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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: 1316

Growth and defense characteristics of whitebark pine (Pinus albicaulis) and lodgepole pine (Pinus contorta var latifolia) in a high-elevation, disturbance-prone mixed-conifer forest in northwestern Montana, USA Growth and defense characteristics of whitebark pine (Pinus albicaulis) and lodgepole pine (Pinus contorta var latifolia) in a high-elevation, disturbance-prone mixed-conifer forest in northwestern Montana, USA

Recent, widespread tree mortality in the western U.S. resulting from changes in climate, pathogens, insect activity, and forest management practices has led to concerns for many ecologically and culturally important species. Within conifers, resin-based defenses have long been recognized as a primary defense mechanism against a variety of insects and pathogens. Oleoresin produced by...
Authors
Nicholas E. Kichas, Amy M. Trowbridge, Kenneth F. Raffa, Shealyn C. Malone, Sharon M. Hood, Richard G. Everett, David B. McWethy, Gregory T. Pederson

Enigmatic near‐extirpation in a boreal toad metapopulation in northwestern Montana Enigmatic near‐extirpation in a boreal toad metapopulation in northwestern Montana

North America's protected lands harbor biodiversity and provide habitats where species threatened by a variety of stressors in other environments can thrive. Yet disease, climate change, and other threats are not limited by land management boundaries and can interact with conditions within protected landscapes to affect sensitive populations. We examined the population dynamics of a...
Authors
Rebecca M. McCaffery, Robin E. Russell, Blake R. Hossack

Anthropogenic edge effects in habitat selection by sun bears in a protected area Anthropogenic edge effects in habitat selection by sun bears in a protected area

Wildlife populations in southeast Asia are increasingly experiencing a broad array of anthropogenic threats, and mammalian carnivores are particularly vulnerable. Populations of the Malayan sun bear Helarctos malayanus are estimated to have declined by 30% over the last 30 years from forest conversion to industrial plantations and mortality associated with human–bear conflicts and...
Authors
T. L Tee, Frank T. van Manen, P. Kretzschmar, S. P. Sharp, S. T. Wong, S. Gadas, S. Ratnayeke

Cold tolerance of mountain stoneflies (Plecoptera: Nemouridae) from the high Rocky Mountains Cold tolerance of mountain stoneflies (Plecoptera: Nemouridae) from the high Rocky Mountains

How aquatic insects cope with cold temperatures is poorly understood. This is particularly true for high-elevation species, which often experience a seasonal risk of freezing. In the Rocky Mountains, nemourid stoneflies (Plecoptera: Nemouridae) are a major component of mountain stream biodiversity and are typically found in streams fed by glaciers and snowfields, which are rapidly...
Authors
Scott Hotaling, Alisha A. Shah, Michael E. Dillon, J. Joseph Giersch, Lusha M. Tronstad, Debra S. Finn, H. Arthur Woods, Joanna L. Kelley

Evaluation of remote site incubators to incubate wild- and hatchery-origin Westslope Cutthroat Trout embryos Evaluation of remote site incubators to incubate wild- and hatchery-origin Westslope Cutthroat Trout embryos

Fish managers must weigh trade-offs among cost, speed, efficiency, and ecological adaptation when deciding how to translocate native salmonids to either establish or genetically augment populations. Remote site incubators (RSIs) appear to be a reasonable strategy, but large-scale evaluations of this method have been limited. We used 129 RSIs to incubate >35,700 eyed embryos of Westslope...
Authors
Bradley B. Shepard, Patrick Clancey, Lee M. Nelson, Carter Kruse, Robert K. Al-Chokhachy, Daniel Drinan, Alexander V. Zale

Integrating ecological impacts: Perspectives on drought in the Upper Missouri Headwaters, Montana, United States Integrating ecological impacts: Perspectives on drought in the Upper Missouri Headwaters, Montana, United States

