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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: 1302

Ecological implications of bovine tuberculosis in African Buffalo herds Ecological implications of bovine tuberculosis in African Buffalo herds

Following the recent invasion of bovine tuberculosis (BTB) into the Kruger National Park, South Africa, we conducted a study on the maintenance host, African buffalo, to investigate associations between BTB prevalence and calf:cow ratio, age structure, body condition, and endoparasite load. Statistical analyses compared herds of zero, medium (1–40%), and high (>40%) BTB prevalence. To...
Authors
Alex Caron, Paul C. Cross, Johan T. du Toit

Winter diel habitat use and movement by subadult bull trout in the upper Flathead River, Montana Winter diel habitat use and movement by subadult bull trout in the upper Flathead River, Montana

We evaluated the diel habitat use and movement of subadult bull trout Salvelinus confluentus by use of radiotelemetry during winter in the upper Flathead River, Montana. Of the 13 monitored bull trout, 12 (92%) made at least one diel movement to other habitat locations during their respective day–night tracking surveys and moved an average of 73% of the time. The median distance moved...
Authors
Clint C. Muhlfeld, Steve Glutting, Rick Hunt, Durae Daniels, Brian Marotz

Use of sulfur and nitrogen stable isotopes to determine the importance of whitebark pine nuts to Yellowstone grizzly bears Use of sulfur and nitrogen stable isotopes to determine the importance of whitebark pine nuts to Yellowstone grizzly bears

Whitebark pine (Pinus albicaulis) is a masting species that produces relatively large, fat- and protein-rich nuts that are consumed by grizzly bears (Ursus arctos horribilis). Trees produce abundant nut crops in some years and poor crops in other years. Grizzly bear survival in the Greater Yellowstone Ecosystem is strongly linked to variation in pine-nut availability. Because whitebark...
Authors
L.A. Felicetti, C.C. Schwartz, R. O. Rye, M.A. Haroldson, K.A. Gunther, D.L. Phillips, C.T. Robbins

Spread of hybridization between native westslope cutthroat trout, Oncorhynchus clarki lewisi, and nonnative rainbow trout, Oncorhynchus mykiss Spread of hybridization between native westslope cutthroat trout, Oncorhynchus clarki lewisi, and nonnative rainbow trout, Oncorhynchus mykiss

We examined spatial and temporal patterns of hybridization between native westslope cutthroat trout, Oncorhynchus clarki lewisi, and nonnative rainbow trout, O. mykiss, in streams of the Flathead River system in Montana, U.S.A. We detected hybridization in 24 of 42 sites sampled from 1998 to 2001. We found new Oncorhynchus mykiss introgression in seven of 11 sample populations that were...
Authors
Nathaniel P. Hitt, Christopher A. Frissell, Clint C. Muhlfeld, Fred W. Allendorf

Taking the pulse of mountains: Ecosystem responses to climatic variability Taking the pulse of mountains: Ecosystem responses to climatic variability

An integrated program of ecosystem modeling and field studies in the mountains of the Pacific Northwest (U.S.A.) has quantified many of the ecological processes affected by climatic variability. Paleoecological and contemporary ecological data in forest ecosystems provided model parameterization and validation at broad spatial and temporal scales for tree growth, tree regeneration and...
Authors
Daniel B. Fagre, David L. Peterson, Amy E. Hessl

Fire and amphibians in North America Fire and amphibians in North America

Information on amphibian responses to fire and fuel reduction practices is critically needed due to potential declines of species and the prevalence of new, more intensive fire management practices in North American forests. The goals of this review are to summarize the known and potential effects of fire and fuels management on amphibians and their aquatic habitats, and to identify...
Authors
D. S. Pilliod, R.B. Bury, E.J. Hyde, C.A. Pearl, P.S. Corn

Status of native fishes in the western United States and issues for fire and fuels management Status of native fishes in the western United States and issues for fire and fuels management

Conservation of native fishes and changing patterns in wildfire and fuels are defining challenges for managers of forested landscapes in the western United States. Many species and populations of native fishes have declined in recorded history and some now occur as isolated remnants of what once were larger more complex systems. Land management activities have been viewed as one cause of...
Authors
B. Rieman, D. Lee, D. Burns, Robert E. Gresswell, M. Young, R. Stowell, J. Rinne, P. Howell

Management implications of the ecology of free-roaming horses in semiarid ecosystems of the western United States Management implications of the ecology of free-roaming horses in semiarid ecosystems of the western United States

Compared to other ungulates of North America, free-roaming horses (Equus caballus) possess a unique evolutionary history that has given rise to a distinct suite of behavioral, morphological, and physiological traits. Because of their unique combination of cecal digestion, an elongate head with flexible lips, and non-uniform use of the landscape, horses represent a unique disturbance...
Authors
Erik Beever

Coupling ice-sheet and climate models for simulation of former ice sheets Coupling ice-sheet and climate models for simulation of former ice sheets

This chapter explores the development of coupled climate and ice-sheet models over the past two decades, discusses the current technical and physical capabilities of models, and identifies future work for developing a better understanding of ice-climate events that have punctuated Earth history. The chapter also illustrates the complex behavior of the climate system and the modeling...
Authors
Shawn J. Marshall, David Pollard, Steven W. Hostetler, Peter U. Clark
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