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: 55
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-PCR assays
Authors
B.B. Rothermel, S.C. Walls, J.C. Mitchell, C. K. Dodd, L.K. Irwin, D. E. Green, Victoria M. Vazquez, James W. Petranka, Dirk J. Stevenson
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 variability amo
Authors
D.L. Drake, R. Altig, J.B. Grace, S.C. Walls
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 wetlands in
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) 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 develop a cou
Authors
Erin Muths, Alisa L. Gallant, Evan H. Campbell Grant, William A. Battaglin, David E. Green, Jennifer S. Staiger, Susan C. Walls, Margaret S. Gunzburger, Rick F. Kearney
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 populations of am
Authors
Gary M. Fellers, Erin Muths, C. Kenneth Dodd, D. Earl Green, William A. Battaglin, P. Stephen Corn, M. J. Adams, Alisa L. Gallant, Robert N. Fisher, Cecil R. Schwalbe, Larissa L. Bailey, Walter J. Sadinski, Robin E. Jung, Susan C. Walls
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 mosquitofish, Gam
Authors
Susan C. Walls, David G. Taylor, Charlena M. Wilson
The effect of community composition on persistence of prey with their predators in an assemblage of pond-breeding amphibians
We examined whether the species composition of a community influences the persistence of larval Ambystoma maculatum in assemblages composed of two larger intraguild predators (A. opacum and A. jeffersonianum) and an alternative prey species (tadpoles of Rana sylvatica). We predicted a priori that A. maculatum would have higher survival in more diverse communities containing alternative species of
Authors
S.C. Walls, M.C. Williams
Science and Products
Filter Total Items: 55
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-PCR assays
Authors
B.B. Rothermel, S.C. Walls, J.C. Mitchell, C. K. Dodd, L.K. Irwin, D. E. Green, Victoria M. Vazquez, James W. Petranka, Dirk J. Stevenson
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 variability amo
Authors
D.L. Drake, R. Altig, J.B. Grace, S.C. Walls
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 wetlands in
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) 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 develop a cou
Authors
Erin Muths, Alisa L. Gallant, Evan H. Campbell Grant, William A. Battaglin, David E. Green, Jennifer S. Staiger, Susan C. Walls, Margaret S. Gunzburger, Rick F. Kearney
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 populations of am
Authors
Gary M. Fellers, Erin Muths, C. Kenneth Dodd, D. Earl Green, William A. Battaglin, P. Stephen Corn, M. J. Adams, Alisa L. Gallant, Robert N. Fisher, Cecil R. Schwalbe, Larissa L. Bailey, Walter J. Sadinski, Robin E. Jung, Susan C. Walls
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 mosquitofish, Gam
Authors
Susan C. Walls, David G. Taylor, Charlena M. Wilson
The effect of community composition on persistence of prey with their predators in an assemblage of pond-breeding amphibians
We examined whether the species composition of a community influences the persistence of larval Ambystoma maculatum in assemblages composed of two larger intraguild predators (A. opacum and A. jeffersonianum) and an alternative prey species (tadpoles of Rana sylvatica). We predicted a priori that A. maculatum would have higher survival in more diverse communities containing alternative species of
Authors
S.C. Walls, M.C. Williams