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Publications

Below is a list of available NOROCK peer reviewed and published science. If you are in search of a specific publication and cannot find it below or through a search, please contact twojtowicz@usgs.gov.

Filter Total Items: 1197

Tooth wear and the apparent consumption of human foods among American black bears (Ursus americanus) in Great Smoky Mountains National Park, USA

Stable isotope analyses of hair have been used to estimate the consumption of human foods by American black bears (Ursus americanus). Consumption of human foods influences body mass and reproductive success of bears. However, the underlying factors that cause some bears to become conflict bears and resort to consuming human foods as a portion of their diet are not fully understood. We collected ha
Authors
Kent A. Hatch, Kimberly A. Kester, Amanda Loveless, Beverly L. Roeder, Frank T. van Manen

Assessing the seasonal evolution of snow depth spatial variability and scaling in complex mountain terrain

Dynamic natural processes govern snow distribution in mountainous environments throughout the world. Interactions between these different processes create spatially variable patterns of snow depth across a landscape. Variations in accumulation and redistribution occur at a variety of spatial scales, which are well established for moderate mountain terrain. However, spatial patterns of snow depth v
Authors
Zachary Miller, Erich Peitzsch, Eric A. Sproles, Karl W. Birkeland, Ross T. Palomaki

Empirical evidence for effects of invasive American Bullfrogs on occurrence of native amphibians and emerging pathogens

Invasive species and emerging infectious diseases are two of the greatest threats to biodiversity. American Bullfrogs (Rana [Lithobates] catesbeiana), which have been introduced to many parts of the world, are often linked with declines of native amphibians via predation and spreading emerging pathogens such as amphibian chytrid fungus (Batrachochytrium dendrobatidis [Bd]) and ranaviruses. Althoug
Authors
Blake R. Hossack, Emily B Oja, Audrey K Owens, David L. Hall, Cassidi Cobos, Catherine L. Crawford, Caren S. Goldberg, Shaula Hedwell, Paige E. Howell, Julio A. Lemos-Espinal, Susan K MacVean, Magnus McCaffery, Cody Mosley, Erin L. Muths, Brent H. Sigafus, Micahel J Sredl, James C. Rorabaugh

Historical Structure from Motion (HSfM): Automated processing of historical aerial photographs for long-term topographic change analysis

Precisely measuring the Earth’s changing surface on decadal to centennial time scales is critical for many science and engineering applications, yet long-term records of quantitative landscape change are often temporally and geographically sparse. Archives of scanned historical aerial photographs provide an opportunity to augment these records with accurate elevation measurements that capture the
Authors
Friedrich Knuth, David Shean, Shashank Bhushan, Eli Schwat, Oleg Alexandrov, Christopher J. McNeil, Amaury Dehecq, Caitlyn Florentine, Shad O'Neel

Understanding local adaptation to prepare populations for climate change

Adaptation within species to local environments is widespread in nature. Better understanding this local adaptation is critical to conserving biodiversity. However, conservation practices can rely on species’ trait averages or can broadly assume homogeneity across the range to inform management. Recent methodological advances for studying local adaptation provide the opportunity to fine-tune effor
Authors
Mariah H. Meek, Erik A. Beever, Soraia Barbosa, Sarah W. Fitzpatrick, Nicholas K. Fletcher, Cinnamon S. Mittan-Moreau, Brendan N. Reid, Shane C. Campbell-Staton, Nancy Green, Jessica J. Hellmann

Evaluating noninvasive methods for estimating cestode prevalence in a wild carnivore population

Helminth infections are cryptic and can be difficult to study in wildlife species. Helminth research in wildlife hosts has historically required invasive animal handling and necropsy, while results from noninvasive parasite research, like scat analysis, may not be possible at the helminth species or individual host levels. To increase the utility of noninvasive sampling, individual hosts can be id
Authors
E E Brandell, M.K. Jackson, Paul C. Cross, A.J. Piaggio, D. R. Taylor, Douglas W. Smith, B Boufana, Daniel R. Stahler, PJ Hudson

High dispersal rates in hybrids drive expansion of maladaptive hybridization

Hybridization between native and invasive species, a major cause of biodiversity loss, can spread rapidly even when hybrids have reduced fitness. This paradox suggests that hybrids have greater dispersal rates than non-hybridized individuals, yet this mechanism has not been empirically tested in animal populations. Here, we test if non-native genetic introgression increases reproductive dispersal
Authors
Samuel Bourret, Ryan P. Kovach, Timothy Joseph Cline, Jeffrey Strait, Clint C. Muhlfeld

Linking evolutionary potential to extinction risk: Applications and future directions

Extinction-risk assessments play a major role in prioritizing conservation action at national and international levels. However, quantifying extinction risk is challenging, especially when including the full suite of adaptive responses to environmental change. In particular, evolutionary potential (EP), the capacity to evolve genetically based changes that increase fitness under changing condition
Authors
Brenna R. Forester, Erik A. Beever, Catherine Darst, Jennifer Szymanski, W. Chris Funk

Gaining decision-maker confidence through community consensus: Developing environmental DNA standards for data display on the USGS Nonindigenous Aquatic Species database

To advance national efforts for the detection and biosurveillance of aquatic invasive species (AIS), we employed a community consensus process to enable the incorporation of environmental DNA (eDNA) detection data into the U.S. Geological Survey’s (USGS) Nonindigenous Aquatic Species (NAS) database (https://nas.er.usgs.gov/eDNA/). Our goal was to identify minimum standards and best practices for t
Authors
Jason Ferrante, Wesley Daniel, Jonathan (Contractor) Adam Freedman, Katy E. Klymus, Matthew Neilson, Yale Passamaneck, Christopher B. Rees, Adam J. Sepulveda, Margaret Hunter

Uncertainty of ICESat-2 ATL06- and ATL08-derived snow depths for glacierized and vegetated mountain regions

Seasonal snow melt dominates the hydrologic budget across a large portion of the globe. Snow accumulation and melt vary over a broad range of spatial scales, preventing accurate extrapolation of sparse in situ observations to watershed scales. The lidar onboard the Ice, Cloud, and land Elevation, Satellite (ICESat-2) was designed for precise mapping of ice sheets and sea ice, and here we assess th
Authors
Ellyn Enderlin, Colten Elkin, Madeline Gendreau, H. P. Marshall, Shad O'Neel, Christopher J. McNeil, Caitlyn Florentine, Louis C. Sass

Disease outbreaks select for mate choice and coat color in wolves

We know much about pathogen evolution and the emergence of new disease strains, but less about host resistance and how it is signaled to other individuals and subsequently maintained. The cline in frequency of black-coated wolves (Canis lupus) across North America is hypothesized to result from a relationship with canine distemper virus (CDV) outbreaks. We tested this hypothesis using cross-sectio
Authors
Sarah Cubaynes, E E Brandell, Daniel R. Stahler, Douglas W. Smith, Emily S. Almberg, Susanne Schindler, Robert K. Wayne, Andrew P. Dobson, Bridgett M. vonHoldt, Daniel R. MacNulty, Paul C. Cross, Peter J. Hudson, Tim Coulson

Antecedent climatic conditions spanning several years influence multiple land-surface phenology events in semi-arid environments

Ecological processes are complex, often exhibiting non-linear, interactive, or hierarchical relationships. Furthermore, models identifying drivers of phenology are constrained by uncertainty regarding predictors, interactions across scales, and legacy impacts of prior climate conditions. Nonetheless, measuring and modeling ecosystem processes such as phenology remains critical for management of ec
Authors
David J. A. Wood, Paul C. Stoy, Scott Powell, Erik A. Beever