher’s final pdf. The article is copyrighted by the American Fisheries Society and published by Taylor & Francis. It can be found at: http://www.tandfonline.com/toc/utaf20/current. To ...

  Citation × Citation Citation Abstract Copy Title: Systemwide Evaluation of Avian Predation on Juvenile Salmonids from the Columbia River Based on Recoveries of Passive Integrated Transponder Tags Author: Evans, Allen F., Ledgerwood, Richard D., Sandford, Benjamin P., Roby, Daniel D., Lyons, Donald E., Collis, Ken, Sebring, Scott, Hostetter, Nathan J. This is the publisher’s final pdf. The article is copyrighted by the American Fisheries Society and published by Taylor & Francis. It can be found at: http://www.tandfonline.com/toc/utaf20/current. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. Title: Systemwide Evaluation of Avian Predation on Juvenile Salmonids from the Columbia River Based on Recoveries of Passive Integrated Transponder Tags Author: Evans, Allen F., Ledgerwood, Richard D., Sandford, Benjamin P., Roby, Daniel D., Lyons, Donald E., Collis, Ken, Sebring, Scott, Hostetter, Nathan J. This is the publisher’s final pdf. The article is copyrighted by the American Fisheries Society and published by Taylor & Francis. It can be found at: http://www.tandfonline.com/toc/utaf20/current. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. Close

• 4. [Article] Potential Effects of Management on Caspian Tern Hydroprogne caspia Predation on Juvenile Salmonids at a Colony in San Francisco Bay, California

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is published by Taylor & ...

  Citation × Citation Citation Abstract Copy Title: Potential Effects of Management on Caspian Tern Hydroprogne caspia Predation on Juvenile Salmonids at a Colony in San Francisco Bay, California Author: Evans, Allen F., Adrean, Lindsay J., Roby, Daniel D., Lyons, Donald E., Collis, Ken To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is published by Taylor & Francis and can be found at: http://www.taylorandfrancis.com. Copyrighted by American Fisheries Society (http://afsjournals.org/). Title: Potential Effects of Management on Caspian Tern Hydroprogne caspia Predation on Juvenile Salmonids at a Colony in San Francisco Bay, California Author: Evans, Allen F., Adrean, Lindsay J., Roby, Daniel D., Lyons, Donald E., Collis, Ken To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is published by Taylor & Francis and can be found at: http://www.taylorandfrancis.com. Copyrighted by American Fisheries Society (http://afsjournals.org/). Close

• 5. [Article] Recent Population Size, Trends, and Limiting Factors for the Double-Crested Cormorant in Western North America

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article was published by John Wiley & Sons ...

  Citation × Citation Citation Abstract Copy Title: Recent Population Size, Trends, and Limiting Factors for the Double-Crested Cormorant in Western North America Author: Carter, Harry R., Roby, Daniel D., Shuford, W. David, Lyons, Donald E., Adkins, Jessica Y., Capitolo, Phillip J., Collis, Ken, Courtot, Karen N. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article was published by John Wiley & Sons Ltd. and is in the public domain. The published article can be found at: http://onlinelibrary.wiley.com/journal/10.1002/%28ISSN%291937-2817. Title: Recent Population Size, Trends, and Limiting Factors for the Double-Crested Cormorant in Western North America Author: Carter, Harry R., Roby, Daniel D., Shuford, W. David, Lyons, Donald E., Adkins, Jessica Y., Capitolo, Phillip J., Collis, Ken, Courtot, Karen N. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The article was published by John Wiley & Sons Ltd. and is in the public domain. The published article can be found at: http://onlinelibrary.wiley.com/journal/10.1002/%28ISSN%291937-2817. Close

• 6. [Article] Bioenergetics-based predator-prey relationships between piscivorous birds and juvenile salmonids in the Columbia River estuary

  This dissertation focuses on the predator-prey relationship between two species of avian predators, Caspian terns (Hydroprogne caspia) and double-crested cormorants (Phalacrocorax auritus), and one of ...

