Susan Walls, Ph.D.
Susan Walls is a research wildlife biologist who serves as the coordinator and lead scientist for the southeastern region of the Amphibian Research and Monitoring Initiative (ARMI).
ARMI is a national program for which funding was appropriated by Congress in 2000 in response to mounting evidence and concern for declines of amphibians in the U.S. and worldwide. Susan's research group establishes and implements long-term monitoring of amphibians at key sites within the southeastern U.S. (AL, GA, FL, SC, NC and TN) and conducts research on potential causes of declines. The team focuses on model-based monitoring to assess the impacts of climate change, emerging diseases, habitat restoration, and invasive species on amphibian communities.
Science and Products
Filter Total Items: 54
Linking variability in climate to wetland habitat suitability: Is it possible to forecast regional responses from simple climate measures?
Temporary wetlands have value to both ecological and social systems. Interactions between local climate and the surrounding landscape result in patterns of hydrology that are unique to temporary wetlands. These seasonal and annual fluctuations in wetland inundation contribute to community composition and richness. Thus, predicting wetland community responses to environmental change is tied to the
Authors
Davis C, Miller D, Evan H. Campbell Grant, Brian Halstead, Patrick M. Kleeman, Susan Walls, William Barichivich
Identifying management-relevant research priorities for responding to disease-associated amphibian declines
A research priority can be defined as a knowledge gap that, if resolved, identifies the optimal course of conservation action. We (a group of geographically distributed and multidisciplinary research scientists) used tools from nominal group theory and decision analysis to collaboratively identify and prioritize information needs within the context of disease-associated amphibian decline, in order
Authors
Evan H. Campbell Grant, M. J. Adams, Robert N. Fisher, Daniel A. Grear, Brian J. Halstead, Blake R. Hossack, Erin L. Muths, Katherine L. D. Richgels, Robin E. Russell, Kelly L. Smalling, J. Hardin Waddle, Susan C. Walls, C. LeAnn White
By
Ecosystems Mission Area, Water Resources Mission Area, Biological Threats and Invasive Species Research Program, Species Management Research Program, Eastern Ecological Science Center, Forest and Rangeland Ecosystem Science Center, Fort Collins Science Center, National Wildlife Health Center, New Jersey Water Science Center, Northern Rocky Mountain Science Center, Western Ecological Research Center (WERC), Wetland and Aquatic Research Center
Quantifying climate sensitivity and climate-driven change in North American amphibian communities
Changing climate will impact species’ ranges only when environmental variability directly impacts the demography of local populations. However, measurement of demographic responses to climate change has largely been limited to single species and locations. Here we show that amphibian communities are responsive to climatic variability, using >500,000 time-series observations for 81 species across 8
Authors
David A.W. Miller, Evan H. Campbell Grant, Erin L. Muths, Staci M. Amburgey, M. J. Adams, Maxwell B. Joseph, J. Hardin Waddle, Pieter T.J. Johnson, Maureen E. Ryan, Benedikt R. Schmidt, Daniel L. Calhoun, Courtney L. Davis, Robert N. Fisher, David M. Green, Blake R. Hossack, Tracy A.G. Rittenhouse, Susan C. Walls, Larissa L. Bailey, Sam S. Cruickshank, Gary M. Fellers, Thomas A. Gorman, Carola A. Haas, Ward Hughson, David S. Pilliod, Steven J. Price, Andrew M. Ray, Walter Sadinski, Daniel Saenz, William J. Barichivich, Adrianne B. Brand, Cheryl S. Brehme, Rosi Dagit, Katy S. Delaney, Brad M. Glorioso, Lee B. Kats, Patrick M. Kleeman, Christopher Pearl, Carlton J. Rochester, Seth P. D. Riley, Mark F. Roth, Brent Sigafus
By
Ecosystems Mission Area, Water Resources Mission Area, Species Management Research Program, Eastern Ecological Science Center, Forest and Rangeland Ecosystem Science Center, Fort Collins Science Center, John Wesley Powell Center for Analysis and Synthesis, Northern Rocky Mountain Science Center, South Atlantic Water Science Center (SAWSC), Southwest Biological Science Center, Upper Midwest Environmental Sciences Center, Western Ecological Research Center (WERC), Wetland and Aquatic Research Center
Coping with constraints: Achieving effective conservation with limited resources
Conservation resources have become increasingly limited and, along with social, cultural and political complexities, this shortfall frequently challenges effectiveness in conservation. Because conservation can be costly, efforts are often only initiated after a species has declined below a critical threshold and/or when statutory protection is mandated. However, implementing conservation proactive
Authors
Susan C. Walls
A new framework for analysing automated acoustic species detection data: Occupancy estimation and optimization of recordings post-processing
