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
Trends in amphibian occupancy in the United States
Though a third of amphibian species worldwide are thought to be imperiled, existing assessments simply categorize extinction risk, providing little information on the rate of population losses. We conducted the first analysis of the rate of change in the probability that amphibians occupy ponds and other comparable habitat features across the United States. We found that overall occupancy by amphi
Authors
M. J. Adams, David A.W. Miller, Erin Muths, Paul Stephen Corn, Evan H. Campbell Grant, Larissa L. Bailey, Gary M. Fellers, Robert N. Fisher, Walter J. Sadinski, Hardin Waddle, Susan C. Walls
Influence of drought on salamander occupancy of isolated wetlands on the southeastern Coastal Plain of the United States
In the southeastern U.S., changes in temperature and precipitation over the last three decades have been the most dramatic in winter and spring seasons. Continuation of these trends could negatively impact pond-breeding amphibians, especially those that rely on winter and spring rains to fill seasonal wetlands, trigger breeding, and ensure reproductive success. From 2009 to 2012, we monitored Spri
Authors
Susan C. Walls, William J. Barichivich, Mary E. Brown, David E. Scott, Blake R. Hossack
Drought, deluge and declines: the impact of precipitation extremes on amphibians in a changing climate
The Class Amphibia is one of the most severely impacted taxa in an on-going global biodiversity crisis. Because amphibian reproduction is tightly associated with the presence of water, climatic changes that affect water availability pose a particularly menacing threat to both aquatic and terrestrial-breeding amphibians. We explore the impacts that one facet of climate change—that of extreme variat
Authors
Susan C. Walls, William J. Barichivich, Mary E. Brown
Ambystoma talpoideum (Mole Salamander). Oviposition mode and timing
No abstract available.
Authors
S.C. Walls, W.J. Barichivich, M.E. Brown
Estimating occupancy dynamics in an anuran assemblage from Louisiana, USA
Effective monitoring programs are designed to track changes in the distribution, occurrence, and abundance of species. We developed an extension of Royle and Kéry's (2007) single species model to estimate simultaneously temporal changes in probabilities of detection, occupancy, colonization, extinction, and species turnover using data on calling anuran amphibians, collected from 2002 to 2006 in th
Authors
Susan C. Walls, J. Hardin Waddle, Robert M. Dorazio
Effects of conservation practices on wetland ecosystem services in the Mississippi Alluvial Valley
Restoration of wetland ecosystems is an important priority for many state and federal agencies, as well as nongovernmental conservation organizations. The historic conversion of wetlands in the Mississippi Alluvial Valley (MAV) has resulted in large‐scale implementation of a variety of conservation practices designed to restore and enhance wetland ecosystem services. As a consequence, the effectiv
Authors
Stephen Faulkner, Wylie C. Barrow, Bob Keeland, Susan Walls, David Telesco
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 estimating pa
Authors
J. Hardin Waddle, Robert M. Dorazio, Susan C. Walls, Kenneth G. Rice, Jeff Beauchamp, Melinda J. Schuman, Frank J. Mazzotti
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, predomin
Authors
Stephen P. Faulkner, Michael J. Baldwin, Wylie C. Barrow, Hardin Waddle, Bobby D. Keeland, Susan C. Walls, Dale James, Tom Moorman
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 and communit
Authors
Andrew R. Blaustein, Susan C. Walls, Betsy A. Bancroft, Joshua J. Lawler, Catherine L. Searle, Stephanie S. Gervasi
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 elevations,
Authors
Susan C. Walls
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 understanding. I
Authors
Susan C. Walls
Auditory monitoring of anuran populations: Chapter 16
No abstract available.
Authors
Michael E Dorcas, Steven J. Price, Susan C. Walls, William J. Barichivich
Science and Products
Filter Total Items: 55
Trends in amphibian occupancy in the United States
Though a third of amphibian species worldwide are thought to be imperiled, existing assessments simply categorize extinction risk, providing little information on the rate of population losses. We conducted the first analysis of the rate of change in the probability that amphibians occupy ponds and other comparable habitat features across the United States. We found that overall occupancy by amphi
Authors
M. J. Adams, David A.W. Miller, Erin Muths, Paul Stephen Corn, Evan H. Campbell Grant, Larissa L. Bailey, Gary M. Fellers, Robert N. Fisher, Walter J. Sadinski, Hardin Waddle, Susan C. Walls
Influence of drought on salamander occupancy of isolated wetlands on the southeastern Coastal Plain of the United States
In the southeastern U.S., changes in temperature and precipitation over the last three decades have been the most dramatic in winter and spring seasons. Continuation of these trends could negatively impact pond-breeding amphibians, especially those that rely on winter and spring rains to fill seasonal wetlands, trigger breeding, and ensure reproductive success. From 2009 to 2012, we monitored Spri
Authors
Susan C. Walls, William J. Barichivich, Mary E. Brown, David E. Scott, Blake R. Hossack
Drought, deluge and declines: the impact of precipitation extremes on amphibians in a changing climate
The Class Amphibia is one of the most severely impacted taxa in an on-going global biodiversity crisis. Because amphibian reproduction is tightly associated with the presence of water, climatic changes that affect water availability pose a particularly menacing threat to both aquatic and terrestrial-breeding amphibians. We explore the impacts that one facet of climate change—that of extreme variat
Authors
Susan C. Walls, William J. Barichivich, Mary E. Brown
Ambystoma talpoideum (Mole Salamander). Oviposition mode and timing
No abstract available.
Authors
S.C. Walls, W.J. Barichivich, M.E. Brown
Estimating occupancy dynamics in an anuran assemblage from Louisiana, USA
Effective monitoring programs are designed to track changes in the distribution, occurrence, and abundance of species. We developed an extension of Royle and Kéry's (2007) single species model to estimate simultaneously temporal changes in probabilities of detection, occupancy, colonization, extinction, and species turnover using data on calling anuran amphibians, collected from 2002 to 2006 in th
Authors
Susan C. Walls, J. Hardin Waddle, Robert M. Dorazio
Effects of conservation practices on wetland ecosystem services in the Mississippi Alluvial Valley
Restoration of wetland ecosystems is an important priority for many state and federal agencies, as well as nongovernmental conservation organizations. The historic conversion of wetlands in the Mississippi Alluvial Valley (MAV) has resulted in large‐scale implementation of a variety of conservation practices designed to restore and enhance wetland ecosystem services. As a consequence, the effectiv
Authors
Stephen Faulkner, Wylie C. Barrow, Bob Keeland, Susan Walls, David Telesco
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 estimating pa
Authors
J. Hardin Waddle, Robert M. Dorazio, Susan C. Walls, Kenneth G. Rice, Jeff Beauchamp, Melinda J. Schuman, Frank J. Mazzotti
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, predomin
Authors
Stephen P. Faulkner, Michael J. Baldwin, Wylie C. Barrow, Hardin Waddle, Bobby D. Keeland, Susan C. Walls, Dale James, Tom Moorman
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 and communit
Authors
Andrew R. Blaustein, Susan C. Walls, Betsy A. Bancroft, Joshua J. Lawler, Catherine L. Searle, Stephanie S. Gervasi
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 elevations,
Authors
Susan C. Walls
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 understanding. I
Authors
Susan C. Walls
Auditory monitoring of anuran populations: Chapter 16
No abstract available.
Authors
Michael E Dorcas, Steven J. Price, Susan C. Walls, William J. Barichivich