Drought is a complex challenge experienced in specific locations through diverse impacts, including ecological impacts. Different professionals involved in drought preparedness and response approach the problem from different points of view, which means they may or may not recognize ecological impacts. This study examines the extent to which interviewees perceive ecological drought in...
Authors
Amanda E. Cravens, Jamie McEvoy, Dionne Zoanni, Shelley Crausbay, Aaron R. Ramirez, Ashley E. Cooper

Evaluation of connectivity among black bear populations in Georgia Evaluation of connectivity among black bear populations in Georgia

Habitat fragmentation and loss contribute to isolation of wildlife populations and increased extinction risks for various species, including many large carnivores. We studied a small and isolated population of American black bears (Ursus americanus) that is of conservation concern in central Georgia, USA (i.e., central Georgia bear population [CGBP]). Our goal was to evaluate the...
Authors
Michael J. Hooker, Joseph D. Clark, Bobby T Bond, Michael J Chamberlain

Effects of supplemental feeding on the fecal bacterial communities of Rocky Mountain elk in the Greater Yellowstone Ecosystem Effects of supplemental feeding on the fecal bacterial communities of Rocky Mountain elk in the Greater Yellowstone Ecosystem

Supplemental feeding of wildlife is a common practice often undertaken for recreational or management purposes, but it may have unintended consequences for animal health. Understanding cryptic effects of diet supplementation on the gut microbiomes of wild mammals is important to inform conservation and management strategies. Multiple laboratory studies have demonstrated the importance of...
Authors
Claire E Couch, Benjamin Wise, Brandon Scurlock, Jared D. Rogerson, Rebecca K. Fuda, Eric K Cole, Kimberly E Szcodronski, Adam Sepulveda, Patrick R. Hutchins, Paul C. Cross

A reassessment of Chao2 estimates for population monitoring of grizzly bears in the Greater Yellowstone Ecosystem A reassessment of Chao2 estimates for population monitoring of grizzly bears in the Greater Yellowstone Ecosystem

The Yellowstone Ecosystem Subcommittee (YES) asked the Interagency Grizzly Bear Study Team (IGBST) to re-assess a technique used in annual population estimation and trend monitoring of grizzly bears in the Greater Yellowstone Ecosystem (GYE). This technique is referred to as the Chao2 approach and estimates the number of females with cubs-of-the-year (hereafter, females with cubs) and...
Authors
Frank T. van Manen, Michael R. Ebinger, Mark A. Haroldson, Daniel D. Bjornlie, Justin Clapp, Daniel J. Thompson, Kevin L. Frey, Cecily M. Costello, Curtis Hendricks, Jeremy M. Nicholson, Kerry A. Gunther, Katharine R. Wilmot, Hilary Cooley, Jennifer Fortin-Noreus, Pat Hnilicka, Daniel B. Tyers

Advancements in analytical approaches improve whitebark pine monitoring results Advancements in analytical approaches improve whitebark pine monitoring results

Long-term monitoring programs track the status and trends of species in increasingly vulnerable environments. These monitoring results provide critical information for evaluating, understanding, and managing natural resources. To accurately interpret if and how conditions may be changing for select ecological indicators, it is essential that monitoring programs adopt methods to ensure...
Authors
Erin Shanahan, Kathryn M. Irvine

Quantifying energetic costs and defining energy landscapes experienced by grizzly bears Quantifying energetic costs and defining energy landscapes experienced by grizzly bears

Animal movements are major determinants of energy expenditure and ultimately the cost–benefit of landscape use. Thus, we sought to understand those costs and how grizzly bears (Ursus arctos) move in mountainous landscapes. We trained captive grizzly bears to walk on a horizontal treadmill and up and down 10% and 20% slopes. The cost of moving upslope increased linearly with speed and...
Authors
Anthony M. Carnahan, Frank T. van Manen, Mark A. Haroldson, Gordon Stenhouse, Charles T. Robbins
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