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: 1216
Using bioenergetics modeling to estimate consumption of native juvenile salmonids by nonnative northern pike in the Upper Flathead River System, Montana
Introductions of nonnative northern pike Esox lucius have created recreational fisheries in many waters in the United States and Canada, yet many studies have shown that introduced northern pike may alter the composition and structure of fish communities through predation. We estimated the abundance of nonnative northern pike (2002-2003) and applied food habits data (1999-2003) to estimate their a
Authors
C.C. Muhlfeld, D.H. Bennett, Steinhorst R. Kirk, B. Marotz, M. Boyer
Challenges of DNA-based mark-recapture studies of American black bears
We explored whether genetic sampling would be feasible to provide a region-wide population estimate for American black bears (Ursus americanus) in the southern Appalachians, USA. Specifically, we determined whether adequate capture probabilities (p >0.20) and population estimates with a low coefficient of variation (CV <20%) could be achieved given typical agency budget and personnel constraints.
Authors
K.E. Settlage, F.T. Van Manen, J. D. Clark, T.L. King
Wildlife health initiatives in Yellowstone National Park
No abstract available.
Authors
Paul C. Cross, G. Plumb
Spatial design and strength of spatial signal: Effects on covariance estimation
In a spatial regression context, scientists are often interested in a physical interpretation of components of the parametric covariance function. For example, spatial covariance parameter estimates in ecological settings have been interpreted to describe spatial heterogeneity or “patchiness” in a landscape that cannot be explained by measured covariates. In this article, we investigate the influe
Authors
Kathryn M. Irvine, Alix I. Gitelman, Jennifer A. Hoeting
Results of chemical analyses of soil, shale, and soil/shale extract from the Mancos Shale formation in the Gunnison Gorge National Conservation Area, southwestern Colorado, and at Hanksville, Utah
Results of chemical and some isotopic analyses of soil, shale, and water extracts collected from the surface, trenches, and pits in the Mancos Shale are presented in this report. Most data are for sites on the Gunnison Gorge National Conservation Area (GGNCA) in southwestern Colorado. For comparison, data from a few sites from the Mancos landscape near Hanksville, Utah, are included. Twelve trench
Authors
Michele L.W. Tuttle, Juli Fahy, Richard I. Grauch, Bridget A. Ball, Geneva W. Chong, John G. Elliott, John J. Kosovich, Keith E. Livo, Lisa L. Stillings
Evaluating shading bias in malaise and intercept traps
Foresters are increasingly focusing on landscape level management regimes. At the landscape level, managed acreage may differ substantially in structure and micro-climatic conditions. Trapping is a commonly used method to evaluate changes in insect communities across landscapes. Among those trapping techniques, Malaise and window-pane traps are conveniently deployed to collect large numbers of ins
Authors
Kathryn M. Irvine, Stephen A. Woods
Longitudinal patterns of fish assemblages, aquatic habitat, and water temperature in the Lower Crooked River, Oregon
The Lower Crooked River is a remarkable groundwater-fed stream flowing through vertical basalt canyons in the Deschutes River Valley ecoregion in central Oregon (Pater and others, 1998). The 9-mile section of the river between the Crooked River National Grasslands boundary near Ogden Wayside and river mile (RM) 8 is protected under the National Wild and Scenic Rivers Act (16 U.S.C. 1271-1287) for
Authors
Christian E. Torgersen, David P. Hockman-Wert, Douglas S. Bateman, David W. Leer, Robert E. Gresswell
Mechanisms for an ∼7‐kyr climate and sea‐level oscillation during marine isotope stage 3
No abstract available.
Authors
Peter U. Clark, Steven W. Hostetler, N. G. Pisias, Andreas Schmittner, K. J. Meissner
Yellowstone grizzly bear investigations: Annual report of the Interagency Grizzly Bear Study Team, 2006
The contents of this Annual Report summarize results of monitoring and research from the 2006 field season. The report also contains a summary of nuisance grizzly bear (Ursus arctos horribilis) management actions.
The Interagency Grizzly Bear Study Team (IGBST) continues to work on issues associated with counts of unduplicated females with cubs-of- the-year (COY). These counts are used to establis
Influences of geomorphology and geology on alpine treeline in the American West - More important than climatic influences?
The spatial distribution and pattern of alpine treeline in the American West reflect the overarching influences of geological history, lithology and structure, and geomorphic processes and landforms, and geologic and geomorphic factors—both forms and processes—can control the spatiotemporal response of the ecotone to climate change. These influences occur at spatial scales ranging from the contine
Authors
D.R. Butler, G.P. Malanson, S. J. Walsh, D.B. Fagre
Population growth of Yellowstone grizzly bears: Uncertainty and future monitoring
Grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem of the US Rocky Mountains have recently increased in numbers, but remain vulnerable due to isolation from other populations and predicted reductions in favored food resources. Harris et al. (2006) projected how this population might fare in the future under alternative survival rates, and in doing so estimated the rate of population
Authors
R.B. Harris, Gary C. White, C.C. Schwartz, M.A. Haroldson
A comparison of protocols and observer precision for measuring physical stream attributes
Stream monitoring programs commonly measure physical attributes to assess the effect of land management on stream habitat. Variability associated with the measurement of these attributes has been linked to a number of factors, but few studies have evaluated variability due to differences in protocols. We compared six protocols, five used by the U.S. Department of Agriculture Forest Service and one
Authors
H.W. Whitacre, B.B. Roper, J. L. Kershner