Estimation of nitrogen yields and loads from basins draining to Long Island Sound, 1988–98
John R. Mullaney, Gregory E. Schwarz, Elaine C. Todd Trench
2002, Water-Resources Investigations Report 2002-4044
Monitoring data on total nitrogen concentrations and streamflow were used to estimate annual nonpoint nitrogen loads for 1988?98 at 28 monitoring sites and 26 unmonitored basins that drain to Long Island Sound. The estimated total nitrogen yields at monitoring sites were used with basin characteristics and ancillary data to develop a multiple-linear regression equation to estimate nonpoint nitrogen...
Natural and management influences on freshwater inflows and salinity in the San Francisco Estuary at monthly to interannual scales
Noah Knowles
2002, Water Resources Research (38) 25-1-25-11
Understanding the processes controlling the physics, chemistry, and biology of the San Francisco Estuary and their relation to climate variability is complicated by the combined influence on freshwater inflows of natural variability and upstream management. To distinguish these influences, alterations of estuarine inflow due to major reservoirs and freshwater pumping...
Annual primary production: Patterns and mechanisms of change in a nutrient-rich tidal ecosystem
Alan D. Jassby, James E. Cloern, B.E. Cole
2002, Limnology and Oceanography (47) 698-712
Although nutrient supply often underlies long-term changes in aquatic primary production, other regulatory processes can be important. The Sacramento-San Joaquin River Delta, a complex of tidal waterways forming the landward portion of the San Francisco Estuary, has ample nutrient supplies, enabling us to examine alternate regulatory mechanisms over...
Aerial survey methodology for bison population estimation in Yellowstone National Park
Steven C. Hess
2002, Thesis
I developed aerial survey methods for statistically rigorous bison population estimation in Yellowstone National Park to support sound resource management decisions and to understand bison ecology. Survey protocols, data recording procedures, a geographic framework, and seasonal stratifications were based on field observations from February 1998-September 2000. The reliability of this...
Modeling and measuring snow for assessing climate change impacts in Glacier National Park, Montana
Daniel B. Fagre, David J. Selkowitz, Blase Reardon, Karen Holzer, Lisa McKeon
2002, Conference Paper, Proceedings of International Snow Science Workshop
A 12-year program of global change research at Glacier National Park by the U.S. Geological Survey and numerous collaborators has made progress in quantifying the role of snow as a driver of mountain ecosystem processes. Spatially extensive snow surveys during the annual accumulation/ablation cycle covered two mountain watersheds and approximately...
Grizzly bear denning chronology and movements in the Greater Yellowstone Ecosystem
Mark A. Haroldson, Mark A. Ternent, Kerry A. Gunther, Charles C. Schwartz
2002, Ursus (13) 29-38
Den entrance and emergence dates of grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem are important to management agencies that wish to minimize impacts of human activities on bears. Current estimates for grizzly bear denning events use data that were collected from 1975–80. We update these estimates by including...
History of pronghorn population monitoring, research, and management in Yellowstone National Park
Kim A. Keating
2002, Report
Pronghorn antelope in Yellowstone National Park (YNP) persist in a small population that historically has experienced recurrent, sometimes dramatic declines. They apparently are isolated from other pronghorns, depend partly on private lands for winter range, experience heavy predation of fawns, and concentrate during winter in a relatively small area, thereby...
Effects of management practices on wetland birds: Black tern
Amy L. Zimmerman, Jill A. Dechant, Douglas A. Johnson, Christopher M. Goldade, Brent E. Jamison, Betty R. Euliss
2002, Report, Effects of management practices on wetland birds
Information on the habitat requirements and effects of habitat management on wetland birds were summarized from information in more than 500 published and unpublished papers. A range map is provided to indicate the relative densities of the species in North America, based on Breeding Bird Survey (BBS) data. Although the...
