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
Geographically isolated wetlands: Rethinking a misnomer Geographically isolated wetlands: Rethinking a misnomer
We explore the category “geographically isolated wetlands” (GIWs; i.e., wetlands completely surrounded by uplands at the local scale) as used in the wetland sciences. As currently used, the GIW category (1) hampers scientific efforts by obscuring important hydrological and ecological differences among multiple wetland functional types, (2) aggregates wetlands in a manner not reflective...
Authors
David Mushet, Aram Calhoun, Laurie C. Alexander, Matthew Cohen, Edward S. DeKeyser, Laurie Fowler, Charles R. Lane, Megan Lang, Mark Rains, Susan Walls
Identifying monitoring gaps for amphibian populations in a North American biodiversity hotspot, the southeastern USA Identifying monitoring gaps for amphibian populations in a North American biodiversity hotspot, the southeastern USA
I review the primary literature to ascertain the status of amphibian monitoring efforts in the southeastern USA, a “hotspot” for biodiversity in North America. This effort revealed taxonomic, geographic and ecological disparities in studies of amphibian populations in this region. Of the species of anurans and caudates known to occur in the Southeast, 73.8 and 33.3 %, respectively, have...
Authors
Susan Walls
Anuran site occupancy and species richness as tools for evaluating restoration of a hydrologically-modified landscape Anuran site occupancy and species richness as tools for evaluating restoration of a hydrologically-modified landscape
A fundamental goal of wetland restoration is to reinstate pre-disturbance hydrological conditions to degraded landscapes, facilitating recolonization by native species and the production of resilient, functional ecosystems. To evaluate restoration success, baseline conditions need to be determined and a reference target needs to be established that will serve as an ecological blueprint...
Authors
Susan Walls, J. Waddle, William Barichivich, Ian Bartoszek, Mary E. Brown, J. Hefner, Melinda J. Schuman
Wetland Reserve Program enhances site occupancy and species richness in assemblages of anuran amphibians in the Mississippi Alluvial Valley, USA Wetland Reserve Program enhances site occupancy and species richness in assemblages of anuran amphibians in the Mississippi Alluvial Valley, USA
We measured amphibian habitat use to quantify the effectiveness of conservation practices implemented under the Wetland Reserve Program (WRP), an initiative of the U.S. Department of Agriculture’s Natural Resources Conservation Service. From February to June 2007, we quantified calling male anurans in cultivated cropland, former cultivated cropland restored through the WRP, and mature...
Authors
Susan C. Walls, J. Hardin Waddle, Stephen Faulkner
Nest site selection by diamond-backed terrapins (Malaclemys terrapin) on a Mid-Atlantic Barrier Island Nest site selection by diamond-backed terrapins (Malaclemys terrapin) on a Mid-Atlantic Barrier Island
We scored 48 Malaclemys terrapin nests destroyed by raccoons on Fisherman Island, Virginia, for the presence or absence of tree canopy, shrub canopy, no canopy, bare sand, grass cover, and herbaceous cover. Significantly more nests than expected were found in the open with no vegetation cover and observed distances of predator-destroyed nests from the edge of the nearest habitat island...
Authors
Joseph Mitchell, Susan C. Walls
Variation in salinity tolerance among larval anurans: implications for community composition and the spread of an invasive, non-native species Variation in salinity tolerance among larval anurans: implications for community composition and the spread of an invasive, non-native species
Amphibians in freshwater coastal wetlands periodically experience acute exposure to salinity from hurricane-related overwash events, as well as chronic exposure associated with rising sea levels. In a comparative experimental approach, we examined whether seven species of anuran amphibians vary in their tolerance to changes in salinity. In a laboratory study, we exposed larval Hyla...
Authors
Mary Brown, Susan C. Walls
Trends in amphibian occupancy in the United States 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...
Authors
M. Adams, David A.W. Miller, Erin Muths, Paul Stephen Corn, Evan H. Campbell Grant, Larissa L. Bailey, Gary Fellers, Robert Fisher, Walter Sadinski, Hardin Waddle, Susan C. Walls
Influence of drought on salamander occupancy of isolated wetlands on the southeastern Coastal Plain of the United States 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...
Authors
Susan C. Walls, William Barichivich, Mary Brown, David E. Scott, Blake Hossack
Drought, deluge and declines: the impact of precipitation extremes on amphibians in a changing climate 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...
Authors
Susan C. Walls, William Barichivich, Mary Brown
Ambystoma talpoideum (Mole Salamander). Oviposition mode and timing 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 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...
Authors
Susan C. Walls, J. Hardin Waddle, Robert Dorazio
Effects of conservation practices on wetland ecosystem services in the Mississippi Alluvial Valley 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...
