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: 61
Regional estimates of ecological services derived from U.S. Department of Agriculture conservation programs in the Mississippi Alluvial Valley Regional estimates of ecological services derived from U.S. Department of Agriculture conservation programs in the Mississippi Alluvial Valley
The Mississippi Alluvial Valley (MAV) is the Nation?s largest floodplain and this once predominantly forested ecosystem provided significant habitat for a diverse flora and fauna, sequestered carbon in trees and soil, and stored floodwater, sediments, and nutrients within the floodplain. This landscape has been substantially altered by the conversion of nearly 75% of the riparian forests
Authors
Stephen Faulkner, Michael J. Baldwin, Wylie C. Barrow, Hardin Waddle, Bobby Keeland, Susan Walls, Dale James, Tom Moorman
Direct and indirect effects of climate change on amphibian populations Direct and indirect effects of climate change on amphibian populations
As part of an overall decline in biodiversity, populations of many organisms are declining and species are being lost at unprecedented rates around the world. This includes many populations and species of amphibians. Although numerous factors are affecting amphibian populations, we show potential direct and indirect effects of climate change on amphibians at the individual, population...
Authors
Andrew Blaustein, Susan C. Walls, Betsy Bancroft, Joshua Lawler, Catherine Searle, Stephanie Gervasi
A new parameterization for estimating co‐occurrence of interacting species A new parameterization for estimating co‐occurrence of interacting species
Models currently used to estimate patterns of species co‐occurrence while accounting for errors in detection of species can be difficult to fit when the effects of covariates on species occurrence probabilities are included. The source of the estimation problems is the particular parameterization used to specify species co‐occurrence probability. We develop a new parameterization for...
Authors
J. Waddle, Robert M. Dorazio, Susan Walls, Kenneth Rice, Jeff Beauchamp, Melinda J. Schuman, Frank J. Mazzotti
The role of climate in the dynamics of a hybrid zone in Appalachian salamanders The role of climate in the dynamics of a hybrid zone in Appalachian salamanders
I examined the potential influence of climate change on the dynamics of a previously studied hybrid zone between a pair of terrestrial salamanders at the Coweeta Hydrologic Laboratory, U.S. Forest Service, in the Nantahala Mountains of North Carolina, USA. A 16-year study led by Nelson G. Hairston, Sr. revealed that Plethodon teyahalee and Plethodon shermani hybridized at intermediate...
Authors
Susan Walls
Book review: The ecology and behavior of amphibians Book review: The ecology and behavior of amphibians
This state‐of‐the‐art book has made its timely emergence amid a crisis of global magnitude: that of population declines, range reductions, and extinctions of numerous species of amphibians. A clear understanding of the fundamental concepts in amphibian biology is crucial to the success of any conservation effort. This volume compiles the information necessary to acquire that basic...
Authors
Susan Walls
Auditory monitoring of anuran populations: Chapter 16 Auditory monitoring of anuran populations: Chapter 16
No abstract available.
Authors
Michael Dorcas, Steven Price, Susan Walls, William Barichivich
Widespread occurrence of the amphibian chytrid fungus Batrachochytrium dendrobatidis in the southeastern USA Widespread occurrence of the amphibian chytrid fungus Batrachochytrium dendrobatidis in the southeastern USA
From 1999 to 2006, we sampled >1200 amphibians for the fungal pathogen Batrachochytnum dendrobatidis (Bd) at 30 sites in the southeastern USA. Using histological techniques or PCR assays, we detected chytrid infection in 10 species of aquatic-breeding amphibians in 6 states. The prevalence of chytrid infection was 17.8% for samples of postmetamorphic amphibians examined using skin swab...
Authors
B.B. Rothermel, S.C. Walls, J.C. Mitchell, C.K. Dodd, L.K. Irwin, D. Green, Victoria Vazquez, James Petranka, Dirk Stevenson
Occurrence of oral deformities in larval anurans Occurrence of oral deformities in larval anurans
We quantified deformities in the marginal papillae, tooth rows, and jaw sheaths of tadpoles from 13 population samples representing three families and 11 sites in the southeastern United States. Oral deformities were observed in all samples and in 13.5-98% of the specimens per sample. Batrachochytrium dendrobatidis (chytrid) infections were detected in three samples. There was high...
Authors
D.L. Drake, R. Altig, J.B. Grace, S.C. Walls
Habitat associations of chorusing anurans in the Lower Mississippi River Alluvial valley Habitat associations of chorusing anurans in the Lower Mississippi River Alluvial valley
Amphibian populations have declined worldwide. To pursue conservation efforts adequately, land managers need more information concerning amphibian habitat requirements. To address this need, we examined relationships between anurans and habitat characteristics of wetlands in the Lower Mississippi River Alluvial Valley (LMAV). We surveyed chorusing anurans in 31 wetlands in 2000 and 28...
