Annika Walters, PhD (Former Employee)
Science and Products
Filter Total Items: 71
Informed breeding dispersal following stochastic changes to patch quality in a pond-breeding amphibian Informed breeding dispersal following stochastic changes to patch quality in a pond-breeding amphibian
The unidirectional movement of animals between breeding patches (i.e. breeding dispersal) has profound implications for the ecological and evolutionary dynamics of spatially structured populations. In spatiotemporally variable environments, individuals are expected to adjust their dispersal decisions according to information gathered on the environmental and/or social cues that reflect...
Authors
Gabriel M. Barrile, Annika W. Walters, Matthew Webster, Anna D. Chalfoun
Historical data provide important context for understanding declines in Cutthroat Trout Historical data provide important context for understanding declines in Cutthroat Trout
We used historical stocking and population survey records of Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri and other salmonids in the North Fork Shoshone River drainage, Wyoming to summarize fish stocking history and population trends. Based on 98 years of historical records, we found that despite extensive stocking of Yellowstone Cutthroat Trout and minimal stocking of...
Authors
Brittany J. Nordberg, Elizabeth G. Mandeville, Annika W. Walters, Jason C. Burckhardt, Catherine E. Wagner
Biotic and abiotic determinants of finescale dace distribution at the southern edge of their range Biotic and abiotic determinants of finescale dace distribution at the southern edge of their range
Aim The factors that set range limits for animal populations can inform management plans aimed at maintaining regional biodiversity. We examine abiotic and biotic drivers of the distribution of finescale dace (Chrosomus neogaeus) in two Great Plains basins to identify limiting factors for a threatened freshwater fish population at the edge of their range.Location Great Plains, Nebraska...
Authors
Evan C. J. Booher, Annika W. Walters
Warmer temperatures interact with salinity to weaken physiological facilitation to stress in freshwater fishes Warmer temperatures interact with salinity to weaken physiological facilitation to stress in freshwater fishes
Management of stressors requires an understanding of how multiple stressors interact, how different species respond to those interactions and the underlying mechanisms driving observed patterns in species' responses. Salinization and rising temperatures are two pertinent stressors predicted to intensify in freshwater ecosystems, posing concern for how susceptible organisms achieve and...
Authors
Richard H. Walker, Geoffrey D. Smith, Spencer B Hudson, Susannah S. Susannah S. French, Annika W. Walters
Infection status as the basis for habitat choices in a wild amphibian Infection status as the basis for habitat choices in a wild amphibian
Animals challenged with disease may select specific habitat conditions that help prevent or reduce infection. Whereas preinfection avoidance of habitats with a high risk of disease exposure has been documented in both captive and free-ranging animals, evidence of switching habitats after infection to support the clearing of the infection is limited to laboratory experiments. The extent...
Authors
Gabriel M. Barrile, Anna D. Chalfoun, Annika W. Walters
Evaluation of Potential Translocation Sites for an Imperiled Cyprinid, theHornyhead Chub Evaluation of Potential Translocation Sites for an Imperiled Cyprinid, theHornyhead Chub
Translocation of isolated species into suitable habitats may help secure vulnerable, geographically limited species. Due to the decline of Wyoming Hornyhead Chub Nocomis biguttatus, conservation actions such as translocation of populations within the plausible historical range are being considered to improve population redundancy and resiliency to disturbance events. Translocation of...
Authors
Brian T. Hickerson, Annika W. Walters
Anthropogenic land‐use change intensifies the effect of low flows on stream fishes Anthropogenic land‐use change intensifies the effect of low flows on stream fishes
As ecosystems experience simultaneous disturbances, it is critical to understand how multiple stressors interact to affect ecological change. Land‐use change and extreme flow events are two important stressors that could interact to affect fish populations.We evaluated the individual and interactive effects of discharge and land‐use change associated with oil and natural gas development...
Authors
Richard H. Walker, Carlin Girard, Samantha L. Alford, Annika W. Walters
A mechanistic understanding of ecological responses to land-use change in headwater streams A mechanistic understanding of ecological responses to land-use change in headwater streams
Anthropogenic activities, such as oil and natural gas development (ONGD), have significantly altered the landscape. It is often challenging to identify the mechanistic processes underlying ecological responses to land-use change (LUC). In aquatic ecosystems, alterations to habitat and food availability and water quality associated with increased LUC are key mechanistic pathways that...
Authors
Richard H. Walker, Annika W. Walters
Effects of multiple nonnative fish on an imperiled cyprinid, Hornyhead Chub Effects of multiple nonnative fish on an imperiled cyprinid, Hornyhead Chub
Nonnative fish can have substantial negative effects on the abundance and distribution of native fishes through predation and competition. Nonnative predators are of particular interest because they represent novel threats to native prey species that are not adapted to their presence. Prey species with limited distributions or population sizes may be particularly vulnerable to the...