Grizzly bear denning and potential conflict areas in the Greater Yellowstone Ecosystem
Shannon Podruzny, Steve Cherry, Charles C. Schwartz, Lisa Landenburger
2002, Ursus (13) 19-28
Increasing winter use of steep, high-elevation terrain by backcountry recreationists has elevated concern about disturbance of denning grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem (GYE). To help identify areas where such conflicts might occur, we developed a spatially explicit model to predict potential denning areas in the GYE....
Effects of management practices on wetland birds: Yellow Rail
Christopher M. Goldade, Jill A. Dechant, Douglas H. Johnson, Amy L. Zimmerman, Brent E. Jamison, James O. Church, Betty R. Euliss
2002, Report, Effects of management practices on wetland birds
Information on the habitat requirements and effects of habitat management on wetland birds were summarized from information in more than 500 published and unpublished papers. A range map is provided to indicate the relative densities of the species in North America, based on Breeding Bird Survey (BBS) data. Although the...
Effects of management practices on wetland birds: Virginia rail
Amy L. Zimmerman, Jill A. Dechant, Brent E. Jamison, Douglas H. Johnson, Christopher M. Goldade, James O. Church, Betty R. Euliss
2002, Report, Effects of management practices on wetland birds
Information on the habitat requirements and effects of habitat management on wetland birds were summarized from information in more than 500 published and unpublished papers. A range map is provided to indicate the relative densities of the species in North America, based on Breeding Bird Survey (BBS) data. Although the...
Effects of management practices on wetland birds: American Avocet
Jill A. Dechant, Amy L. Zimmerman, Douglas H. Johnson, Christopher M. Goldade, Brent E. Jamison, Betty R. Euliss
2002, Report, Effects of management practices on wetland birds
Information on the habitat requirements and effects of habitat management on wetland birds were summarized from information in more than 500 published and unpublished papers. A range map is provided to indicate the relative densities of the species in North America, based on Breeding Bird Survey (BBS) data. Although the...
Double sampling to estimate density and population trends in birds
Jonathan Bart, Susan L. Earnst
2002, The Auk (119) 36-45
We present a method for estimating density of nesting birds based on double sampling. The approach involves surveying a large sample of plots using a rapid method such as uncorrected point counts, variable circular plot counts, or the recently suggested double-observer method. A subsample of those plots is also surveyed...
Wisconsin: A summary of cooperative water-resources investigations 2002
Water Resources Division, U.S. Geological Survey, Wisconsin Department of Natural Resources
2002, Report
The objectives of this study are to provide continuous discharge records for selected rivers at specific sites to supply the needs for regulation, analytical studies, definition of statistical properties, trends analysis, determination of the occurrence, and distribution of water in streams for planning. The project is also designed to determine...
Estimating site occupancy rates when detection probabilities are less than one
D.I. MacKenzie, J.D. Nichols, G.B. Lachman, Sam Droege, J. Andrew Royle, C.A. Langtimm
2002, Ecology (83) 2248-2255
Nondetection of a species at a site does not imply that the species is absent unless the probability of detection is 1. We propose a model and likelihood-based method for estimating site occupancy rates when detection probabilities are < 1. The model provides a flexible framework enabling covariate information to...
Sources of variation in breeding-ground fidelity of mallards (Anas platyrhynchos)
P.F. Doherty Jr., J.D. Nichols, J. Tautin, J.E. Voelzer, G.W. Smith, D.S. Benning, V.R. Bentley, J.K. Bidwell, K.S. Bollinger, A.R. Brazda, E.K. Buelna, J.R. Goldsberry, R.J. King, F.H. Roetker, J.W. Solberg, P.P. Thorpe, J.S. Wortham
2002, Behavioral Ecology (13) 543-550
Generalizations used to support hypotheses about the evolution of fidelity to breeding areas in birds include the tendency for fidelity to be greater in adult birds than in yearlings. In ducks, in contrast to most bird species, fidelity is thought to be greater among females than males. Researchers...
