Craig Stricker, PhD
Craig Stricker is a Research Biologist at the Fort Collins Science Center.
Science and Products
Filter Total Items: 17
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Filter Total Items: 82
Isotopic characterization of flight feathers in two pelagic seabirds: Sampling strategies for ecological studies
We wish to use stable-isotope analysis of flight feathers to understand the feeding behavior of pelagic seabirds, such as the Hawaiian Petrel (Pterodroma sandwichensis) and Newell’s Shearwater (Puffinus auricularis newelli). Analysis of remiges is particularly informative because the sequence and timing of remex molt are often known. The initial step, reported here, is to obtain accurate isotope v
Authors
Anne E. Wiley, Peggy H. Ostrom, Craig A. Stricker, Helen F. James, Hasand Gandhi
Stable isotopes differentiate bottlenose dolphins off west-central Florida
Distinguishing discrete population units among continuously distributed coastal small cetaceans is challenging and crucial to conservation. We evaluated the utility of stable isotopes in assessing group membership in bottlenose dolphins (Tursiops truncatus) off west-central Florida by analyzing carbon, nitrogen, and sulfur isotope values (δ13C, δ15N, and δ34S) of tooth collagen from stranded dolph
Authors
Nélio B. Barros, P. H. Ostrom, Craig A. Stricker, R.S. Wells
Evolution of Ore Deposits and Technology Transfer Project: Isotope and Chemical Methods in Support of the U.S. Geological Survey Science Strategy, 2003-2008
Principal functions of the U.S. Geological Survey (USGS) Mineral Resources Program are providing assessments of the location, quantity, and quality of undiscovered mineral deposits, and predicting the environmental impacts of exploration and mine development. The mineral and environmental assessments of domestic deposits are used by planners and decisionmakers to improve the stewardship of public
Authors
Robert O. Rye, Craig A. Johnson, Gary P. Landis, Albert H. Hofstra, Poul Emsbo, Craig A. Stricker, Andrew G. Hunt, Brian G. Rusk
Methylmercury cycling, bioaccumulation, and export from agricultural and non-agricultural wetlands in the Yolo Bypass
This 18-month field study addresses the seasonal and spatial patterns and processes controlling methylmercury (MeHg) production, bioaccumulation, and export from natural and agricultural wetlands of the Yolo Bypass Wildlife Area (YBWA). The data were collected in conjuntion with a Proposition 40 grant from the State Water Resources Control Board in support of the development of Best Management Pra
Authors
Lisamarie Windham-Myers, Mark Marvin-DiPasquale, Jacob Fleck, Charles N. Alpers, Joshua T. Ackerman, Collin A. Eagles-Smith, Craig Stricker, Mark Stephenson, David Feliz, Gary Gill, Philip Bachand, Ann Brice, Robin Kulakow
Migratory structure and geographic origins of hoary bats (Lasiurus cinereus) inferred from stable isotope analysis
No abstract available.
Authors
Paul M. Cryan, Craig A. Stricker, Mike B. Wunder
Are inland wolf-ungulate systems influenced by marine subsidies of Pacific salmon?