Authors
Brian T. Hickerson, Bryan M. Maitland, Annika W. Walters
Variable hybridization outcomes in trout are predicted by historical fish stocking and environmental context Variable hybridization outcomes in trout are predicted by historical fish stocking and environmental context
Hybridization can profoundly affect the genomic composition and phenotypes of closely related species, and provides an opportunity to identify mechanisms that maintain reproductive isolation between species. Recent evidence suggests that hybridization outcomes within a species pair can vary across locations. However, we still don’t know how extensive variation in outcomes of...
Authors
Elizabeth G. Mandeville, Annika W. Walters, Brittany J. Nordberg, Karly H. Higgins, Jason C. Burckhardt, Catherine E. Wagner
Integrating fish assemblage data, modeled stream temperatures, and thermal tolerance metrics to develop thermal guilds for water temperature regulation: Wyoming case study Integrating fish assemblage data, modeled stream temperatures, and thermal tolerance metrics to develop thermal guilds for water temperature regulation: Wyoming case study
Many streams are experiencing increased average temperatures due to anthropogenic activity and climate change. As a result, surface water temperature regulation is critical for preserving a diverse stream fish species assemblage. The development of temperature regulations has generally been based on laboratory measurements of individual species' thermal tolerances rather than community...
Authors
Caitlin P. Mandeville, Frank J. Rahel, Lindsay S. Patterson, Annika W. Walters
U.S. Geological Survey science for the Wyoming Landscape Conservation Initiative—2017 annual report U.S. Geological Survey science for the Wyoming Landscape Conservation Initiative—2017 annual report
The Wyoming Landscape Conservation Initiative (WLCI) was established in 2008 to address the scientific and conservation questions associated with land use changes because of energy development and other factors in southwest Wyoming. Over the past decade, partners from U.S. Geological Survey (USGS), State and Federal land management agencies, universities, and the public have collaborated...
Authors
Linda Zeigenfuss, Ellen Aikens, Cameron L. Aldridge, Patrick J. Anderson, Timothy J. Assal, Zachary H. Bowen, Anna D. Chalfoun, Geneva W. Chong, Cheryl A. Eddy-Miller, Stephen S. Germaine, Tabitha A. Graves, Collin G. Homer, Christopher Huber, Aaron N. Johnston, Matthew J. Kauffman, Daniel J. Manier, Ryan R. McShane, Kirk A. Miller, Adrian P. Monroe, Anna Ortega, Annika W. Walters, Teal B. Wyckoff
Science and Products
Filter Total Items: 71
Informed breeding dispersal following stochastic changes to patch quality in a pond-breeding amphibian Informed breeding dispersal following stochastic changes to patch quality in a pond-breeding amphibian
The unidirectional movement of animals between breeding patches (i.e. breeding dispersal) has profound implications for the ecological and evolutionary dynamics of spatially structured populations. In spatiotemporally variable environments, individuals are expected to adjust their dispersal decisions according to information gathered on the environmental and/or social cues that reflect...
Authors
Gabriel M. Barrile, Annika W. Walters, Matthew Webster, Anna D. Chalfoun
Historical data provide important context for understanding declines in Cutthroat Trout Historical data provide important context for understanding declines in Cutthroat Trout
We used historical stocking and population survey records of Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri and other salmonids in the North Fork Shoshone River drainage, Wyoming to summarize fish stocking history and population trends. Based on 98 years of historical records, we found that despite extensive stocking of Yellowstone Cutthroat Trout and minimal stocking of...
Authors
Brittany J. Nordberg, Elizabeth G. Mandeville, Annika W. Walters, Jason C. Burckhardt, Catherine E. Wagner
Biotic and abiotic determinants of finescale dace distribution at the southern edge of their range Biotic and abiotic determinants of finescale dace distribution at the southern edge of their range
Aim The factors that set range limits for animal populations can inform management plans aimed at maintaining regional biodiversity. We examine abiotic and biotic drivers of the distribution of finescale dace (Chrosomus neogaeus) in two Great Plains basins to identify limiting factors for a threatened freshwater fish population at the edge of their range.Location Great Plains, Nebraska...
Authors
Evan C. J. Booher, Annika W. Walters
Warmer temperatures interact with salinity to weaken physiological facilitation to stress in freshwater fishes Warmer temperatures interact with salinity to weaken physiological facilitation to stress in freshwater fishes
Management of stressors requires an understanding of how multiple stressors interact, how different species respond to those interactions and the underlying mechanisms driving observed patterns in species' responses. Salinization and rising temperatures are two pertinent stressors predicted to intensify in freshwater ecosystems, posing concern for how susceptible organisms achieve and...
