Northern Rocky Mountain Science Center (NOROCK)
Impacts of nonnative Brown Trout on Yellowstone Cutthroat Trout in a tributary stream
Nonnative trout are a considerable threat to native salmonids, yet our understanding of the mechanisms behind interspecific interactions remains limited. We evaluated the impacts of nonnative Brown Trout Salmo salar on a population of Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri in Montana. We contrasted diets,...Al-Chokhachy, Robert K.; Sepulveda, Adam J.
Extreme value-based methods for modeling elk movements
Species range shifts and the spread of diseases are both likely to be driven by extreme movements, but are difficult to statistically model due to their rarity. We propose a statistical approach for characterizing movement kernels that incorporate landscape covariates as well as the potential for heavy-tailed distributions. We used a spliced...Wijeyakulasuriya, Dhanushi A.; Hanks, Ephraim M.; Shaby, Benjamin A.; Cross, Paul C.
Change in dominance determines herbivore effects on plant biodiversity
Herbivores alter plant biodiversity (species richness) in many of the world’s ecosystems, but the magnitude and the direction of herbivore effects on biodiversity vary widely within and among ecosystems. One current theory predicts that herbivores enhance plant biodiversity at high productivity but have the opposite effect at low productivity. Yet...Koerner, Sally E.; Smith, Melinda D.; Burkepile, Deron E.; Hanan, Niall P.; Avolio, Meghan L.; Collins, Scott L.; Knapp, Alan K.; Lemoine, Nathan P.; Forrestel, Elisabeth J.; Eby, Stephanie; Thompson, Dave I.; Aguado-Santacruz, Gerardo A.; Anderson, John P.; Anderson, T. Michael; Angassa, Ayana; Bagchi, Sumanta; Bakker, Elisabeth S.; Bastin, Gary; Baur, Lauren E.; Beard, Karen H.; Beever, Erik; Bohlen, Patrick J.; Boughton, Elizabeth H.; Canestro, Don; Cesa, Ariela; Chaneton, Enrique; Cheng, Jimin; D'Antonio, Carla M.; Deleglise, Claire; Dembélé, Fadiala; Dorrough, Josh; Eldridge, David J.; Fernandez-Going, Barbara; Fernández-Lugo, Silvia; Fraser, Lauchlan H.; Freedman, Bill; García-Salgado, Gonzalo; Goheen, Jacob R.; Guo, Liang; Husheer, Sean; Karembé, Moussa; Knops, Johannes M. H.; Kraaij, Tineke; Kulmatiski, Andrew; Kytöviita, Minna-Maarit; Lezama, Felipe; Loucougaray, Gregory; Loydi, Alejandro; Milchunas, Daniel G.; Milton, Suzanne J.; Morgan, John W.; Moxham, Claire; Nehring, Kyle C.; Olff, Han; Palmer, Todd M.; Rebollo, Salvador; Riginos, Corinna; Risch, Anita C.; Rueda, Marta; Sankaran, Mahesh; Sasaki, Takehiro; Schoenecker, Kathryn A.; Schultz, Nick L.; Schütz, Martin; Schwabe, Angelika; Siebert, Frances; Smit, Christian; Stahlheber, Karen A.; Storm, Christian; Strong, Dustin J.; Su, Jishuai; Tiruvaimozhi, Yadugiri V.; Tyler, Claudia; Val, James; Vandegehuchte, Martijn L.; Veblen, Kari E.; Vermeire, Lance; Ward, David; Wu, Jianshuang; Young, Truman P.; Yu, Qiang; Zelikova, Tamara J.
Estimating the risk of elk-to-livestock brucellosis transmission in Montana
Wildlife reservoirs of infectious disease are a major source of human-wildlife conflict because of the risk of potential spillover associated with commingling of wildlife and livestock. In Montana, the presence of brucellosis (Brucella abortus) in free-ranging elk (Cervus canadensis) populations is of significant management concern because of the...Rayl, Nathaniel D.; Proffitt, Kelly M.; Almberg, Emily S.; Jones, Jennifer D.; Merkle, Jerod A.; Gude, Justin A.; Cross, Paul C.