Wolves (Canis lupus) in North America are considered obligate predators of ungulates with other food resources playing little role in wolf population dynamics or wolf–prey relations. However, spawning Pacific salmon (Oncorhyncus spp.) are common throughout wolf range in northwestern North America and may provide a marine subsidy affecting inland wolf–ungulate food webs far from the coast. We condu
Authors
Layne G. Adams, Sean D. Farley, Craig A. Stricker, Dominic J. Demma, Gretchen H. Roffler, Dennis C. Miller, Robert O. Rye
Does a lack of design and repeatability compromise scientific criticism? A Response to Smith et al. (2009)
In a recent paper published in The Auk, Smith et al. (2009) raised serious concerns over an apparent lack of reproducibility in their study of stable hydrogen isotope values (δDf ) in raptor feathers. The authors based their concerns on results obtained from different laboratories to which they submitted original and blind “repeats” over a multiyear period. A regression of the original sample δD v
Authors
Michael B. Wunder, Keith A. Hobson, Jeff Kelly, Peter P. Marra, Leonard I Wassenaar, Craig A. Stricker, Richard R. Doucett
Stable isotope and trace element studies of black bear hair, Big Bend ecosystem, Texas and Mexico
Hair from black bears (Ursus americanus), collected from four areas in the Big Bend ecosystem, has been analyzed for stable isotopes of carbon, nitrogen, and sulfur to determine major food sources and for trace metals to infer possible effects of environmental contaminants. Results indicate that black bears are largely vegetarian, feeding on desert plants, nuts, and berries. Mercury concentrations
Authors
W.C. Pat Shanks, Eric C. Hellgren, Craig A. Stricker, Pamela A. Gemery-Hill, David P. Onorato
Discrimination of carbon and nitrogen isotopes from milk to serum and vibrissae in Alaska Steller sea lions (Eumetopias jubatus)
Knowledge of diet-tissue stable isotope discrimination is required to properly interpret stable isotope values and to identify possible diet shifts, such as might be expected from nursing through weaning. This study compared ??13C and ??15N of paired serum and vibrissal roots with those of ingested milk (n = 52) from free-ranging Steller sea lion (Eumetopias jubatus (Schreber, 1776)) pups (1-11 mo
Authors
V.K. Stegall, Sean D. Farley, Lorrie D. Rea, K.W. Pitcher, R. O. Rye, C.L. Kester, C. A. Stricker, C.R. Bern
The importance of hyporheic sediment respiration in several mid-order Michigan rivers: Comparison between methods in estimates of lotic metabolism
Metabolism was measured in four Michigan streams, comparing estimates made using a flow-through chamber designed to include the hyporheic zone to a 20 cm depth and a traditional closed chamber that enclosed to a 5 cm depth. Mean levels of gross primary productivity and community respiration were consistently greater in the flow-through chamber than the closed chamber in all streams. Ratios of prod
Authors
D.G. Uzarski, C. A. Stricker, T.M. Burton, D. K. King, A.D. Steinman
Non-USGS Publications**
Burton, T.M., Uzarski, D.G., Gathman, J.P. et al. Wetlands (1999) 19: 869. doi:10.1007/BF03161789
Uzarski, D., Burton, T. & Stricker, C. Hydrobiologia (2001) 455: 137. doi:10.1023/A:1011929719866
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
Filter Total Items: 17
No Result Found
Filter Total Items: 82
Isotopic characterization of flight feathers in two pelagic seabirds: Sampling strategies for ecological studies
We wish to use stable-isotope analysis of flight feathers to understand the feeding behavior of pelagic seabirds, such as the Hawaiian Petrel (Pterodroma sandwichensis) and Newell’s Shearwater (Puffinus auricularis newelli). Analysis of remiges is particularly informative because the sequence and timing of remex molt are often known. The initial step, reported here, is to obtain accurate isotope v
Authors
Anne E. Wiley, Peggy H. Ostrom, Craig A. Stricker, Helen F. James, Hasand Gandhi
Stable isotopes differentiate bottlenose dolphins off west-central Florida
Distinguishing discrete population units among continuously distributed coastal small cetaceans is challenging and crucial to conservation. We evaluated the utility of stable isotopes in assessing group membership in bottlenose dolphins (Tursiops truncatus) off west-central Florida by analyzing carbon, nitrogen, and sulfur isotope values (δ13C, δ15N, and δ34S) of tooth collagen from stranded dolph
Authors
Nélio B. Barros, P. H. Ostrom, Craig A. Stricker, R.S. Wells
Evolution of Ore Deposits and Technology Transfer Project: Isotope and Chemical Methods in Support of the U.S. Geological Survey Science Strategy, 2003-2008
Principal functions of the U.S. Geological Survey (USGS) Mineral Resources Program are providing assessments of the location, quantity, and quality of undiscovered mineral deposits, and predicting the environmental impacts of exploration and mine development. The mineral and environmental assessments of domestic deposits are used by planners and decisionmakers to improve the stewardship of public
Authors
Robert O. Rye, Craig A. Johnson, Gary P. Landis, Albert H. Hofstra, Poul Emsbo, Craig A. Stricker, Andrew G. Hunt, Brian G. Rusk
Methylmercury cycling, bioaccumulation, and export from agricultural and non-agricultural wetlands in the Yolo Bypass
This 18-month field study addresses the seasonal and spatial patterns and processes controlling methylmercury (MeHg) production, bioaccumulation, and export from natural and agricultural wetlands of the Yolo Bypass Wildlife Area (YBWA). The data were collected in conjuntion with a Proposition 40 grant from the State Water Resources Control Board in support of the development of Best Management Pra
Authors
Lisamarie Windham-Myers, Mark Marvin-DiPasquale, Jacob Fleck, Charles N. Alpers, Joshua T. Ackerman, Collin A. Eagles-Smith, Craig Stricker, Mark Stephenson, David Feliz, Gary Gill, Philip Bachand, Ann Brice, Robin Kulakow
Migratory structure and geographic origins of hoary bats (Lasiurus cinereus) inferred from stable isotope analysis
No abstract available.