Authors
J.S. Lichtenberg, S.L. King, J.B. Grace, S.C. Walls
The Amphibian Research and Monitoring Initiative (ARMI): 5-year report The Amphibian Research and Monitoring Initiative (ARMI): 5-year report
The Amphibian Research and Monitoring Initiative (ARMI) is an innovative, multidisciplinary program that began in 2000 in response to a congressional directive for the Department of the Interior to address the issue of amphibian declines in the United States. ARMI’s formulation was cross-disciplinary, integrating U.S. Geological Survey scientists from Biology, Water, and Geography to...
Authors
Erin Muths, Alisa Gallant, Evan H. Campbell Grant, William Battaglin, David Green, Jennifer Staiger, Susan C. Walls, Margaret Gunzburger, Rick Kearney
Amphibian Research and Monitoring Initiative (ARMI): A successful start to a national program in the United States Amphibian Research and Monitoring Initiative (ARMI): A successful start to a national program in the United States
Most research to assess amphibian declines has focused on local-scale projects on one or a few species. The Amphibian Research and Monitoring Initiative (ARMI) is a national program in the United States mandated by congressional directive and implemented by the U.S. Department of the Interior (specifically the U.S. Geological Survey, USGS). Program goals are to monitor changes in...
Authors
Erin Muths, Robin Jung, Larissa Bailey, M. Adams, P. Corn, C. Dodd, Gary Fellers, Walter Sadinski, Cecil Schwalbe, Susan Walls, Robert Fisher, Alisa Gallant, William Battaglin, D. Green
Interspecific differences in susceptibility to competition and predation in a species-pair of larval amphibians Interspecific differences in susceptibility to competition and predation in a species-pair of larval amphibians
Fundamental issues in the study of predator-prey interactions include addressing how prey coexist with their predators and, moreover, whether predators promote coexistence among competing prey. We conducted a series of laboratory experiments with a freshwater assemblage consisting of two predators that differed in their foraging modes (a crayfish, Procambarus sp., and the western...
Authors
Susan Walls, David Taylor, Charlena Wilson
Science and Products
Filter Total Items: 61
Regional estimates of ecological services derived from U.S. Department of Agriculture conservation programs in the Mississippi Alluvial Valley Regional estimates of ecological services derived from U.S. Department of Agriculture conservation programs in the Mississippi Alluvial Valley
The Mississippi Alluvial Valley (MAV) is the Nation?s largest floodplain and this once predominantly forested ecosystem provided significant habitat for a diverse flora and fauna, sequestered carbon in trees and soil, and stored floodwater, sediments, and nutrients within the floodplain. This landscape has been substantially altered by the conversion of nearly 75% of the riparian forests
Authors
Stephen Faulkner, Michael J. Baldwin, Wylie C. Barrow, Hardin Waddle, Bobby Keeland, Susan Walls, Dale James, Tom Moorman
Direct and indirect effects of climate change on amphibian populations Direct and indirect effects of climate change on amphibian populations
As part of an overall decline in biodiversity, populations of many organisms are declining and species are being lost at unprecedented rates around the world. This includes many populations and species of amphibians. Although numerous factors are affecting amphibian populations, we show potential direct and indirect effects of climate change on amphibians at the individual, population...
Authors
Andrew Blaustein, Susan C. Walls, Betsy Bancroft, Joshua Lawler, Catherine Searle, Stephanie Gervasi
A new parameterization for estimating co‐occurrence of interacting species A new parameterization for estimating co‐occurrence of interacting species
Models currently used to estimate patterns of species co‐occurrence while accounting for errors in detection of species can be difficult to fit when the effects of covariates on species occurrence probabilities are included. The source of the estimation problems is the particular parameterization used to specify species co‐occurrence probability. We develop a new parameterization for...
Authors
J. Waddle, Robert M. Dorazio, Susan Walls, Kenneth Rice, Jeff Beauchamp, Melinda J. Schuman, Frank J. Mazzotti
The role of climate in the dynamics of a hybrid zone in Appalachian salamanders The role of climate in the dynamics of a hybrid zone in Appalachian salamanders
I examined the potential influence of climate change on the dynamics of a previously studied hybrid zone between a pair of terrestrial salamanders at the Coweeta Hydrologic Laboratory, U.S. Forest Service, in the Nantahala Mountains of North Carolina, USA. A 16-year study led by Nelson G. Hairston, Sr. revealed that Plethodon teyahalee and Plethodon shermani hybridized at intermediate...
