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
Vulnerability of Mole Skinks to Sea-Level Rise
Mole skinks that occur on Florida’s islands rely on sand beaches, beach berms, and dunes, making them particularly vulnerable to sea level rise and storm surge. USGS researchers predicted the impacts of sea level rise and storm surge on habitat for the Florida Keys mole skink ( Plestiodon egregius egregius), the Cedar Key mole skink ( P. e. insularis), and the Egmont Key mole skink (known from a...
Predicting Sea-Level Rise Impacts to Barrier Island Habitats
Researchers at WARC are determining if temporal mismatches between digital elevation models and land cover data can impact estimates of inundation of beach habitat for barrier islands and low-lying beaches off the Gulf Coast of Florida.
Population Persistence of the Ornate Chorus Frog Across Its Distribution
The ornate chorus frog, once common throughout its range, appears to be experiencing population declines. USGS has partnered with the Florida Fish and Wildlife Conservation Commission to assess the ornate chorus frog population status across its distribution.
Sea-Level Rise and Florida’s Island Biodiversity
While islands are some of the most biodiverse places on earth, they are also among the most threatened. Researchers from WARC and Florida Fish and Wildlife Conservation Commission are assessing the vulnerability of Florida’s coastal islands to inundation from sea-level rise and estimating potential loss of the terrestrial biodiversity on Florida’s islands.
How Wildlife Respond to Tropical Cyclones: Short-Term Tactics and Long-Term Impacts
USGS is collaborating with the University of Florida to describe the diverse and fascinating tactics demonstrated by wildlife to survive tropical cyclones, which can aid in understanding the impact environmental change is having on wildlife and provide insights into how those impacts may be mitigated.
Informing Future Condition Scenario Planning for Habitat Specialists of the Imperiled Pine Rockland Ecosystem of South Florida
South Florida's pine rockland ecosystem represents less than 3% of its original extent. This project will evaluate habitat conditions for two pine rockland snake species to develop future habitat condition scenarios for Species Status Assessments.
Salamander species in headwater streams on state and federal public lands in the eastern United States Salamander species in headwater streams on state and federal public lands in the eastern United States
This dataset includes stream and species data collected in headwater streams on public lands throughout the eastern United States. Data were collected to inform updated species range maps and provide data for large-scale modeling of species ranges using multiple data types. All salamander species encountered are included in the dataset.
Range-wide probability of persistence of Ornate Chorus Frog populations and a habitat suitability map Range-wide probability of persistence of Ornate Chorus Frog populations and a habitat suitability map
Data include the probability of persistence of 407 Ornate Chorus Frog (Pseudacris ornata) populations across the distribution, as well as the mean habitat suitability, mean winter precipitation, and proportion of the surface that is impervious within each buffered population. Data also include the probability of persistence of Ornate Chorus Frog populations when different buffer sizes...
Sea level rise and Florida’s insular vertebrate biodiversity: predictions of island inundation and the number of coastal species vulnerable to sea level rise Sea level rise and Florida’s insular vertebrate biodiversity: predictions of island inundation and the number of coastal species vulnerable to sea level rise
Data include the proportion of Florida's coastal islands (n = 2504) that are projected to be inundated from sea level rise (SLR), as well as a prediction of the depth of SLR that would inundate each island. Data include the proportion of Florida's islands predicted to still be above water in 2100 that are currently human-modified. Data also include a count of the number of terrestrial...
Insular mole skinks: Area of habitat still above water given projected sea level rise and proportion of habitat at risk of storm surge in the Florida Keys, Cedar Keys, and Egmont Key, Florida Insular mole skinks: Area of habitat still above water given projected sea level rise and proportion of habitat at risk of storm surge in the Florida Keys, Cedar Keys, and Egmont Key, Florida
The primary habitats for insular mole skinks in Florida are sand beaches, beach berms, and dunes, making them particularly vulnerable to sea level rise (SLR) and storm surge. We used the most recent SLR projections, high resolution lidar-based digital elevation models, a combination of a comprehensive land cover and hand-digitized aerial imagery, and the latest storm surge simulations to...
