James Nichols, Ph.D. (Former Employee)
Science and Products
Development of Methods Associated with Animal Population Dynamics
The Challenge: Conservation and management of natural animal populations requires knowledge of their dynamics and associated environmental and management influences. Specifically, informed management requires periodic estimates of system state (e.g., population size) and models for projecting consequences of management actions for subsequent state dynamics. However, it is very difficult to draw...
Development of Patch Occupancy Models for Assessing the Spatial Distribution of Organisms
The Challenge: A variety of important questions about the conservation and management of natural resources requires information about the spatial distribution of organisms. For species of conservation concern, the size of a species’ range is a criterion used to assign species status as threatened or endangered. For invasive species and disease organisms, the dynamics of the species range expansion...
Statistical Research for the USGS - Amphibian Research and Monitoring Initiative
The Challenge: Since its inception in 2002 the USGS Amphibian Research and Monitoring Initiative (ARMI) has taken the lead in monitoring amphibian populations on Department of Interior lands. ARMI scientists work on a broad spectrum of species and management issues to address the core causes of amphibian declines. In many cases, research requires complex study designs and innovative methods. A key...
Evaluation of Potential Offshore Wind Projects in the Northeastern U.S. on Endangered Roseate Terns: Who is at Risk and When?
The Challenge: Terns in coastal areas of the Northeastern US likely will be impacted by construction and operation of offshore wind turbines. The “Cape Cod & Islands” (CCMA) area of Massachusetts is a particularly important area for the endangered Northwest Atlantic Roseate Tern (ROST) population as most ROSTs from throughout the breeding range (Nova Scotia to Long Island, New York) congregate...
Avian Indicators of Climate Change Based on the North American Breeding Bird Survey
Appropriate ecological indicators of climate change can be used to measure concurrent changes in ecological systems, inform management decisions, and potentially to project the consequences of climate change. However, many of the available indicators for North American birds do not account for imperfect observation. We proposed to use correlated-detection occupancy models to develop...
SERAP: Assessment of Climate and Land Use Change Impacts on Terrestrial Species
Researchers from North Carolina State University and the USGS integrated models of urbanization and vegetation dynamics with the regional climate models to predict vegetation dynamics and assess how landscape change could impact priority species, including North American land birds. This integrated ensemble of models can be used to predict locations where responses to climate change are...
Filter Total Items: 418
Intra-guild compensation regulates species richness in desert rodents: comment Intra-guild compensation regulates species richness in desert rodents: comment
No abstract available.
Authors
J.D. Nichols, J.E. Hines, J.R. Sauer, T. Boulinier, E. Cam
Variation in probability of first reproduction of Weddell seals Variation in probability of first reproduction of Weddell seals
Summary 1. For many species, when to begin reproduction is an important life-history decision that varies by individual and can have substantial implications for lifetime reproductive success and fitness. 2. We estimated age-specific probabilities of first-time breeding and modelled variation in these rates to determine age at first reproduction and understand why it varies in a...
Authors
G.L. Hadley, J.J. Rotella, R.A. Garrott, J.D. Nichols
The role of local populations within a landscape context: Defining and classifying sources and sinks The role of local populations within a landscape context: Defining and classifying sources and sinks
The interaction of local populations has been the focus of an increasing number of studies in the past 30 years. The study of source-sink dynamics has especially generated much interest. Many of the criteria used to distinguish sources and sinks incorporate the process of apparent survival (i.e., the combined probability of true survival and site fidelity) but not emigration. These...
Authors
J.P. Runge, M.C. Runge, J.D. Nichols
Assessing tiger population dynamics using photographic capture-recapture sampling Assessing tiger population dynamics using photographic capture-recapture sampling
Although wide-ranging, elusive, large carnivore species, such as the tiger, are of scientific and conservation interest, rigorous inferences about their population dynamics are scarce because of methodological problems of sampling populations at the required spatial and temporal scales. We report the application of a rigorous, noninvasive method for assessing tiger population dynamics to...
Authors
K. U. Karanth, J.D. Nichols, S. Kumar, J.E. Hines
Adaptive harvest management of North American waterfowl populations - recent successes and future prospects Adaptive harvest management of North American waterfowl populations - recent successes and future prospects
The history of North American waterfowl harvest management has been characterized by attempts to use population monitoring data to make informed harvest management decisions. Early attempts can be characterized as intuitive decision processes, and later efforts were guided increasingly by population models and associated predictions. In 1995, a formal adaptive management process was...