α1-Antitrypsin polymorphism and systematics of eastern North American wolves
L.D. Mech, N.E. Federoff
2002, Canadian Journal of Zoology (80) 961-963
We used data on the polymorphic status of α1-antitrypsin (α1AT) to study the relationship of Minnesota wolves to the gray wolf (Canis lupus), which was thought to have evolved in Eurasia, and to red wolves (Canis rufus) and coyotes (Canis latrans), which putatively evolved in North America. Recent evidence had...
Sources of variation in survival and breeding site fidelity in three species of European ducks
Peter Blums, J.D. Nichols, J.E. Hines
2002, Journal of Animal Ecology (71) 438-450
1. We used long-term capture-recapture-recovery data and a modelling approach developed by Burnham (1993) to test a priori predictions about sources of variation in annual survival rates and fidelity within a population of individually marked females in three species of European ducks from a breeding ground study site in Latvia....
Hierarchical modeling of population stability and species group attributes from survey data
J.R. Sauer, W.A. Link
2002, Ecology (83) 1743-1751
Many ecological studies require analysis of collections of estimates. For example, population change is routinely estimated for many species from surveys such as the North American Breeding Bird Survey (BBS), and the species are grouped and used in comparative analyses. We developed a hierarchical model for estimation...
A removal model for estimating detection probabilities from point-count surveys
G.L. Farnsworth, K. H. Pollock, J.D. Nichols, T.R. Simons, J.E. Hines, J.R. Sauer
2002, The Auk (119) 414-425
Use of point-count surveys is a popular method for collecting data on abundance and distribution of birds. However, analyses of such data often ignore potential differences in detection probability. We adapted a removal model to directly estimate detection probability during point-count surveys. The model assumes that singing frequency is a...
The importance of functional form in optimal control solutions of problems in population dynamics
M.C. Runge, Fred A. Johnson
2002, Ecology (83) 1357-1371
Optimal control theory is finding increased application in both theoretical and applied ecology, and it is a central element of adaptive resource management. One of the steps in an adaptive management process is to develop alternative models of system dynamics, models that are all reasonable in light of available...
Disentangling sampling and ecological explanations underlying species-area relationships
E. Cam, J.D. Nichols, J.E. Hines, J.R. Sauer, R. Alpizar-Jara, C.H. Flather
2002, Ecology (83) 1118-1130
We used a probabilistic approach to address the influence of sampling artifacts on the form of species-area relationships (SARs). We developed a model in which the increase in observed species richness is a function of sampling effort exclusively. We assumed that effort depends on area sampled, and we...
Of bugs and birds: Markov Chain Monte Carlo for hierarchical modeling in wildlife research
William A. Link, Emmanuelle Cam, James D. Nichols, Evan G. Cooch
2002, Journal of Wildlife Management (66) 277-291
Markov chain Monte Carlo (MCMC) is a statistical innovation that allows researchers to fit far more complex models to data than is feasible using conventional methods. Despite its widespread use in a variety of scientific fields, MCMC appears to be underutilized in wildlife applications. This may be due to a...
On the estimation of species richness based on the accumulation of previously unrecorded species
E. Cam, J.D. Nichols, J.R. Sauer, J.E. Hines
2002, Ecography (25) 102-108
Estimation of species richness of local communities has become an important topic in community ecology and monitoring. Investigators can seldom enumerate all the species present in the area of interest during sampling sessions. If the location of interest is sampled repeatedly within a short time period, the number...
Variation in survivorship of a migratory songbird throughout its annual cycle
T. Scott Sillett, Richard T. Holmes
2002, Journal of Animal Ecology (71) 296-308
1. Demographic data from both breeding and non-breeding periods are needed to manage populations of migratory birds, many of which are declining in abundance and are of conservation concern. Although habitat associations, and to a lesser extent, reproductive biology, are known for many migratory species, few studies have measured survival...
