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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: 1211

Time to get real with qPCR controls: The frequency of sample contamination and the informative power of negative controls in environmental DNA studies

Environmental (e)DNA methods have enabled rapid, sensitive and specific inferences of taxa presence throughout diverse fields of ecological study. However, use of eDNA results for decision-making has been impeded by uncertainties associated with false positive tests putatively caused by sporadic or systemic contamination. Sporadic contamination is a process that is inconsistent across samples and
Authors
Patrick Ross Hutchins, Leah Nicole Simantel, Adam Sepulveda

Distribution of tiger salamanders in northern Sonora, Mexico: Comparison of sampling methods and possible implications for an endangered subspecies

Many aquatic species in the arid USA-Mexico borderlands region are imperiled, but limited information on distributions and threats often hinders management. To provide information on the distribution of the Western Tiger Salamander (Ambystoma mavortium), including the USA-federally endangered Sonoran Tiger Salamander (Ambystoma mavortium stebbinsi), we used traditional (seines, dip-nets) and moder
Authors
Blake R. Hossack, Julio A. Lemos-Espinal, Brent H. Sigafus, Erin L. Muths, Gerardo Carreon Arroyo, Daniel Toyos Martinez, David Hurtado Felix, Guillermo Molina Padilla, Caren S. Goldberg, T. R. Jones, M. J. Sredl, Thierry Chambert, J. C. Rorabaugh

Species invasion progressively disrupts the trophic structure of native food webs

Species invasions can have substantial impacts on native species and ecosystems, with important consequences for biodiversity. How these disturbances drive changes in the trophic structure of native food webs through time is poorly understood. Here, we quantify trophic disruption in freshwater food webs to invasion by an apex fish predator, lake trout, using an extensive stable isotope dataset acr
Authors
Charles Wainright, Clint C. Muhlfeld, James J. Elser, Samuel Bourret, Shawn P. Devlin

Genetic attributes and research interests

No abstract available.
Authors
Elizabeth P Flesch, Tabitha Graves, Robert A. Garrott, Sarah Dewey, Carson Butler

Sustaining transmission in different host species: The emblematic case of Sarcoptes scabiei

Some pathogens sustain transmission in multiple different host species, but how this epidemiologically important feat is achieved remains enigmatic. Sarcoptes scabiei is among the most host generalist and successful of mammalian parasites. We synthesize pathogen and host traits that mediate sustained transmission and present cases illustrating three transmission mechanisms (direct, indirect, and c
Authors
E Browne, MM Driessen, Paul C. Cross, L. E. Escobar, Janet E. Foley, JR López-Olvera, KD Niedringhaus, Liza Rossi, Scott Carver

Testing a generalizable machine learning workflow for aquatic invasive species on Rainbow Trout (Oncorhynchus mykiss) in northwest Montana

Biological invasions are accelerating worldwide, causing major ecological and economic impacts in aquatic ecosystems. The urgent decision-making needs of invasive species managers can be better met by the integration of biodiversity big data with large-domain models and data-driven products. Remotely sensed data products can be combined with existing invasive species occurrence data via machine le
Authors
Sean C. Carter, Charles B. van Rees, Brian K. Hand, Clint C. Muhlfeld, Gordon Luikart, John S Kimball

Scavengers reduce potential brucellosis transmission risk in the Greater Yellowstone Ecosystem

Scavengers likely play an important role in ecosystem energy flow as well as disease transmission, but whether they facilitate or reduce disease transmission is often unknown. In the Greater Yellowstone Ecosystem, scavengers are likely to reduce the transmission and subsequent spread of brucellosis within and between livestock and elk by consuming infectious abortion materials, thereby removing th
Authors
Kimberly E Szcodronski, Paul C. Cross

Applying assessments of adaptive capacity to inform natural-resource management in a changing climate

Adaptive capacity (AC)—the ability of a species to cope with or accommodate climate change—is a critical determinant of species vulnerability. Using information on species’ AC in conservation planning is key to ensuring successful outcomes. We identified connections between a list of species’ attributes (e.g., traits, population metrics, and behaviors) that were recently proposed for assessing spe
Authors
Lindsey Thurman, John E. Gross, Claudia Mengelt, Erik A. Beever, Laura Thompson, Gregor W. Schuurman, Christopher Hoving, Julian D. Olden

Staggered-entry analysis of breeding phenology and occupancy dynamics of Arizona toads from historically occupied habitats of New Mexico, USA

For species with variable phenology, it is often challenging to produce reliable estimates of population dynamics or changes in occupancy. The Arizona Toad (Anaxyrus microscaphus) is a southwestern USA endemic that has been petitioned for legal protection, but status assessments are limited by a lack of information on population trends. Also, timing and consistency of Arizona Toad breeding varies
Authors
MJ Forzley, Mason J. Ryan, IM Latella, JT Giermakowski, Erin L. Muths, Brent H. Sigafus, Blake R. Hossack

Natural history of a bighorn sheep pneumonia epizootic: Source of infection, course of disease, and pathogen clearance

A respiratory disease epizootic at the National Bison Range (NBR) in Montana in 2016–2017 caused an 85% decline in the bighorn sheep population, documented by observations of its unmarked but individually identifiable members, the subjects of an ongoing long-term study. The index case was likely one of a small group of young bighorn sheep on a short-term exploratory foray in early summer of 2016.
Authors
T. E. Besser, E. Frances Cassirer, Amy Lisk, Danielle Nelson, Kezia R. Manlove, Paul C. Cross, John T. Hogg

Fish response to successive clearcuts in a second-growth forest from the central Coast range of Oregon

Research dating back to the 1950 s has documented negative effects from harvesting of primeval forests on stream ecosystems of the Pacific Northwest. By the early 1990 s, state and federal forest practice rules governing timber harvest were modified throughout North America to better protect aquatic habitats and biotic resources, principally salmonids. These rules inspired a generation of studies
Authors
D. S. Bateman, Nathan Chelgren, Robert E. Gresswell, Jason B. Dunham, David Hockman-Wert, D. W. Leer, K. D. Bladon

What do you mean by false positive?

Misunderstandings regarding the term “false positive” present a significant hurdle to broad adoption of eDNA monitoring methods. Here, we identify three challenges to clear communication of false-positive error between scientists, managers, and the public. The first arises from a failure to distinguish between false-positive eDNA detection at the sample level and false-positive inference of taxa p
Authors
John A. Darling, Christopher L. Jerde, Adam Sepulveda