Authors
J.D. Nichols, M.C. Runge, Fred A. Johnson, B. Kenneth Williams
Occupancy Estimation and Modeling : Inferring Patterns and Dynamics of Species Occurrence Occupancy Estimation and Modeling : Inferring Patterns and Dynamics of Species Occurrence
This is the first book to examine the latest methods in analyzing presence/absence data surveys. Using four classes of models (single-species, single-season; single-species, multiple season; multiple-species, single-season; and multiple-species, multiple-season), the authors discuss the practical sampling situation, present a likelihood-based model enabling direct estimation of the...
Authors
D.I. MacKenzie, J.D. Nichols, J. Andrew Royle, K. H. Pollock, L.L. Bailey, J.E. Hines
Status and trends in demography of northern spotted owls, 1985-2003 Status and trends in demography of northern spotted owls, 1985-2003
We analyzed demographic data from northern spotted owls (Strix occidentalis caurina) from 14 study areas in Washington, Oregon, and California for 1985-2003. The purpose of our analyses was to provide an assessment of the status and trends of northern spotted owl populations throughout most of their geographic range. The 14 study areas made up approximately 12% of the range of the...
Authors
R.G. Anthony, E.D. Forsman, A.B. Franklin, David R. Anderson, K.P. Burnham, Gary C. White, C.J. Schwarz, J.D. Nichols, J.E. Hines, G.S. Olson, S.H. Ackers, L.S. Andrews, B.L. Biswell, P.C. Carlson, L.V. Diller, K.M. Dugger, K.E. Fehring, T.L. Fleming, R.P. Gerhardt, S.A. Gremel, R. J. Gutierrez, P.J. Happe, D.R. Herter, J.M. Higley, R.B. Horn, L.L. Irwin, P.J. Loschl, J.A. Reid, S.G. Sovern
Comparative dynamics of avian communities across edges and interiors of North American ecoregions Comparative dynamics of avian communities across edges and interiors of North American ecoregions
Aim Based on a priori hypotheses, we developed predictions about how avian communities might differ at the edges vs. interiors of ecoregions. Specifically, we predicted lower species richness and greater local turnover and extinction probabilities for regional edges. We tested these predictions using North American Breeding Bird Survey (BBS) data across nine ecoregions over a 20-year...
Authors
K.K. Karanth, J.D. Nichols, J.R. Sauer, J.E. Hines
Individual quality, survival variation and patterns of phenotypic selection on body condition and timing of nesting in birds Individual quality, survival variation and patterns of phenotypic selection on body condition and timing of nesting in birds
Questions about individual variation in “quality” and fitness are of great interest to evolutionary and population ecologists. Such variation can be investigated using either a random effects approach or an approach that relies on identifying observable traits that are themselves correlated with fitness components. We used the latter approach with data from 1,925 individual females of...
Authors
Peter Blums, James D. Nichols, James E. Hines, Mark S. Lindberg, Aivars Mednis
Improving inferences in population studies of rare species that are detected imperfectly Improving inferences in population studies of rare species that are detected imperfectly
For the vast majority of cases, it is highly unlikely that all the individuals of a population will be encountered during a study. Furthermore, it is unlikely that a constant fraction of the population is encountered over times, locations, or species to be compared. Hence, simple counts usually will not be good indices of population size. We recommend that detection probabilities (the...
Authors
Darry I. MacKenzie, James D. Nichols, N. Sutton, K. Kawanishi, Larissa Bailey
Assessing spatial coupling in complex population dynamics using mutual prediction and continuity statistics Assessing spatial coupling in complex population dynamics using mutual prediction and continuity statistics
A number of important questions in ecology involve the possibility of interactions or ?coupling? among potential components of ecological systems. The basic question of whether two components are coupled (exhibit dynamical interdependence) is relevant to investigations of movement of animals over space, population regulation, food webs and trophic interactions, and is also useful in the...
Authors
J.M. Nichols, L. Moniz, J.D. Nichols, L.M. Pecora, E. Cooch
Modern open-population capture-recapture models Modern open-population capture-recapture models
No abstract available.
Authors
J.D. Nichols
Science and Products
Development of Methods Associated with Animal Population Dynamics
The Challenge: Conservation and management of natural animal populations requires knowledge of their dynamics and associated environmental and management influences. Specifically, informed management requires periodic estimates of system state (e.g., population size) and models for projecting consequences of management actions for subsequent state dynamics. However, it is very difficult to draw...
Development of Patch Occupancy Models for Assessing the Spatial Distribution of Organisms
The Challenge: A variety of important questions about the conservation and management of natural resources requires information about the spatial distribution of organisms. For species of conservation concern, the size of a species’ range is a criterion used to assign species status as threatened or endangered. For invasive species and disease organisms, the dynamics of the species range expansion...