The development and use of automated species-detection technologies, such as acoustic recorders, for monitoring wildlife are rapidly expanding. Automated classification algorithms provide a cost- and time-effective means to process information-rich data, but often at the cost of additional detection errors. Appropriate methods are necessary to analyse such data while dealing with the different typ
Authors
Thierry A. Chambert, J. Hardin Waddle, David A.W. Miller, Susan C. Walls, James D. Nichols
The significant surface-water connectivity of "geographically isolated wetlands"
We evaluated the current literature, coupled with our collective research expertise, on surface-water connectivity of wetlands considered to be “geographically isolated” (sensu Tiner Wetlands 23:494–516, 2003a) to critically assess the scientific foundation of grouping wetlands based on the singular condition of being surrounded by uplands. The most recent research on wetlands considered to be “ge
Authors
Aram J.K. Calhoun, David M. Mushet, Laurie C. Alexander, Edward S. DeKeyser, Laurie Fowler, Charles R. Lane, Megan W. Lang, Mark C. Rains, Stephen Richter, Susan C. Walls
Identifying small depressional wetlands and using a topographic position index to infer hydroperiod regimes for pond-breeding amphibians
Small, seasonal pools and temporary ponds (
Authors
Jeffrey W. Riley, Daniel L. Calhoun, William J. Barichivich, Susan C. Walls
Structured decision making as a conservation tool for recovery planning of two endangered salamanders
At least one-third of all amphibian species face the threat of extinction, and current amphibian extinction rates are four orders of magnitude greater than background rates. Preventing extirpation often requires both ex situ (i.e., conservation breeding programs) and in situ strategies (i.e., protecting natural habitats). Flatwoods salamanders (Ambystoma bishopi and A. cingulatum) are protected un
Authors
Katy O'Donnell, Arianne F Messerman, William J. Barichivich, Raymond D. Semlitsch, Thomas A. Gorman, Harold G Mitchell, Nathan Allan, Dante B. Fenolio, Adam Green, Fred A. Johnson, Allison Keever, Mark Mandica, Julien Martin, Jana Mott, Terry Peacock, Joseph Reinman, Stephanie S. Romañach, Greg Titus, Conor P. McGowan, Susan C. Walls
Species interactions and the effects of climate variability on a wetland amphibian metacommunity
Disentangling the role that multiple interacting factors have on species responses to shifting climate poses a significant challenge. However, our ability to do so is of utmost importance to predict the effects of climate change on species distributions. We examined how populations of three species of wetland-breeding amphibians, which varied in life history requirements, responded to a six-year p
Authors
Courtney L. Davis, David A.W. Miller, Susan C. Walls, William J. Barichivich, Jeffrey W. Riley, Mary E. Brown
Life history plasticity does not confer resilience to environmental change in the mole salamander (Ambystoma talpoideum)
Plasticity in life history strategies can be advantageous for species that occupy spatially or temporally variable environments. We examined how phenotypic plasticity influences responses of the mole salamander, Ambystoma talpoideum, to disturbance events at the St. Marks National Wildlife Refuge (SMNWR), FL, USA from 2009 to 2014. We observed periods of extensive drought early in the study, in co
Authors
Courtney L. Davis, David A.W. Miller, Susan C. Walls, William J. Barichivich, Jeffrey W. Riley, Mary E. Brown
Book review: Behavioral ecology of the eastern red-backed salamander: 50 years of research
In commemoration of the 100th anniversary of the British Ecological Society, Sutherland et al. (2013) identified 100 questions of fundamental significance in “pure” (i.e., not applied) ecology. A somewhat unexpected outcome of these authors’ exercise was the realization that, after 100 years of comprehensive, intensive scientific research, there remained “profound knowledge
gaps” in ecology, such
Authors
Susan C. Walls, Joseph C. Mitchell
Overcoming challenges to the recovery of declining amphibian populations in the United States
The US Endangered Species Act of 1973 (ESA) affords many potential benefits to species threatened with extinction. However, most at-risk amphibians—one of the most imperiled vertebrate groups—remain unlisted under the provisions of the ESA, and many impediments to recovery exist for those species that have been listed. Of the 35 US amphibian species and distinct population segments (“taxa”) listed
Authors
Susan C. Walls, Lianne C. Ball, William J. Barichivich, Kenneth Dodd, Kevin M Enge, Thomas A. Gorman, Katy O'Donnell, John G Palis, Raymond D. Semlitsch
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Filter Total Items: 54
Linking variability in climate to wetland habitat suitability: Is it possible to forecast regional responses from simple climate measures?