Hidden cost of disease in a free‐ranging ungulate: brucellosis reduces mid‐winter pregnancy in elk
Demonstrating disease impacts on the vital rates of free‐ranging mammalian hosts typically requires intensive, long‐term study. Evidence for chronic pathogens affecting reproduction but not survival is rare, but has the potential for wide‐ranging effects. Accurately quantifying disease‐associated reductions in fecundity is important for advancing...Cotterill, Gavin G.; Cross, Paul C.; Middleton, Arthur D.; Rogerson, Jared D.; Scurlock, Brandon M.; Du Toit, Johan T.
Forecasting for dry and wet avalanches during mixed rain and snow storm events
Natural wet slab avalanches release when rain or melt water decreases snowpack strength, and natural dry slab avalanches release when an increased load overcomes snowpack strength. This study investigates avalanche activity resulting from mixed rain and snow falling on a faceted snowpack. This scenario produced an extensive slab avalanche cycle in...Savage, Scott; Peitzsch, Erich; Trautman, Simon; VandenBos, Benjamin
Detecting snow depth change in avalanche path starting zones using uninhabited aerial systems and structure from motion photogrammetry
Understanding snow depth distribution and change is useful for avalanche forecasting and mitigation, runoff forecasting, and infrastructure planning. Advances in remote sensing are improving the ability to collect snow depth measurements. The development of structure from motion (SfM), a photogrammetry technique, combined with the use of...Peitzsch, Erich H.; Fagre, Daniel B.; Hendrikx, Jordy; Birkeland, Karl W.
Identifying management-relevant research priorities for responding to disease-associated amphibian declines
A research priority can be defined as a knowledge gap that, if resolved, identifies the optimal course of conservation action. We (a group of geographically distributed and multidisciplinary research scientists) used tools from nominal group theory and decision analysis to collaboratively identify and prioritize information...Campbell Grant, Evan H.; Adams, M.J.; Fisher, Robert N.; Grear, Daniel A.; Halstead, Brian J.; Hossack, Blake R.; Muths, Erin L.; Richgels, Katherine L. D.; Russell, Robin E.; Smalling, Kelly L.; Waddle, J. Hardin; Walls, Susan C.; White, C. LeAnn
Effects of persistent energy-related brine contamination on amphibian abundance in national wildlife refuge wetlands
To inform sustainable energy development, it is important to understand the ecological effects of historical and current production practices and the persistence of those effects. The Williston Basin is one of North America's largest oil production areas and overlaps the Prairie Pothole Region, an area densely...Hossack, Blake R.; Smalling, Kelly L.; Anderson, Chauncey W.; Preston, Todd M.; Cozzarelli, Isabelle M.; Honeycutt, R. Ken
Identifying major avalanche years from a regional tree-ring based avalanche chronology for the U.S. Northern Rocky Mountains
Avalanches not only pose a major hazard to people and infrastructure, but also act as an important ecological disturbance. In many mountainous regions in North America, including areas with existing transportation corridors, reliable and consistent avalanche records are sparse or non-existent. Thus, inferring long-term avalanche...Peitzsch, Erich H.; Fagre, Daniel B.; Pederson, Gregory T.; Hendrikx, Jordy; Birkeland, Karl W.; Stahle, Daniel
Impacts of temporal revisit designs on the power to detect trend with a linear mixed model: An application to long-term monitoring of Sierra Nevada lakes
Long-term ecological monitoring programs often use linear mixed models to estimate trend in an ecological indicator sampled across large landscapes. A linear mixed model is versatile for estimating a linear trend in time as well as components of spatial and temporal variationin the case of unbalanced data structures,...Starcevich, Leigh Ann H.; Irvine, Kathryn M.; Heard, Andrea M.
Occupancy modeling species–environment relationships with non‐ignorable survey designs
Statistical models supporting inferences about species occurrence patterns in relation to environmental gradients are fundamental to ecology and conservation biology. A common implicit assumption is that the sampling design is ignorable and does not need to be formally accounted for in analyses. The analyst assumes data are representative of the...Irvine, Kathryn M.; Rodhouse, Thomas J.; Wright, Wilson J.; Olsen, Anthony R.