Evan Grant, Ph.D.
Evan Grant the principle investigator of the US Geological Survey’s Amphibian Research and Monitoring Initiative (ARMI), northeast region, and stationed at the Patuxent Wildlife Research Center in Laurel, MD. Evan's research focuses on questions relating to amphibian populations, specifically with respect to their landscape-scale ecology and conservation. Evan's work is focused on monitoring and research questions which can aid resource managers and conservationists.
- 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
Research Gate profile: http://www.researchgate.net/profile/Evan_Grant2
Science and Products
The Challenge: Disease in amphibian populations can have a range of effects, from devastating declines following introduction of a novel pathogen to recurring breakout events on a landscape. Elucidating mechanisms underlying the effects of diseases on amphibian populations is crucial to help managers make appropriate decisions to achieve management goals for amphibians.
Currently, 90 amphibian species are recognized in the Northeast, including 59 species in the Order Caudata (salamanders) and 31 species in the Order Anura (frogs and toads). Almost half of the amphibians in the Northeast are salamanders within the family Plethodontidae. Amphibians are found in all physiographic regions of the Northeast, from sea level to the heights of the Appalachian, Adirondack, and White Mountains. The endangered Shenandoah salamander (Plethodon shenandoah) is a focal species in the central Appalachians.
The Challenge: In many National Parks organisms at high elevation are severely threatened and may be sensitive to changes in temperature and moisture gradients in the Appalachians, which may result in species extirpation in high elevation habitats. Many species are specifically adapted to the unusual conditions typical of high elevation sites; risks of extirpation increase as conditions change. Compounding the risk is the extraordinarily small range of many high elevation species; such is the case with the endangered Shenandoah salamander.
The North American Amphibian Monitoring Program (NAAMP) was a collaborative citizen science effort between the US Geological Survey (USGS) and 26 partners (state agencies, universities, and nonprofit organizations) for monitoring calling amphibian populations over much of the eastern and central United States. Initiated in 1997, in response to needs set forth by the Declining Amphibian Populations Task Force (DAPTF) in 1994, NAAMP was designed to provide scientifically and statistically defensible, long-term distribution and trend data for calling frog and toad populations at both the state and regional level.
The national program closed at the conclusion of the 2015 season.
Range position and climate sensitivity: the structure of among-population demographic responses to climatic variation
This data set is comprised of four files related to the counts of wood frog (Lithobates sylvaticus) egg masses in the Northeast United States and climatic information derived for the count locations. One file contains data for the counts at all locations, the other files contain derived temperature and precipitation data for models used in the published manuscript.
North American Amphibian Monitoring Program (NAAMP) anuran detection data from the eastern and central United States (1994-2015)
The North American Amphibian Monitoring Program (NAAMP) was a collaborative citizen science effort between the US Geological Survey (USGS) and 26 Partners (state agencies, universities, and nonprofits) for monitoring calling amphibian populations over much of the eastern and central United States.
Effects of host species and environment on the skin microbiome of Plethodontid salamanders
The amphibian skin microbiome is recognized for its role in defence against pathogens, including the deadly fungal pathogen Batrachochytrium dendrobatidis (Bd). Yet, we have little understanding of evolutionary and ecological processes that structure these communities, especially for salamanders and closely related species. We...Muletz-Wolz, Carly R.; Yarwood, Stephanie A.; Grant, Evan H. Campbell; Fleischer, Robert C.; Lips, Karen R.
Imperfect pathogen detection from non-invasive skin swabs biases disease inference
1. Conservation managers rely on accurate estimates of disease parameters, such as pathogen prevalence and infection intensity, to assess disease status of a host population. However, these disease metrics may be biased if low-level infection intensities are missed by sampling methods or laboratory diagnostic tests. These false negatives...DiRenzo, Graziella V.; Grant, Evan H. Campbell; Longo, Ana; Che-Castaldo, Christian; Zamudio, Kelly R.; Lips, Karen
Range position and climate sensitivity: The structure of among-population demographic responses to climatic variation
Species’ distributions will respond to climate change based on the relationship between local demographic processes and climate and how this relationship varies based on range position. A rarely tested demographic prediction is that populations at the extremes of a species’ climate envelope (e.g., populations in areas with the highest mean annual...Amburgey, Staci M.; Miller, David A. W.; Grant, Evan H. Campbell; Rittenhouse, Tracy A. G.; Benard, Michael F.; Richardson, Jonathan L.; Urban, Mark C.; Hughson, Ward; Brand, Adrianne B,; Davis, Christopher J.; Hardin, Carmen R.; Paton, Peter W. C.; Raithel, Christopher J.; Relyea, Rick A.; Scott, A. Floyd; Skelly, David K.; Skidds, Dennis E.; Smith, Charles K.; Werner, Earl E.
