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
Status of amphibians on the Continental Divide:Surveys on a transect from Montana to Colorado, USA
The Rocky Mountain Region of the United States Geological Survey's Amphibian Research and Monitoring Initiative is conducting monitoring of the status of amphibians on a transect that extends along the Continental Divide from Canada to Colorado and comprises four National Parks. Monitoring uses visual encounter surveys to determine site occupancy, with multiple visits to a subset of sites to estim
Authors
P. S. Corn, B. R. Hossack, E. Muths, D.A. Patla, C.R. Peterson, Alisa L. Gallant
An evaluation of weather and disease as causes of decline in two populations of boreal toads
Two populations of boreal toads (Bufo boreas) experienced drastic declines in abundance in the late 1990s. Evidence supported the hypothesis of disease (the chytrid fungus, Batrachochytrium dendrobatidis) as the cause of these declines, but other hypotheses had not been evaluated. We used an 11-year capture–recapture data set to evaluate weather and disease as causes of these declines. We develope
Authors
Rick D. Scherer, Erin L. Muths, Barry R. Noon, Paul Stephen Corn
Disentangling association patterns in fission-fusion societies using African buffalo as an example
A description of the social network of a population aids us in understanding dispersal, the spread of disease, and genetic structure in that population. Many animal populations can be classified as fission–fusion societies, whereby groups form and separate over time. Examples discussed in the literature include ungulates, primates and cetaceans (Lott and Minta, 1983, Whitehead et al., 1991, Henzi
Authors
P.C. Cross, James O. Lloyd-Smith, W.M. Getz
Duelling timescales of host mixing and disease spread determine invasion of disease in structured populations
The epidemic potential of a disease is traditionally assessed using the basic reproductive number, R0. However, in populations with social or spatial structure a chronic disease is more likely to invade than an acute disease with the same R0, because it persists longer within each group and allows for more host movement between groups. Acute diseases ‘perceive’ a more structured host population, a
Authors
P.C. Cross, James O. Lloyd-Smith, P.L.F. Johnson, W.M. Getz
Should we expect population thresholds for wildlife disease?
Host population thresholds for invasion or persistence of infectious disease are core concepts of disease ecology, and underlie on-going and controversial disease control policies based on culling and vaccination. Empirical evidence for these thresholds in wildlife populations has been sparse, however, though recent studies have narrowed this gap. Here we review the theoretical bases for populatio
Authors
James O. Lloyd-Smith, P.C. Cross, C.J. Briggs, M. Daugherty, W.M. Getz, J. Latto, M. Sanchez, A. Smith, A. Swei
Lack of significant changes in the herpetofauna of Theodore Roosevelt National Park, North Dakota, since the 1920s
We surveyed 88 upland wetlands and 12 1-km river sections for amphibians in Theodore Roosevelt National Park, North Dakota, during 2001–2002 to gather baseline data for future monitoring efforts and to evaluate changes in the distribution of species. We compared our results to collections of herpetofauna made during 1920–1922, 1954 and 1978–1979. The boreal chorus frog (Pseudacris maculata) was th
Authors
B. R. Hossack, P. S. Corn, D. S. Pilliod
Changing numbers of spawning cutthroat trout in tributary streams of Yellowstone Lake and estimates of grizzly bears visiting streams from DNA
Spawning Yellowstone cutthroat trout (Oncorhynchus clarki) provide a source of highly digestible energy for grizzly bears (Ursus arctos) that visit tributary streams to Yellowstone Lake during the spring and early summer. During 1985–87, research documented grizzly bears fishing on 61% of the 124 tributary streams to the lake. Using track measurements, it was estimated that a minimum of 44 grizzly
Authors
M.A. Haroldson, K.A. Gunther, Daniel P. Reinhart, S.R. Podruzny, C. Cegelski, L. Waits, T.C. Wyman, J. Smith
Describing spatial pattern in stream networks: A practical approach
The shape and configuration of branched networks influence ecological patterns and processes. Recent investigations of network influences in riverine ecology stress the need to quantify spatial structure not only in a two-dimensional plane, but also in networks. An initial step in understanding data from stream networks is discerning non-random patterns along the network. On the other hand, data
Authors
L.M. Ganio, C.E. Torgersen, R. E. Gresswell
Factors influencing within-watershed genetic variation of coastal cutthroat trout
No abstract available.
Authors
J. E. B. Wofford, R. E. Gresswell, M. A. Banks
Climate change and amphibians
Amphibian life histories are exceedingly sensitive to temperature and precipitation, and there is good evidence that recent climate change has already resulted in a shift to breeding earlier in the year for some species. There are also suggestions that the recent increase in the occurrence of El Niño events has caused declines of anurans in Central America and is linked to elevated mortality of am
Authors
P. S. Corn
The U.S. Geological Survey's Amphibian Research and Monitoring Initiative
The Amphibian Research and Monitoring Initiative (ARMI) began in 2000 as an attempt by the United States Geological Survey to determine the status and trends of amphibians on federal lands in the United States and its territories. ARMI research focuses on determining causes of declines, if observed, developing new techniques to sample populations and analyze data, and disseminating information to
Authors
P. S. Corn, E. Muths, M.J. Adams, C. K. Dodd
Estimated ultraviolet radiation doses in wetlands in six national parks
Ultraviolet-B radiation (UV-B, 280–320-nm wavelengths) doses were estimated for 1024 wetlands in six national parks: Acadia (Acadia), Glacier (Glacier), Great Smoky Mountains (Smoky), Olympic (Olympic), Rocky Mountain (Rocky), and Sequoia/Kings Canyon (Sequoia). Estimates were made using ground-based UV-B data (Brewer spectrophotometers), solar radiation models, GIS tools, field characterization o
Authors
S. A. Diamond, P.C. Trenham, M. J. Adams, B. R. Hossack, R.A. Knapp, L. Stark, D. Bradford, P. S. Corn, K. Czarnowski, P. D. Brooks, D.B. Fagre, B. Breen, N.E. Dentenbeck, K. Tonnessen