Authors
Susan Walls
Book review: The ecology and behavior of amphibians Book review: The ecology and behavior of amphibians
This state‐of‐the‐art book has made its timely emergence amid a crisis of global magnitude: that of population declines, range reductions, and extinctions of numerous species of amphibians. A clear understanding of the fundamental concepts in amphibian biology is crucial to the success of any conservation effort. This volume compiles the information necessary to acquire that basic...
Authors
Susan Walls
Auditory monitoring of anuran populations: Chapter 16 Auditory monitoring of anuran populations: Chapter 16
No abstract available.
Authors
Michael Dorcas, Steven Price, Susan Walls, William Barichivich
Widespread occurrence of the amphibian chytrid fungus Batrachochytrium dendrobatidis in the southeastern USA Widespread occurrence of the amphibian chytrid fungus Batrachochytrium dendrobatidis in the southeastern USA
From 1999 to 2006, we sampled >1200 amphibians for the fungal pathogen Batrachochytnum dendrobatidis (Bd) at 30 sites in the southeastern USA. Using histological techniques or PCR assays, we detected chytrid infection in 10 species of aquatic-breeding amphibians in 6 states. The prevalence of chytrid infection was 17.8% for samples of postmetamorphic amphibians examined using skin swab...
Authors
B.B. Rothermel, S.C. Walls, J.C. Mitchell, C.K. Dodd, L.K. Irwin, D. Green, Victoria Vazquez, James Petranka, Dirk Stevenson
Occurrence of oral deformities in larval anurans Occurrence of oral deformities in larval anurans
We quantified deformities in the marginal papillae, tooth rows, and jaw sheaths of tadpoles from 13 population samples representing three families and 11 sites in the southeastern United States. Oral deformities were observed in all samples and in 13.5-98% of the specimens per sample. Batrachochytrium dendrobatidis (chytrid) infections were detected in three samples. There was high...
Authors
D.L. Drake, R. Altig, J.B. Grace, S.C. Walls
Habitat associations of chorusing anurans in the Lower Mississippi River Alluvial valley Habitat associations of chorusing anurans in the Lower Mississippi River Alluvial valley
Amphibian populations have declined worldwide. To pursue conservation efforts adequately, land managers need more information concerning amphibian habitat requirements. To address this need, we examined relationships between anurans and habitat characteristics of wetlands in the Lower Mississippi River Alluvial Valley (LMAV). We surveyed chorusing anurans in 31 wetlands in 2000 and 28...
Authors
J.S. Lichtenberg, S.L. King, J.B. Grace, S.C. Walls
The Amphibian Research and Monitoring Initiative (ARMI): 5-year report The Amphibian Research and Monitoring Initiative (ARMI): 5-year report
The Amphibian Research and Monitoring Initiative (ARMI) is an innovative, multidisciplinary program that began in 2000 in response to a congressional directive for the Department of the Interior to address the issue of amphibian declines in the United States. ARMI’s formulation was cross-disciplinary, integrating U.S. Geological Survey scientists from Biology, Water, and Geography to...
Authors
Erin Muths, Alisa Gallant, Evan H. Campbell Grant, William Battaglin, David Green, Jennifer Staiger, Susan C. Walls, Margaret Gunzburger, Rick Kearney
Amphibian Research and Monitoring Initiative (ARMI): A successful start to a national program in the United States Amphibian Research and Monitoring Initiative (ARMI): A successful start to a national program in the United States
Most research to assess amphibian declines has focused on local-scale projects on one or a few species. The Amphibian Research and Monitoring Initiative (ARMI) is a national program in the United States mandated by congressional directive and implemented by the U.S. Department of the Interior (specifically the U.S. Geological Survey, USGS). Program goals are to monitor changes in...
Authors
Erin Muths, Robin Jung, Larissa Bailey, M. Adams, P. Corn, C. Dodd, Gary Fellers, Walter Sadinski, Cecil Schwalbe, Susan Walls, Robert Fisher, Alisa Gallant, William Battaglin, D. Green
Interspecific differences in susceptibility to competition and predation in a species-pair of larval amphibians Interspecific differences in susceptibility to competition and predation in a species-pair of larval amphibians
Fundamental issues in the study of predator-prey interactions include addressing how prey coexist with their predators and, moreover, whether predators promote coexistence among competing prey. We conducted a series of laboratory experiments with a freshwater assemblage consisting of two predators that differed in their foraging modes (a crayfish, Procambarus sp., and the western...
Authors
Susan Walls, David Taylor, Charlena Wilson