  Citation × Citation Citation Abstract Copy Title: Bioenergetics-based predator-prey relationships between piscivorous birds and juvenile salmonids in the Columbia River estuary Author: Lyons, Donald E. This dissertation focuses on the predator-prey relationship between two species of avian predators, Caspian terns (Hydroprogne caspia) and double-crested cormorants (Phalacrocorax auritus), and one of their important prey types, juvenile salmonids (Oncorhynchus spp.), in the Columbia River estuary of Oregon and Washington states during the period 1998 – 2007. I used a data-rich bioenergetics framework to estimate juvenile salmonid consumption by these two avian predators, assessed impacts to at-risk salmonid populations by estimating salmonid mortality rates due to avian predation, and estimated potential demographic benefits to salmonids if avian predation were reduced. The managed relocation of the Caspian tern colony from Rice Island to East Sand Island, lower in the Columbia River estuary, reduced tern predation on salmonids from over 11 million smolts consumed annually to 4 – 7 million, but those benefits accrued primarily to sub-yearling Chinook salmon (O. tshawytscha). Combined consumption of juvenile salmonids by Caspian terns and double-crested cormorants in the Columbia River estuary was ca. 7 – 15 million smolts per year during 2006-2007, causing an 8 – 17% mortality rate among smolts migrating through the estuary, with higher mortality rates for steelhead (O. mykiss) and coho salmon (O. kisutch). Under a potential management scenario to reduce avian predation by both species, improvements in the average annual population growth rate (λ) of salmonids ranged from 0.4% for sub-yearling Chinook to 3.1% for coho. These improvements are generally less than what is possible from altered hydropower system operation within the Columbia Basin for salmonid populations that are more severely affected by dams. For a few salmonid populations, reduced avian predation might contribute to stabilizing the population (λ = 1), but would need to be part of a broader recovery strategy to ensure population growth and recovery (λ > 1). Climate was an important factor modulating Caspian tern predation on salmonids, with greater consumption of smolts occurring in years of cooler ocean conditions and higher Columbia River flows. Climate did not contribute to variation in consumption of salmonids by cormorants, perhaps due to the larger effect of growth in the size of the cormorant colony during the study period. Due to current trends in colony size (terns: stable, cormorants: increasing) and the planned dispersal of a portion of the tern population, cormorant predation will likely be a more significant mortality factor for Columbia Basin salmonids in the future than will tern predation. A critical unknown factor remains; that is the degree to which reductions in avian predation on salmonids might be compensated for by other salmonid mortality factors. Title: Bioenergetics-based predator-prey relationships between piscivorous birds and juvenile salmonids in the Columbia River estuary Author: Lyons, Donald E. This dissertation focuses on the predator-prey relationship between two species of avian predators, Caspian terns (Hydroprogne caspia) and double-crested cormorants (Phalacrocorax auritus), and one of their important prey types, juvenile salmonids (Oncorhynchus spp.), in the Columbia River estuary of Oregon and Washington states during the period 1998 – 2007. I used a data-rich bioenergetics framework to estimate juvenile salmonid consumption by these two avian predators, assessed impacts to at-risk salmonid populations by estimating salmonid mortality rates due to avian predation, and estimated potential demographic benefits to salmonids if avian predation were reduced. The managed relocation of the Caspian tern colony from Rice Island to East Sand Island, lower in the Columbia River estuary, reduced tern predation on salmonids from over 11 million smolts consumed annually to 4 – 7 million, but those benefits accrued primarily to sub-yearling Chinook salmon (O. tshawytscha). Combined consumption of juvenile salmonids by Caspian terns and double-crested cormorants in the Columbia River estuary was ca. 7 – 15 million smolts per year during 2006-2007, causing an 8 – 17% mortality rate among smolts migrating through the estuary, with higher mortality rates for steelhead (O. mykiss) and coho salmon (O. kisutch). Under a potential management scenario to reduce avian predation by both species, improvements in the average annual population growth rate (λ) of salmonids ranged from 0.4% for sub-yearling Chinook to 3.1% for coho. These improvements are generally less than what is possible from altered hydropower system operation within the Columbia Basin for salmonid populations that are more severely affected by dams. For a few salmonid populations, reduced avian predation might contribute to stabilizing the population (λ = 1), but would need to be part of a broader recovery strategy to ensure population growth and recovery (λ > 1). Climate was an important factor modulating Caspian tern predation on salmonids, with greater consumption of smolts occurring in years of cooler ocean conditions and higher Columbia River flows. Climate did not contribute to variation in consumption of salmonids by cormorants, perhaps due to the larger effect of growth in the size of the cormorant colony during the study period. Due to current trends in colony size (terns: stable, cormorants: increasing) and the planned dispersal of a portion of the tern population, cormorant predation will likely be a more significant mortality factor for Columbia Basin salmonids in the future than will tern predation. A critical unknown factor remains; that is the degree to which reductions in avian predation on salmonids might be compensated for by other salmonid mortality factors. Close