Area of habitat still above water per decade of projected sea level rise for islands in two study areas off Florida's Gulf coast Area of habitat still above water per decade of projected sea level rise for islands in two study areas off Florida's Gulf coast
Sand beaches are dynamic, making it difficult to accurately predict habitat loss from sea level rise (SLR). We mapped sand beach habitat based on two datasets - a remotely sensed land cover and hand-digitized aerial imagery collected concurrently with digital elevation data. Data include the predicted area of beach habitat still above water (units = number of pixels) from SLR per decade...
Carbon and nitrogen isotopic values from three omnivorous turtles, vegetation, and potential prey resources in the Santa Fe River, Florida sampled 2019-2020 Carbon and nitrogen isotopic values from three omnivorous turtles, vegetation, and potential prey resources in the Santa Fe River, Florida sampled 2019-2020
All samples were collected within a 9km stretch of the Santa Fe River in northern Florida, USA. In 2019 and 2020 we sampled claw tissue from Macrochelys suwanniensis, Chelydra serpentina, and Trachemys scripta scripta, from three different sampling locations. We collected Vegetation and potential prey tissue samples within close proximity of turtle captures from two of the three capture...
Filter Total Items: 61
Persistence of a declining anuran species across its distribution Persistence of a declining anuran species across its distribution
Information on a species’ population dynamics, such as changes in abundance and distribution, can be used to identify declining populations and initiate conservation efforts and protections. For the Ornate Chorus Frog (Pseudacris ornata), anecdotal observations of local extirpation and population declines have been noted, but trends in its range-wide population status are generally...
Authors
Erin L. Koen, Edward Hance Ellington, William J. Barichivich, Howard Kochman, Kevin M. Enge, Susan E. Walls
Independent and interactive effects of disease and methylmercury on demographic rates across multiple amphibian populations Independent and interactive effects of disease and methylmercury on demographic rates across multiple amphibian populations
Disease, alone or combined with other stressors such as habitat loss and contaminants, affects wildlife populations worldwide. However, interactions among stressors and how they affect demography and populations remain poorly understood. The amphibian chytrid fungus (Batrachochytrium dendrobatidis; Bd) is a sometimes-lethal pathogen linked with population declines and extirpations of...
Authors
Morgan P. Kain, Blake R. Hossack, Kelly Smalling, Brian J. Halstead, Daniel A. Grear, David A. Miller, Michael J. Adams, Adam R. Backlin, William Barichivich, Collin A. Eagles-Smith, Colleen Emery, Jillian Elizabeth Fleming, Robert N. Fisher, Elizabeth Gallegos, Duoa J. Lor, Patrick M. Kleeman, Erin L. Muths, Ty Pan, Christopher Pearl, Charles W. Robinson, Caitlin Teresa Rumrill, Brian J. Tornabene, J. Hardin Waddle, Susan Walls, Evan H. Campbell Grant
Pan-amphibia distribution of the fungal parasite Batrachochytrium dendrobatidis varies with species and temperature Pan-amphibia distribution of the fungal parasite Batrachochytrium dendrobatidis varies with species and temperature
Batrachochytrium dendrobatidis (Bd) is a globally distributed fungal pathogen of amphibians that has contributed to one of the largest disease-related biodiversity losses in wildlife. Bd is regularly viewed through the lens of a global wildlife epizootic because the spread of highly virulent genetic lineages has resulted in well-documented declines and extinctions of multiple amphibian...