Authors
Paul M. Cryan, Craig A. Stricker, Mike B. Wunder
Are inland wolf-ungulate systems influenced by marine subsidies of Pacific salmon?
Wolves (Canis lupus) in North America are considered obligate predators of ungulates with other food resources playing little role in wolf population dynamics or wolf–prey relations. However, spawning Pacific salmon (Oncorhyncus spp.) are common throughout wolf range in northwestern North America and may provide a marine subsidy affecting inland wolf–ungulate food webs far from the coast. We condu
Authors
Layne G. Adams, Sean D. Farley, Craig A. Stricker, Dominic J. Demma, Gretchen H. Roffler, Dennis C. Miller, Robert O. Rye
Does a lack of design and repeatability compromise scientific criticism? A Response to Smith et al. (2009)
In a recent paper published in The Auk, Smith et al. (2009) raised serious concerns over an apparent lack of reproducibility in their study of stable hydrogen isotope values (δDf ) in raptor feathers. The authors based their concerns on results obtained from different laboratories to which they submitted original and blind “repeats” over a multiyear period. A regression of the original sample δD v
Authors
Michael B. Wunder, Keith A. Hobson, Jeff Kelly, Peter P. Marra, Leonard I Wassenaar, Craig A. Stricker, Richard R. Doucett
Stable isotope and trace element studies of black bear hair, Big Bend ecosystem, Texas and Mexico
Hair from black bears (Ursus americanus), collected from four areas in the Big Bend ecosystem, has been analyzed for stable isotopes of carbon, nitrogen, and sulfur to determine major food sources and for trace metals to infer possible effects of environmental contaminants. Results indicate that black bears are largely vegetarian, feeding on desert plants, nuts, and berries. Mercury concentrations
Authors
W.C. Pat Shanks, Eric C. Hellgren, Craig A. Stricker, Pamela A. Gemery-Hill, David P. Onorato
Discrimination of carbon and nitrogen isotopes from milk to serum and vibrissae in Alaska Steller sea lions (Eumetopias jubatus)
Knowledge of diet-tissue stable isotope discrimination is required to properly interpret stable isotope values and to identify possible diet shifts, such as might be expected from nursing through weaning. This study compared ??13C and ??15N of paired serum and vibrissal roots with those of ingested milk (n = 52) from free-ranging Steller sea lion (Eumetopias jubatus (Schreber, 1776)) pups (1-11 mo
Authors
V.K. Stegall, Sean D. Farley, Lorrie D. Rea, K.W. Pitcher, R. O. Rye, C.L. Kester, C. A. Stricker, C.R. Bern
The importance of hyporheic sediment respiration in several mid-order Michigan rivers: Comparison between methods in estimates of lotic metabolism
Metabolism was measured in four Michigan streams, comparing estimates made using a flow-through chamber designed to include the hyporheic zone to a 20 cm depth and a traditional closed chamber that enclosed to a 5 cm depth. Mean levels of gross primary productivity and community respiration were consistently greater in the flow-through chamber than the closed chamber in all streams. Ratios of prod
Authors
D.G. Uzarski, C. A. Stricker, T.M. Burton, D. K. King, A.D. Steinman
Non-USGS Publications**
Burton, T.M., Uzarski, D.G., Gathman, J.P. et al. Wetlands (1999) 19: 869. doi:10.1007/BF03161789
Uzarski, D., Burton, T. & Stricker, C. Hydrobiologia (2001) 455: 137. doi:10.1023/A:1011929719866
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.