Authors
Stephen Faulkner, Wylie C. Barrow, Bob Keeland, Susan Walls, David Telesco
Science and Products
Filter Total Items: 61
Geographically isolated wetlands: Rethinking a misnomer Geographically isolated wetlands: Rethinking a misnomer
We explore the category “geographically isolated wetlands” (GIWs; i.e., wetlands completely surrounded by uplands at the local scale) as used in the wetland sciences. As currently used, the GIW category (1) hampers scientific efforts by obscuring important hydrological and ecological differences among multiple wetland functional types, (2) aggregates wetlands in a manner not reflective...
Authors
David Mushet, Aram Calhoun, Laurie C. Alexander, Matthew Cohen, Edward S. DeKeyser, Laurie Fowler, Charles R. Lane, Megan Lang, Mark Rains, Susan Walls
Identifying monitoring gaps for amphibian populations in a North American biodiversity hotspot, the southeastern USA Identifying monitoring gaps for amphibian populations in a North American biodiversity hotspot, the southeastern USA
I review the primary literature to ascertain the status of amphibian monitoring efforts in the southeastern USA, a “hotspot” for biodiversity in North America. This effort revealed taxonomic, geographic and ecological disparities in studies of amphibian populations in this region. Of the species of anurans and caudates known to occur in the Southeast, 73.8 and 33.3 %, respectively, have...
Authors
Susan Walls
Anuran site occupancy and species richness as tools for evaluating restoration of a hydrologically-modified landscape Anuran site occupancy and species richness as tools for evaluating restoration of a hydrologically-modified landscape
A fundamental goal of wetland restoration is to reinstate pre-disturbance hydrological conditions to degraded landscapes, facilitating recolonization by native species and the production of resilient, functional ecosystems. To evaluate restoration success, baseline conditions need to be determined and a reference target needs to be established that will serve as an ecological blueprint...
Authors
Susan Walls, J. Waddle, William Barichivich, Ian Bartoszek, Mary E. Brown, J. Hefner, Melinda J. Schuman
Wetland Reserve Program enhances site occupancy and species richness in assemblages of anuran amphibians in the Mississippi Alluvial Valley, USA Wetland Reserve Program enhances site occupancy and species richness in assemblages of anuran amphibians in the Mississippi Alluvial Valley, USA
We measured amphibian habitat use to quantify the effectiveness of conservation practices implemented under the Wetland Reserve Program (WRP), an initiative of the U.S. Department of Agriculture’s Natural Resources Conservation Service. From February to June 2007, we quantified calling male anurans in cultivated cropland, former cultivated cropland restored through the WRP, and mature...
Authors
Susan C. Walls, J. Hardin Waddle, Stephen Faulkner
Nest site selection by diamond-backed terrapins (Malaclemys terrapin) on a Mid-Atlantic Barrier Island Nest site selection by diamond-backed terrapins (Malaclemys terrapin) on a Mid-Atlantic Barrier Island
We scored 48 Malaclemys terrapin nests destroyed by raccoons on Fisherman Island, Virginia, for the presence or absence of tree canopy, shrub canopy, no canopy, bare sand, grass cover, and herbaceous cover. Significantly more nests than expected were found in the open with no vegetation cover and observed distances of predator-destroyed nests from the edge of the nearest habitat island...
Authors
Joseph Mitchell, Susan C. Walls
Variation in salinity tolerance among larval anurans: implications for community composition and the spread of an invasive, non-native species Variation in salinity tolerance among larval anurans: implications for community composition and the spread of an invasive, non-native species
Amphibians in freshwater coastal wetlands periodically experience acute exposure to salinity from hurricane-related overwash events, as well as chronic exposure associated with rising sea levels. In a comparative experimental approach, we examined whether seven species of anuran amphibians vary in their tolerance to changes in salinity. In a laboratory study, we exposed larval Hyla...
Authors
Mary Brown, Susan C. Walls
Trends in amphibian occupancy in the United States 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...
Authors
M. Adams, David A.W. Miller, Erin Muths, Paul Stephen Corn, Evan H. Campbell Grant, Larissa L. Bailey, Gary Fellers, Robert Fisher, Walter Sadinski, Hardin Waddle, Susan C. Walls
Influence of drought on salamander occupancy of isolated wetlands on the southeastern Coastal Plain of the United States 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...
Authors
Susan C. Walls, William Barichivich, Mary Brown, David E. Scott, Blake Hossack
Drought, deluge and declines: the impact of precipitation extremes on amphibians in a changing climate 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...
Authors
Susan C. Walls, William Barichivich, Mary Brown
Ambystoma talpoideum (Mole Salamander). Oviposition mode and timing 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 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...
Authors
Susan C. Walls, J. Hardin Waddle, Robert Dorazio
Effects of conservation practices on wetland ecosystem services in the Mississippi Alluvial Valley 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...
Authors
Stephen Faulkner, Wylie C. Barrow, Bob Keeland, Susan Walls, David Telesco