Authors
Daniel A. Grear, Michael J. Adams, Adam R. Backlin, William Barichivich, Adrianne Brand, Gary M. Bucciarelli, Daniel L. Calhoun, Tara Chestnut, Jon D Davenport, Andrew E Dietrich, Graziella V. DiRenzo, Robert N. Fisher, Brad Glorioso, Evan H. Campbell Grant, Brian J. Halstead, Marc P Hayes, Blake R. Hossack, Morgan Kain, Patrick M. Kleeman, Jeffrey M. Lorch, Brome McCreary, David A.W. Miller, Brittany A. Mosher, Erin L. Muths, Christopher Pearl, Charles H. Robinson, Mark Roth, Jennifer Rowe, Walter Sadinski, Brent H. Sigafus, Iga Stasiak, Samuel Sweet, Hardin Waddle, Susan Walls, Gregory J Watkins-Colwell, Lori A Williams, Megan Winzeler
Sea level rise threatens Florida’s insular vertebrate biodiversity Sea level rise threatens Florida’s insular vertebrate biodiversity
Islands are some of the most biodiverse places on earth, but they are also hotspots of biodiversity loss. The coastline of Florida, U.S.A., is surrounded by thousands of islands, many of which are home to species that occur nowhere else. A rapidly emerging threat to these low-lying islands is inundation as sea levels rise. The capacity of island-dwelling species to adapt to climate...
Authors
Erin L. Koen, William J. Barichivich, Elizabeth Braun De Torrez, Susan Walls
Amphibian and reptile conservation in the United States of America Amphibian and reptile conservation in the United States of America
Wildlife stewardship is of utmost importance in the United States, where management for sustainable natural resources is extended to native species including amphibians and reptiles. The U.S. wildlife conservation framework is a nested system of authorities regulating species and habitats, science-based management and policy decisions, and adaptive management as new knowledge is applied...
Authors
Deanna H. Olson, David S. Pilliod
Predicting the persistence of salamanders: consequences of phenological shifts for species of management concern on DoD lands Predicting the persistence of salamanders: consequences of phenological shifts for species of management concern on DoD lands
As climate change effects intensify, key life history events may become decoupled from necessary biotic and abiotic resources. For species of management concern on Department of Defense (DoD) lands, these shifts in phenology may prove difficult to address without a mechanistic understanding of the drivers of such changes. We sought to determine the causes and effects of phenological...
Authors
Susan Walls, Thomas L. Anderson, Houston C. Chandler, Carola A. Haas, Jon M. Davenport
Science and Products
Vulnerability of Mole Skinks to Sea-Level Rise
Mole skinks that occur on Florida’s islands rely on sand beaches, beach berms, and dunes, making them particularly vulnerable to sea level rise and storm surge. USGS researchers predicted the impacts of sea level rise and storm surge on habitat for the Florida Keys mole skink ( Plestiodon egregius egregius), the Cedar Key mole skink ( P. e. insularis), and the Egmont Key mole skink (known from a...
Predicting Sea-Level Rise Impacts to Barrier Island Habitats
Researchers at WARC are determining if temporal mismatches between digital elevation models and land cover data can impact estimates of inundation of beach habitat for barrier islands and low-lying beaches off the Gulf Coast of Florida.
Population Persistence of the Ornate Chorus Frog Across Its Distribution
The ornate chorus frog, once common throughout its range, appears to be experiencing population declines. USGS has partnered with the Florida Fish and Wildlife Conservation Commission to assess the ornate chorus frog population status across its distribution.
Sea-Level Rise and Florida’s Island Biodiversity
While islands are some of the most biodiverse places on earth, they are also among the most threatened. Researchers from WARC and Florida Fish and Wildlife Conservation Commission are assessing the vulnerability of Florida’s coastal islands to inundation from sea-level rise and estimating potential loss of the terrestrial biodiversity on Florida’s islands.
How Wildlife Respond to Tropical Cyclones: Short-Term Tactics and Long-Term Impacts
USGS is collaborating with the University of Florida to describe the diverse and fascinating tactics demonstrated by wildlife to survive tropical cyclones, which can aid in understanding the impact environmental change is having on wildlife and provide insights into how those impacts may be mitigated.
Informing Future Condition Scenario Planning for Habitat Specialists of the Imperiled Pine Rockland Ecosystem of South Florida
South Florida's pine rockland ecosystem represents less than 3% of its original extent. This project will evaluate habitat conditions for two pine rockland snake species to develop future habitat condition scenarios for Species Status Assessments.