Authors
Richard H. Walker, Geoffrey D. Smith, Spencer B Hudson, Susannah S. Susannah S. French, Annika W. Walters
Infection status as the basis for habitat choices in a wild amphibian Infection status as the basis for habitat choices in a wild amphibian
Animals challenged with disease may select specific habitat conditions that help prevent or reduce infection. Whereas preinfection avoidance of habitats with a high risk of disease exposure has been documented in both captive and free-ranging animals, evidence of switching habitats after infection to support the clearing of the infection is limited to laboratory experiments. The extent...
Authors
Gabriel M. Barrile, Anna D. Chalfoun, Annika W. Walters
Evaluation of Potential Translocation Sites for an Imperiled Cyprinid, theHornyhead Chub Evaluation of Potential Translocation Sites for an Imperiled Cyprinid, theHornyhead Chub
Translocation of isolated species into suitable habitats may help secure vulnerable, geographically limited species. Due to the decline of Wyoming Hornyhead Chub Nocomis biguttatus, conservation actions such as translocation of populations within the plausible historical range are being considered to improve population redundancy and resiliency to disturbance events. Translocation of...
Authors
Brian T. Hickerson, Annika W. Walters
Anthropogenic land‐use change intensifies the effect of low flows on stream fishes Anthropogenic land‐use change intensifies the effect of low flows on stream fishes
As ecosystems experience simultaneous disturbances, it is critical to understand how multiple stressors interact to affect ecological change. Land‐use change and extreme flow events are two important stressors that could interact to affect fish populations.We evaluated the individual and interactive effects of discharge and land‐use change associated with oil and natural gas development...
Authors
Richard H. Walker, Carlin Girard, Samantha L. Alford, Annika W. Walters
A mechanistic understanding of ecological responses to land-use change in headwater streams A mechanistic understanding of ecological responses to land-use change in headwater streams
Anthropogenic activities, such as oil and natural gas development (ONGD), have significantly altered the landscape. It is often challenging to identify the mechanistic processes underlying ecological responses to land-use change (LUC). In aquatic ecosystems, alterations to habitat and food availability and water quality associated with increased LUC are key mechanistic pathways that...
Authors
Richard H. Walker, Annika W. Walters
Effects of multiple nonnative fish on an imperiled cyprinid, Hornyhead Chub Effects of multiple nonnative fish on an imperiled cyprinid, Hornyhead Chub
Nonnative fish can have substantial negative effects on the abundance and distribution of native fishes through predation and competition. Nonnative predators are of particular interest because they represent novel threats to native prey species that are not adapted to their presence. Prey species with limited distributions or population sizes may be particularly vulnerable to the...
Authors
Brian T. Hickerson, Bryan M. Maitland, Annika W. Walters
Variable hybridization outcomes in trout are predicted by historical fish stocking and environmental context Variable hybridization outcomes in trout are predicted by historical fish stocking and environmental context
Hybridization can profoundly affect the genomic composition and phenotypes of closely related species, and provides an opportunity to identify mechanisms that maintain reproductive isolation between species. Recent evidence suggests that hybridization outcomes within a species pair can vary across locations. However, we still don’t know how extensive variation in outcomes of...
Authors
Elizabeth G. Mandeville, Annika W. Walters, Brittany J. Nordberg, Karly H. Higgins, Jason C. Burckhardt, Catherine E. Wagner
Integrating fish assemblage data, modeled stream temperatures, and thermal tolerance metrics to develop thermal guilds for water temperature regulation: Wyoming case study Integrating fish assemblage data, modeled stream temperatures, and thermal tolerance metrics to develop thermal guilds for water temperature regulation: Wyoming case study
Many streams are experiencing increased average temperatures due to anthropogenic activity and climate change. As a result, surface water temperature regulation is critical for preserving a diverse stream fish species assemblage. The development of temperature regulations has generally been based on laboratory measurements of individual species' thermal tolerances rather than community...
Authors
Caitlin P. Mandeville, Frank J. Rahel, Lindsay S. Patterson, Annika W. Walters
U.S. Geological Survey science for the Wyoming Landscape Conservation Initiative—2017 annual report U.S. Geological Survey science for the Wyoming Landscape Conservation Initiative—2017 annual report
The Wyoming Landscape Conservation Initiative (WLCI) was established in 2008 to address the scientific and conservation questions associated with land use changes because of energy development and other factors in southwest Wyoming. Over the past decade, partners from U.S. Geological Survey (USGS), State and Federal land management agencies, universities, and the public have collaborated...
Authors
Linda Zeigenfuss, Ellen Aikens, Cameron L. Aldridge, Patrick J. Anderson, Timothy J. Assal, Zachary H. Bowen, Anna D. Chalfoun, Geneva W. Chong, Cheryl A. Eddy-Miller, Stephen S. Germaine, Tabitha A. Graves, Collin G. Homer, Christopher Huber, Aaron N. Johnston, Matthew J. Kauffman, Daniel J. Manier, Ryan R. McShane, Kirk A. Miller, Adrian P. Monroe, Anna Ortega, Annika W. Walters, Teal B. Wyckoff