Evan Grant, Ph.D.
Evan Grant the principle investigator of the US Geological Survey’s Amphibian Research and Monitoring Initiative (ARMI), northeast region.
Evan's research focuses on questions relating to amphibian populations, specifically with respect to their landscape-scale ecology. Evan also uses decision science to aid resource managers.
Education:
- PhD, 2009, University of Maryland College Park, Program of Marine, Estuarine and Environmental Sciences and Department of Entomology
- BS, 2001, Cornell University, Natural Resources, with Distinction in Research
ResearcherID: N-5160-2014
Research Gate profile: http://www.researchgate.net/profile/Evan_Grant2
Science and Products
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Potential reduction in terrestrial salamander ranges associated with Marcellus shale development
Natural gas production from the Marcellus shale is rapidly increasing in the northeastern United States. Most of the endemic terrestrial salamander species in the region are classified as ‘globally secure’ by the IUCN, primarily because much of their ranges include state- and federally protected lands, which have been presumed to be free from habitat loss. However, the proposed and ongoing develop
Authors
Adrianne B. Brand, Amber N. M. Wiewel, Evan H. Campbell Grant
Please don't misuse the museum: 'declines' may be statistical
Detecting declines in populations at broad spatial scales takes enormous effort, and long-term data are often more sparse than is desired for estimating trends, identifying drivers for population changes, framing conservation decisions or taking management actions. Museum records and historic data can be available at large scales across multiple decades, and are therefore an attractive source of i
Authors
Evan H. Campbell Grant
Inferences about population dynamics from count data using multi-state models: A comparison to capture-recapture approaches
Wildlife populations consist of individuals that contribute disproportionately to growth and viability. Understanding a population's spatial and temporal dynamics requires estimates of abundance and demographic rates that account for this heterogeneity. Estimating these quantities can be difficult, requiring years of intensive data collection. Often, this is accomplished through the capture and re
Authors
Evan H. Campbell Grant, Elise Zipkin, Sillett T. Scott, Richard Chandler, J. Andrew Royle
Stream water temperature limits occupancy of salamanders in mid-Atlantic protected areas
Stream ecosystems are particularly sensitive to urbanization, and tolerance of water-quality parameters is likely important to population persistence of stream salamanders. Forecasted climate and landscape changes may lead to significant changes in stream flow, chemical composition, and temperatures in coming decades. Protected areas where landscape alterations are minimized will therefore become
Authors
Evan H. Campbell Grant, Amber N. M. Wiewel, Karen C. Rice
Modeling structured population dynamics using data from unmarked individuals
The study of population dynamics requires unbiased, precise estimates of abundance and vital rates that account for the demographic structure inherent in all wildlife and plant populations. Traditionally, these estimates have only been available through approaches that rely on intensive mark–recapture data. We extended recently developed N-mixture models to demonstrate how demographic parameters a
Authors
Evan H. Campbell Grant, Elise Zipkin, James T. Thorson, Kevin See, Heather J. Lynch, Yoichiro Kanno, Richard Chandler, Benjamin H. Letcher, J. Andrew Royle
Management and monitoring of the endangered Shenandoah salamander under climate change: Workshop report 10-12 April 2012
Here we report on a structured decision making (SDM) process to identify management strategies to ensure persistence of the federally endangered Shenandoah salamander (Plethodon shenandoah), given that it may be at increased extinction risk under projected climate change. The focus of this report is the second of two SDM workshops; in the first workshop, participants developed a prototype of the d
Authors
Evan H. Campbell Grant, John E. B. Wofford, D. R. Smith, J. Dennis, C. Hawkins-Hoffman, J. Schaberl, M. Foley, M. Bogle
Relaxing the closure assumption in single-season occupancy models: staggered arrival and departure times
Occupancy statistical models that account for imperfect detection have proved very useful in several areas of ecology, including species distribution and spatial dynamics, disease ecology, and ecological responses to climate change. These models are based on the collection of multiple samples at each of a number of sites within a given season, during which it is assumed the species is either absen
Authors
William L. Kendall, James E. Hines, James D. Nichols, Evan H. Campbell Grant
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
Presence-only modeling using MAXENT: when can we trust the inferences?