Salamander species in headwater streams on state and federal public lands in the eastern United States Salamander species in headwater streams on state and federal public lands in the eastern United States
This dataset includes stream and species data collected in headwater streams on public lands throughout the eastern United States. Data were collected to inform updated species range maps and provide data for large-scale modeling of species ranges using multiple data types. All salamander species encountered are included in the dataset.
Range-wide probability of persistence of Ornate Chorus Frog populations and a habitat suitability map Range-wide probability of persistence of Ornate Chorus Frog populations and a habitat suitability map
Data include the probability of persistence of 407 Ornate Chorus Frog (Pseudacris ornata) populations across the distribution, as well as the mean habitat suitability, mean winter precipitation, and proportion of the surface that is impervious within each buffered population. Data also include the probability of persistence of Ornate Chorus Frog populations when different buffer sizes...
Sea level rise and Florida’s insular vertebrate biodiversity: predictions of island inundation and the number of coastal species vulnerable to sea level rise Sea level rise and Florida’s insular vertebrate biodiversity: predictions of island inundation and the number of coastal species vulnerable to sea level rise
Data include the proportion of Florida's coastal islands (n = 2504) that are projected to be inundated from sea level rise (SLR), as well as a prediction of the depth of SLR that would inundate each island. Data include the proportion of Florida's islands predicted to still be above water in 2100 that are currently human-modified. Data also include a count of the number of terrestrial...
Insular mole skinks: Area of habitat still above water given projected sea level rise and proportion of habitat at risk of storm surge in the Florida Keys, Cedar Keys, and Egmont Key, Florida Insular mole skinks: Area of habitat still above water given projected sea level rise and proportion of habitat at risk of storm surge in the Florida Keys, Cedar Keys, and Egmont Key, Florida
The primary habitats for insular mole skinks in Florida are sand beaches, beach berms, and dunes, making them particularly vulnerable to sea level rise (SLR) and storm surge. We used the most recent SLR projections, high resolution lidar-based digital elevation models, a combination of a comprehensive land cover and hand-digitized aerial imagery, and the latest storm surge simulations to...
Area of habitat still above water per decade of projected sea level rise for islands in two study areas off Florida's Gulf coast Area of habitat still above water per decade of projected sea level rise for islands in two study areas off Florida's Gulf coast
Sand beaches are dynamic, making it difficult to accurately predict habitat loss from sea level rise (SLR). We mapped sand beach habitat based on two datasets - a remotely sensed land cover and hand-digitized aerial imagery collected concurrently with digital elevation data. Data include the predicted area of beach habitat still above water (units = number of pixels) from SLR per decade...
Carbon and nitrogen isotopic values from three omnivorous turtles, vegetation, and potential prey resources in the Santa Fe River, Florida sampled 2019-2020 Carbon and nitrogen isotopic values from three omnivorous turtles, vegetation, and potential prey resources in the Santa Fe River, Florida sampled 2019-2020
All samples were collected within a 9km stretch of the Santa Fe River in northern Florida, USA. In 2019 and 2020 we sampled claw tissue from Macrochelys suwanniensis, Chelydra serpentina, and Trachemys scripta scripta, from three different sampling locations. We collected Vegetation and potential prey tissue samples within close proximity of turtle captures from two of the three capture...
Filter Total Items: 61
Persistence of a declining anuran species across its distribution Persistence of a declining anuran species across its distribution
Information on a species’ population dynamics, such as changes in abundance and distribution, can be used to identify declining populations and initiate conservation efforts and protections. For the Ornate Chorus Frog (Pseudacris ornata), anecdotal observations of local extirpation and population declines have been noted, but trends in its range-wide population status are generally...
Authors
Erin L. Koen, Edward Hance Ellington, William J. Barichivich, Howard Kochman, Kevin M. Enge, Susan E. Walls
Independent and interactive effects of disease and methylmercury on demographic rates across multiple amphibian populations Independent and interactive effects of disease and methylmercury on demographic rates across multiple amphibian populations
Disease, alone or combined with other stressors such as habitat loss and contaminants, affects wildlife populations worldwide. However, interactions among stressors and how they affect demography and populations remain poorly understood. The amphibian chytrid fungus (Batrachochytrium dendrobatidis; Bd) is a sometimes-lethal pathogen linked with population declines and extirpations of...