Temporary wetlands have value to both ecological and social systems. Interactions between local climate and the surrounding landscape result in patterns of hydrology that are unique to temporary wetlands. These seasonal and annual fluctuations in wetland inundation contribute to community composition and richness. Thus, predicting wetland community responses to environmental change is tied to theAuthorsDavis C, Miller D, Evan H. Campbell Grant, Brian Halstead, Patrick M. Kleeman, Susan Walls, William BarichivichIdentifying management-relevant research priorities for responding to disease-associated amphibian declines
A research priority can be defined as a knowledge gap that, if resolved, identifies the optimal course of conservation action. We (a group of geographically distributed and multidisciplinary research scientists) used tools from nominal group theory and decision analysis to collaboratively identify and prioritize information needs within the context of disease-associated amphibian decline, in orderAuthorsEvan H. Campbell Grant, M. J. Adams, Robert N. Fisher, Daniel A. Grear, Brian J. Halstead, Blake R. Hossack, Erin L. Muths, Katherine L. D. Richgels, Robin E. Russell, Kelly L. Smalling, J. Hardin Waddle, Susan C. Walls, C. LeAnn WhiteByEcosystems Mission Area, Water Resources Mission Area, Biological Threats and Invasive Species Research Program, Species Management Research Program, Eastern Ecological Science Center, Forest and Rangeland Ecosystem Science Center, Fort Collins Science Center, National Wildlife Health Center, New Jersey Water Science Center, Northern Rocky Mountain Science Center, Western Ecological Research Center (WERC), Wetland and Aquatic Research CenterQuantifying climate sensitivity and climate-driven change in North American amphibian communities
Changing climate will impact species’ ranges only when environmental variability directly impacts the demography of local populations. However, measurement of demographic responses to climate change has largely been limited to single species and locations. Here we show that amphibian communities are responsive to climatic variability, using >500,000 time-series observations for 81 species across 8AuthorsDavid A.W. Miller, Evan H. Campbell Grant, Erin L. Muths, Staci M. Amburgey, M. J. Adams, Maxwell B. Joseph, J. Hardin Waddle, Pieter T.J. Johnson, Maureen E. Ryan, Benedikt R. Schmidt, Daniel L. Calhoun, Courtney L. Davis, Robert N. Fisher, David M. Green, Blake R. Hossack, Tracy A.G. Rittenhouse, Susan C. Walls, Larissa L. Bailey, Sam S. Cruickshank, Gary M. Fellers, Thomas A. Gorman, Carola A. Haas, Ward Hughson, David S. Pilliod, Steven J. Price, Andrew M. Ray, Walter Sadinski, Daniel Saenz, William J. Barichivich, Adrianne B. Brand, Cheryl S. Brehme, Rosi Dagit, Katy S. Delaney, Brad M. Glorioso, Lee B. Kats, Patrick M. Kleeman, Christopher Pearl, Carlton J. Rochester, Seth P. D. Riley, Mark F. Roth, Brent SigafusByEcosystems Mission Area, Water Resources Mission Area, Species Management Research Program, Eastern Ecological Science Center, Forest and Rangeland Ecosystem Science Center, Fort Collins Science Center, John Wesley Powell Center for Analysis and Synthesis, Northern Rocky Mountain Science Center, South Atlantic Water Science Center (SAWSC), Southwest Biological Science Center, Upper Midwest Environmental Sciences Center, Western Ecological Research Center (WERC), Wetland and Aquatic Research CenterCoping with constraints: Achieving effective conservation with limited resources
Conservation resources have become increasingly limited and, along with social, cultural and political complexities, this shortfall frequently challenges effectiveness in conservation. Because conservation can be costly, efforts are often only initiated after a species has declined below a critical threshold and/or when statutory protection is mandated. However, implementing conservation proactiveAuthorsSusan C. WallsA new framework for analysing automated acoustic species detection data: Occupancy estimation and optimization of recordings post-processing
The development and use of automated species-detection technologies, such as acoustic recorders, for monitoring wildlife are rapidly expanding. Automated classification algorithms provide a cost- and time-effective means to process information-rich data, but often at the cost of additional detection errors. Appropriate methods are necessary to analyse such data while dealing with the different typAuthorsThierry A. Chambert, J. Hardin Waddle, David A.W. Miller, Susan C. Walls, James D. NicholsThe significant surface-water connectivity of "geographically isolated wetlands"