Heterogeneous responses of temperate-zone amphibian populations to climate change complicates conservation planning
The pervasive and unabated nature of global amphibian declines suggests common demographic responses to a given driver, and quantification of major drivers and responses could inform broad-scale conservation actions. We explored the influence of climate on demographic parameters (i.e., changes in the probabilities of survival and recruitment)...Muths, Erin L.; Chambert, Thierry A.; Schmidt, B. R.; Miller, D. A. W.; Hossack, Blake R.; Joly, P.; Grolet, O.; Green, D. M.; Pilliod, David; Cheylan, M.; Fisher, Robert N.; McCaffery, R. M.; Adams, M. J.; Palen, W. J.; Arntzen, J. W.; Garwood, J.; Fellers, Gary M.; Thirion, J. M.; Grant, Evan H. Campbell; Besnard, A.
Design tradeoffs in long-term research for stream salamanders
Long-term research programs can benefit from early and periodic evaluation of their ability to meet stated objectives. In particular, consideration of the spatial allocation of effort is key. We sampled 4 species of stream salamanders intensively for 2 years (2010–2011) in the Chesapeake and Ohio Canal National Historical Park, Maryland, USA to...Brand, Adrianne B,; Grant, Evan H. Campbell
Evolutionary dynamics of an expressed MHC class IIβ locus in the Ranidae (Anura) uncovered by genome walking and high-throughput amplicon sequencing
The Major Histocompatibility Complex (MHC) is a genomic region encoding immune loci that are important and frequently used markers in studies of adaptive genetic variation and disease resistance. Given the primary role of infectious diseases in contributing to global amphibian declines, we characterized the hypervariable exon 2 and flanking...Mulder, Kevin P.; Cortazar-Chinarro, Maria; Harris, D. James; Crottini, Angelica; Grant, Evan H. Campbell; Fleischer, Robert C.; Savage, Anna E.
Integrating count and detection–nondetection data to model population dynamics
There is increasing need for methods that integrate multiple data types into a single analytical framework as the spatial and temporal scale of ecological research expands. Current work on this topic primarily focuses on combining capture–recapture data from marked individuals with other data types into integrated population models. Yet, studies...Zipkin, Elise F.; Rossman, Sam; Yackulic, Charles B.; Wiens, David; Thorson, James T.; Davis, Raymond J.; Grant, Evan H. Campbell
Antifungal bacteria on woodland salamander skin exhibit high taxonomic diversity and geographic variability
Diverse bacteria inhabit amphibian skin; some of those bacteria inhibit growth of the fungal pathogen Batrachochytrium dendrobatidis. Yet there has been no systematic survey of anti-B. dendrobatidis bacteria across localities, species, and elevations. This is important given geographic and taxonomic variations in amphibian susceptibility to B....Muletz-Wolz, Carly R.; DiRenzo, Graziella V.; Yarwood, Stephanie A.; Grant, Evan H. Campbell; Fleischer, Robert C.; Lips, Karen R.
Using decision analysis to support proactive management of emerging infectious wildlife diseases
Despite calls for improved responses to emerging infectious diseases in wildlife, management is seldom considered until a disease has been detected in affected populations. Reactive approaches may limit the potential for control and increase total response costs. An alternative, proactive management framework can identify immediate actions that...Grant, Evan H. Campbell; Muths, Erin L.; Katz, Rachel A.; Canessa, Stefano; Adams, Michael J.; Ballard, Jennifer R.; Berger, Lee; Briggs, Cheryl J.; Coleman, Jeremy; Gray, Matthew J.; Harris, M. Camille; Harris, Reid N.; Hossack, Blake R.; Huyvaert, Kathryn P.; Kolby, Jonathan E.; Lips, Karen R.; Lovich, Robert E.; McCallum, Hamish I.; Mendelson, Joseph R.; Nanjappa, Priya; Olson, Deanna H.; Powers, Jenny G.; Richgels, Katherine L. D.; Russell, Robin E.; Schmidt, Benedikt R.; Spitzen-van der Sluijs, Annemarieke; Watry, Mary Kay; Woodhams, Douglas C.; White, C. LeAnn
Detecting spatial ontogenetic niche shifts in complex dendritic ecological networks
Ontogenetic niche shifts (ONS) are important drivers of population and community dynamics, but they can be difficult to identify for species with prolonged larval or juvenile stages, or for species that inhabit continuous habitats. Most studies of ONS focus on single transitions among discrete habitat patches at local scales. However, for species...Fields, William R.; Grant, Evan H. Campbell; Lowe, Winsor H.
Nocturnal insect availability in bottomland hardwood forests managed for wildlife in the Mississippi Alluvial Valley
Silviculture used to alter forest structure and thereby enhance wildlife habitat has been advocated for bottomland hardwood forest management on public conservation lands in the Mississippi Alluvial Valley. Although some songbirds respond positively to these management actions to attain desired forest conditions for wildlife, the response of other...Loraine Ketzler; Christopher Comer; Twedt, Daniel J.
Climate-mediated competition in a high-elevation salamander community
The distribution of the federally endangered Shenandoah Salamander (Plethodon shenandoah) is presumed to be limited by competition with the Red-backed Salamander (Plethodon cinereus). In particular, the current distribution of P. shenandoah is understood to be restricted to warmer and drier habitats because of interspecific interactions. These...Dallalio, Eric A.; Brand, Adrianne B,; Grant, Evan H. Campbell
New U.S. Geological Survey-led research suggests that even though amphibians are severely declining worldwide, there is no smoking gun – and thus no simple solution – to halting or reversing these declines.