Authors
Morgan P. Kain, Blake R. Hossack, Kelly Smalling, Brian J. Halstead, Daniel A. Grear, David A. Miller, Michael J. Adams, Adam R. Backlin, William Barichivich, Collin A. Eagles-Smith, Colleen Emery, Jillian Elizabeth Fleming, Robert N. Fisher, Elizabeth Gallegos, Duoa J. Lor, Patrick M. Kleeman, Erin L. Muths, Ty Pan, Christopher Pearl, Charles W. Robinson, Caitlin Teresa Rumrill, Brian J. Tornabene, J. Hardin Waddle, Susan Walls, Evan H. Campbell Grant
Pan-amphibia distribution of the fungal parasite Batrachochytrium dendrobatidis varies with species and temperature Pan-amphibia distribution of the fungal parasite Batrachochytrium dendrobatidis varies with species and temperature
Batrachochytrium dendrobatidis (Bd) is a globally distributed fungal pathogen of amphibians that has contributed to one of the largest disease-related biodiversity losses in wildlife. Bd is regularly viewed through the lens of a global wildlife epizootic because the spread of highly virulent genetic lineages has resulted in well-documented declines and extinctions of multiple amphibian...
Authors
Daniel A. Grear, Michael J. Adams, Adam R. Backlin, William Barichivich, Adrianne Brand, Gary M. Bucciarelli, Daniel L. Calhoun, Tara Chestnut, Jon D Davenport, Andrew E Dietrich, Graziella V. DiRenzo, Robert N. Fisher, Brad Glorioso, Evan H. Campbell Grant, Brian J. Halstead, Marc P Hayes, Blake R. Hossack, Morgan Kain, Patrick M. Kleeman, Jeffrey M. Lorch, Brome McCreary, David A.W. Miller, Brittany A. Mosher, Erin L. Muths, Christopher Pearl, Charles H. Robinson, Mark Roth, Jennifer Rowe, Walter Sadinski, Brent H. Sigafus, Iga Stasiak, Samuel Sweet, Hardin Waddle, Susan Walls, Gregory J Watkins-Colwell, Lori A Williams, Megan Winzeler
Sea level rise threatens Florida’s insular vertebrate biodiversity Sea level rise threatens Florida’s insular vertebrate biodiversity
Islands are some of the most biodiverse places on earth, but they are also hotspots of biodiversity loss. The coastline of Florida, U.S.A., is surrounded by thousands of islands, many of which are home to species that occur nowhere else. A rapidly emerging threat to these low-lying islands is inundation as sea levels rise. The capacity of island-dwelling species to adapt to climate...
Authors
Erin L. Koen, William J. Barichivich, Elizabeth Braun De Torrez, Susan Walls
Amphibian and reptile conservation in the United States of America Amphibian and reptile conservation in the United States of America
Wildlife stewardship is of utmost importance in the United States, where management for sustainable natural resources is extended to native species including amphibians and reptiles. The U.S. wildlife conservation framework is a nested system of authorities regulating species and habitats, science-based management and policy decisions, and adaptive management as new knowledge is applied...
Authors
Deanna H. Olson, David S. Pilliod
Predicting the persistence of salamanders: consequences of phenological shifts for species of management concern on DoD lands Predicting the persistence of salamanders: consequences of phenological shifts for species of management concern on DoD lands
As climate change effects intensify, key life history events may become decoupled from necessary biotic and abiotic resources. For species of management concern on Department of Defense (DoD) lands, these shifts in phenology may prove difficult to address without a mechanistic understanding of the drivers of such changes. We sought to determine the causes and effects of phenological...
Authors
Susan Walls, Thomas L. Anderson, Houston C. Chandler, Carola A. Haas, Jon M. Davenport