1. Recently, interest in species distribution modelling has increased following the development of new methods for the analysis of presence-only data and the deployment of these methods in user-friendly and powerful computer programs. However, reliable inference from these powerful tools requires that several assumptions be met, including the assumptions that observed presences are the consequence
Authors
Charles B. Yackulic, Richard Chandler, Elise F. Zipkin, J. Andrew Royle, James D. Nichols, Evan H. Campbell Grant, Sophie Veran
The state of amphibians in the United States
More than 25 years ago, scientists began to identify unexplained declines in amphibian populations around the world. Much has been learned since then, but amphibian declines have not abated and the interactions among the various threats to amphibians are not clear. Amphibian decline is a problem of local, national, and international scope that can affect ecosystem function, biodiversity, and comme
Authors
E. Muths, M.J. Adams, E.H.C. Grant, D. Miller, P. S. Corn, L.C. Ball
Evaluating the predictive abilities of community occupancy models using AUC while accounting for imperfect detection
The ability to accurately predict patterns of species' occurrences is fundamental to the successful management of animal communities. To determine optimal management strategies, it is essential to understand species-habitat relationships and how species habitat use is related to natural or human-induced environmental changes. Using five years of monitoring data in the Chesapeake and Ohio Canal N
Authors
Elise F. Zipkin, Evan H. Campbell Grant, William F. Fagan
Experimental investigation of false positive errors in auditory species occurrence surveys
False positive errors are a significant component of many ecological data sets, which in combination with false negative errors, can lead to severe biases in conclusions about ecological systems. We present results of a field experiment where observers recorded observations for known combinations of electronically broadcast calling anurans under conditions mimicking field surveys to determine spec
Authors
David A.W. Miller, Linda A. Weir, Brett T. McClintock, Evan H. Campbell Grant, Larissa L. Bailey, Theodore R. Simons
Science and Products
Filter Total Items: 20
Filter Total Items: 15
No Result Found
Filter Total Items: 130
Potential reduction in terrestrial salamander ranges associated with Marcellus shale development
Natural gas production from the Marcellus shale is rapidly increasing in the northeastern United States. Most of the endemic terrestrial salamander species in the region are classified as ‘globally secure’ by the IUCN, primarily because much of their ranges include state- and federally protected lands, which have been presumed to be free from habitat loss. However, the proposed and ongoing develop
Authors
Adrianne B. Brand, Amber N. M. Wiewel, Evan H. Campbell Grant
Please don't misuse the museum: 'declines' may be statistical
Detecting declines in populations at broad spatial scales takes enormous effort, and long-term data are often more sparse than is desired for estimating trends, identifying drivers for population changes, framing conservation decisions or taking management actions. Museum records and historic data can be available at large scales across multiple decades, and are therefore an attractive source of i
Authors
Evan H. Campbell Grant
Inferences about population dynamics from count data using multi-state models: A comparison to capture-recapture approaches
Wildlife populations consist of individuals that contribute disproportionately to growth and viability. Understanding a population's spatial and temporal dynamics requires estimates of abundance and demographic rates that account for this heterogeneity. Estimating these quantities can be difficult, requiring years of intensive data collection. Often, this is accomplished through the capture and re
Authors
Evan H. Campbell Grant, Elise Zipkin, Sillett T. Scott, Richard Chandler, J. Andrew Royle
Stream water temperature limits occupancy of salamanders in mid-Atlantic protected areas
Stream ecosystems are particularly sensitive to urbanization, and tolerance of water-quality parameters is likely important to population persistence of stream salamanders. Forecasted climate and landscape changes may lead to significant changes in stream flow, chemical composition, and temperatures in coming decades. Protected areas where landscape alterations are minimized will therefore become
Authors
Evan H. Campbell Grant, Amber N. M. Wiewel, Karen C. Rice
Modeling structured population dynamics using data from unmarked individuals
The study of population dynamics requires unbiased, precise estimates of abundance and vital rates that account for the demographic structure inherent in all wildlife and plant populations. Traditionally, these estimates have only been available through approaches that rely on intensive mark–recapture data. We extended recently developed N-mixture models to demonstrate how demographic parameters a
Authors
Evan H. Campbell Grant, Elise Zipkin, James T. Thorson, Kevin See, Heather J. Lynch, Yoichiro Kanno, Richard Chandler, Benjamin H. Letcher, J. Andrew Royle
Management and monitoring of the endangered Shenandoah salamander under climate change: Workshop report 10-12 April 2012
Here we report on a structured decision making (SDM) process to identify management strategies to ensure persistence of the federally endangered Shenandoah salamander (Plethodon shenandoah), given that it may be at increased extinction risk under projected climate change. The focus of this report is the second of two SDM workshops; in the first workshop, participants developed a prototype of the d
Authors
Evan H. Campbell Grant, John E. B. Wofford, D. R. Smith, J. Dennis, C. Hawkins-Hoffman, J. Schaberl, M. Foley, M. Bogle
Relaxing the closure assumption in single-season occupancy models: staggered arrival and departure times
Occupancy statistical models that account for imperfect detection have proved very useful in several areas of ecology, including species distribution and spatial dynamics, disease ecology, and ecological responses to climate change. These models are based on the collection of multiple samples at each of a number of sites within a given season, during which it is assumed the species is either absen
Authors
William L. Kendall, James E. Hines, James D. Nichols, Evan H. Campbell Grant
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
Presence-only modeling using MAXENT: when can we trust the inferences?
1. Recently, interest in species distribution modelling has increased following the development of new methods for the analysis of presence-only data and the deployment of these methods in user-friendly and powerful computer programs. However, reliable inference from these powerful tools requires that several assumptions be met, including the assumptions that observed presences are the consequence
Authors
Charles B. Yackulic, Richard Chandler, Elise F. Zipkin, J. Andrew Royle, James D. Nichols, Evan H. Campbell Grant, Sophie Veran
The state of amphibians in the United States
More than 25 years ago, scientists began to identify unexplained declines in amphibian populations around the world. Much has been learned since then, but amphibian declines have not abated and the interactions among the various threats to amphibians are not clear. Amphibian decline is a problem of local, national, and international scope that can affect ecosystem function, biodiversity, and comme
Authors
E. Muths, M.J. Adams, E.H.C. Grant, D. Miller, P. S. Corn, L.C. Ball
Evaluating the predictive abilities of community occupancy models using AUC while accounting for imperfect detection
The ability to accurately predict patterns of species' occurrences is fundamental to the successful management of animal communities. To determine optimal management strategies, it is essential to understand species-habitat relationships and how species habitat use is related to natural or human-induced environmental changes. Using five years of monitoring data in the Chesapeake and Ohio Canal N
Authors
Elise F. Zipkin, Evan H. Campbell Grant, William F. Fagan
Experimental investigation of false positive errors in auditory species occurrence surveys
False positive errors are a significant component of many ecological data sets, which in combination with false negative errors, can lead to severe biases in conclusions about ecological systems. We present results of a field experiment where observers recorded observations for known combinations of electronically broadcast calling anurans under conditions mimicking field surveys to determine spec
Authors
David A.W. Miller, Linda A. Weir, Brett T. McClintock, Evan H. Campbell Grant, Larissa L. Bailey, Theodore R. Simons