We evaluated the current literature, coupled with our collective research expertise, on surface-water connectivity of wetlands considered to be “geographically isolated” (sensu Tiner Wetlands 23:494–516, 2003a) to critically assess the scientific foundation of grouping wetlands based on the singular condition of being surrounded by uplands. The most recent research on wetlands considered to be “geAuthorsAram J.K. Calhoun, David M. Mushet, Laurie C. Alexander, Edward S. DeKeyser, Laurie Fowler, Charles R. Lane, Megan W. Lang, Mark C. Rains, Stephen Richter, Susan C. WallsIdentifying small depressional wetlands and using a topographic position index to infer hydroperiod regimes for pond-breeding amphibians
Small, seasonal pools and temporary ponds (AuthorsJeffrey W. Riley, Daniel L. Calhoun, William J. Barichivich, Susan C. WallsStructured decision making as a conservation tool for recovery planning of two endangered salamanders
At least one-third of all amphibian species face the threat of extinction, and current amphibian extinction rates are four orders of magnitude greater than background rates. Preventing extirpation often requires both ex situ (i.e., conservation breeding programs) and in situ strategies (i.e., protecting natural habitats). Flatwoods salamanders (Ambystoma bishopi and A. cingulatum) are protected unAuthorsKaty O'Donnell, Arianne F Messerman, William J. Barichivich, Raymond D. Semlitsch, Thomas A. Gorman, Harold G Mitchell, Nathan Allan, Dante B. Fenolio, Adam Green, Fred A. Johnson, Allison Keever, Mark Mandica, Julien Martin, Jana Mott, Terry Peacock, Joseph Reinman, Stephanie S. Romañach, Greg Titus, Conor P. McGowan, Susan C. WallsSpecies interactions and the effects of climate variability on a wetland amphibian metacommunity
Disentangling the role that multiple interacting factors have on species responses to shifting climate poses a significant challenge. However, our ability to do so is of utmost importance to predict the effects of climate change on species distributions. We examined how populations of three species of wetland-breeding amphibians, which varied in life history requirements, responded to a six-year pAuthorsCourtney L. Davis, David A.W. Miller, Susan C. Walls, William J. Barichivich, Jeffrey W. Riley, Mary E. BrownLife history plasticity does not confer resilience to environmental change in the mole salamander (Ambystoma talpoideum)
Plasticity in life history strategies can be advantageous for species that occupy spatially or temporally variable environments. We examined how phenotypic plasticity influences responses of the mole salamander, Ambystoma talpoideum, to disturbance events at the St. Marks National Wildlife Refuge (SMNWR), FL, USA from 2009 to 2014. We observed periods of extensive drought early in the study, in coAuthorsCourtney L. Davis, David A.W. Miller, Susan C. Walls, William J. Barichivich, Jeffrey W. Riley, Mary E. BrownBook review: Behavioral ecology of the eastern red-backed salamander: 50 years of research
In commemoration of the 100th anniversary of the British Ecological Society, Sutherland et al. (2013) identified 100 questions of fundamental significance in “pure” (i.e., not applied) ecology. A somewhat unexpected outcome of these authors’ exercise was the realization that, after 100 years of comprehensive, intensive scientific research, there remained “profound knowledge gaps” in ecology, suchAuthorsSusan C. Walls, Joseph C. MitchellOvercoming challenges to the recovery of declining amphibian populations in the United States
The US Endangered Species Act of 1973 (ESA) affords many potential benefits to species threatened with extinction. However, most at-risk amphibians—one of the most imperiled vertebrate groups—remain unlisted under the provisions of the ESA, and many impediments to recovery exist for those species that have been listed. Of the 35 US amphibian species and distinct population segments (“taxa”) listedAuthorsSusan C. Walls, Lianne C. Ball, William J. Barichivich, Kenneth Dodd, Kevin M Enge, Thomas A. Gorman, Katy O'Donnell, John G Palis, Raymond D. Semlitsch - News