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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

Forecasting for natural avalanches during spring opening of Going-to-the-Sun Road, Glacier National Park, Montana, USA

The annual spring opening of the Going-to-the-Sun Road in Glacier National Park presents a unique avalanche forecasting challenge. The highway traverses dozens of avalanche paths mid-track in a 23-kilometer section that crosses the Continental Divide. Workers removing seasonal snow and avalanche debris are exposed to paths that can produce avalanches of destructive class 4. The starting zones for
Authors
Blase Reardon, Chris Lundy

Modeling survival: application of the Andersen-Gill model to Yellowstone grizzly bears

 Wildlife ecologists often use the Kaplan-Meier procedure or Cox proportional hazards model to estimate survival rates, distributions, and magnitude of risk factors. The Andersen-Gill formulation (A-G) of the Cox proportional hazards model has seen limited application to mark-resight data but has a number of advantages, including the ability to accommodate left-censored data, time-varying covariat
Authors
Christopher J. Johnson, Mark S. Boyce, Charles C. Schwartz, Mark A. Haroldson

What limits the Serengeti zebra population?

The populations of the ecologically dominant ungulates in the Serengeti ecosystem (zebra, wildebeest and buffalo) have shown markedly different trends since the 1960s: the two ruminants both irrupted after the elimination of rinderpest in 1960, while the zebras have remained stable. The ruminants are resource limited (though parts of the buffalo population have been limited by poaching since the 1
Authors
Sophie Grange, Patrick Duncan, Jean-Michel Gaillard, Anthony R.E. Sinclair, Peter J. Gogan, Craig Packer, Heribert Hofer, East Marion

Ecological response to global climatic change

Climate change and ecological change go hand in hand. Because we value our ecological environment, any change has the potential to be a problem. Geographers have been drawn to this challenge, and have been successful in addressing it, because the primary ecological response to climate changes in the past — the waxing and waning of the great ice sheets over the past 2 million years – was the changi
Authors
G.P. Malanson, D.R. Butler, S. J. Walsh

Relative spatial distributions and habitat use patterns of sympatric moose and white-tailed deer in Voyageurs National Park, Minnesota

We examined the distribution and home range characteristics of moose (Alces alces) and white-tailed deer (Odocoileus virginianus) at Voyageurs National Park, Minnesota. Pellet count transects revealed low densities of moose and higher densities of white-tailed deer, and provided evidence of partial spatial segregation between moose and white-tailed deer possibly due to habitat heterogeneity. Ther
Authors
M. Cobb, P.J.P. Gogan, K.D. Kozie, E.M. Olexa, R.L. Lawrence, W.T. Route

Use of naturally occurring mercury to determine the importance of cutthroat trout to Yellowstone grizzly bears

Spawning cutthroat trout (Oncorhynchus clarki (Richardson, 1836)) are a potentially important food resource for grizzly bears (Ursus arctos horribilis Ord, 1815) in the Greater Yellowstone Ecosystem. We developed a method to estimate the amount of cutthroat trout ingested by grizzly bears living in the Yellowstone Lake area. The method utilized (i) the relatively high, naturally occurring concentr
Authors
L.A. Felicetti, C.C. Schwartz, R. O. Rye, K.A. Gunther, J. G. Crock, M.A. Haroldson, L. Waits, C.T. Robbins

Reproductive maturation and senescence in the female brown bear

Changes in age-specific reproductive rates can have important implications for managing populations, but the number of female brown (grizzly) bears (Ursus arctos) observed in any one study is usually inadequate to quantify such patterns, especially for older females and in hunted areas. We examined patterns of reproductive maturation and senescence in female brown bears by combining data from 20 s
Authors
Charles C. Schwartz, Kim A. Keating, Harry V. Reynolds III, Victor G. Barnes, Richard A. Sellers, J. E. Swenson, Sterling D. Miller, B. N. McLellan, Jeffrey A. Keay, Robert McCann, Michael Gibeau, Wayne F. Wakkinen, Richard D. Mace, Wayne Kasworm, Rodger Smith, Steven Herrero

Modeling paleoclimates

Paleoclimatic data and climate models play a complimentary role in understanding climate change. This chapter provides an overview of the process of climate-system modeling, presents the taxonomy of the models recently applied in the study of Quaternary climate change and variation, and discusses the development of climate modeling since the 1965 International Union for Quaternary Science (INQUA)
Authors
Patrick J Bartlein, Steven W. Hostetler

Predicting rare plant occurrence in Great Smoky Mountains National Park, USA

We investigated the applicability of biometric habitat modeling to rare plant inventory and conservation by developing and field testing a geographically explicit model for Cardamine clematitis Shuttleworth ex A. Gray (mountain bittercress), an endemic plant of the southern Blue Ridge Mountains, USA. For each of 187 confirmed coordinates for C. clematitis in Great Smoky Mountains National Park, 13
Authors
John R. Boetsch, Frank T. van Manen, Joseph D. Clark

Pleistocene glaciations of the Rocky Mountains

This chapter presents the status of Rocky Mountain glacial studies in 1965 and progress from that time to the present. The Rocky Mountains and the adjacent Basin and Range of the United States consist of about 100 ranges distributed in a northwest trending belt 2,000 km long and 200–800 km wide. In 1965, Rocky Mountain glacial subdivisions and correlations are closely linked with those of the mid-
Authors
Kenneth L. Pierce

Grizzly bear Ursus arctos

No abstract available.
Authors
C.C. Schwartz, S.D. Miller, M.A. Haroldson

Mitochondrial phylogeography of moose (Alces alces) in North America

Nucleotide variation was assessed from the mitochondrial control region of North American moose (Alces alces) to test predictions of a model of range expansion by stepping-stone dispersal and to determine whether patterns of genetic variation support the current recognition of 4 subspecies. Haplotypes formed a star phylogeny indicative of a recent expansion of populations. Values of nucleotide and
Authors
Kris J. Hundertmark, R. Terry Bowyer, Gerald F. Shields, Charles C. Schwartz