Statistical Research for the USGS - Amphibian Research and Monitoring Initiative
The Challenge: Since its inception in 2002 the USGS Amphibian Research and Monitoring Initiative (ARMI) has taken the lead in monitoring amphibian populations on Department of Interior lands. ARMI scientists work on a broad spectrum of species and management issues to address the core causes of amphibian declines. In many cases, research requires complex study designs and innovative methods. A key...
Evaluation of Potential Offshore Wind Projects in the Northeastern U.S. on Endangered Roseate Terns: Who is at Risk and When?
The Challenge: Terns in coastal areas of the Northeastern US likely will be impacted by construction and operation of offshore wind turbines. The “Cape Cod & Islands” (CCMA) area of Massachusetts is a particularly important area for the endangered Northwest Atlantic Roseate Tern (ROST) population as most ROSTs from throughout the breeding range (Nova Scotia to Long Island, New York) congregate...
Avian Indicators of Climate Change Based on the North American Breeding Bird Survey
Appropriate ecological indicators of climate change can be used to measure concurrent changes in ecological systems, inform management decisions, and potentially to project the consequences of climate change. However, many of the available indicators for North American birds do not account for imperfect observation. We proposed to use correlated-detection occupancy models to develop...
SERAP: Assessment of Climate and Land Use Change Impacts on Terrestrial Species
Researchers from North Carolina State University and the USGS integrated models of urbanization and vegetation dynamics with the regional climate models to predict vegetation dynamics and assess how landscape change could impact priority species, including North American land birds. This integrated ensemble of models can be used to predict locations where responses to climate change are...
Filter Total Items: 418
Intra-guild compensation regulates species richness in desert rodents: comment Intra-guild compensation regulates species richness in desert rodents: comment
No abstract available.
Authors
J.D. Nichols, J.E. Hines, J.R. Sauer, T. Boulinier, E. Cam
Variation in probability of first reproduction of Weddell seals Variation in probability of first reproduction of Weddell seals
Summary 1. For many species, when to begin reproduction is an important life-history decision that varies by individual and can have substantial implications for lifetime reproductive success and fitness. 2. We estimated age-specific probabilities of first-time breeding and modelled variation in these rates to determine age at first reproduction and understand why it varies in a...
Authors
G.L. Hadley, J.J. Rotella, R.A. Garrott, J.D. Nichols
The role of local populations within a landscape context: Defining and classifying sources and sinks The role of local populations within a landscape context: Defining and classifying sources and sinks
The interaction of local populations has been the focus of an increasing number of studies in the past 30 years. The study of source-sink dynamics has especially generated much interest. Many of the criteria used to distinguish sources and sinks incorporate the process of apparent survival (i.e., the combined probability of true survival and site fidelity) but not emigration. These...
Authors
J.P. Runge, M.C. Runge, J.D. Nichols
Assessing tiger population dynamics using photographic capture-recapture sampling Assessing tiger population dynamics using photographic capture-recapture sampling
Although wide-ranging, elusive, large carnivore species, such as the tiger, are of scientific and conservation interest, rigorous inferences about their population dynamics are scarce because of methodological problems of sampling populations at the required spatial and temporal scales. We report the application of a rigorous, noninvasive method for assessing tiger population dynamics to...
Authors
K. U. Karanth, J.D. Nichols, S. Kumar, J.E. Hines
Adaptive harvest management of North American waterfowl populations - recent successes and future prospects Adaptive harvest management of North American waterfowl populations - recent successes and future prospects
The history of North American waterfowl harvest management has been characterized by attempts to use population monitoring data to make informed harvest management decisions. Early attempts can be characterized as intuitive decision processes, and later efforts were guided increasingly by population models and associated predictions. In 1995, a formal adaptive management process was...
Authors
J.D. Nichols, M.C. Runge, Fred A. Johnson, B. Kenneth Williams
Occupancy Estimation and Modeling : Inferring Patterns and Dynamics of Species Occurrence Occupancy Estimation and Modeling : Inferring Patterns and Dynamics of Species Occurrence
This is the first book to examine the latest methods in analyzing presence/absence data surveys. Using four classes of models (single-species, single-season; single-species, multiple season; multiple-species, single-season; and multiple-species, multiple-season), the authors discuss the practical sampling situation, present a likelihood-based model enabling direct estimation of the...
Authors
D.I. MacKenzie, J.D. Nichols, J. Andrew Royle, K. H. Pollock, L.L. Bailey, J.E. Hines
Status and trends in demography of northern spotted owls, 1985-2003 Status and trends in demography of northern spotted owls, 1985-2003
We analyzed demographic data from northern spotted owls (Strix occidentalis caurina) from 14 study areas in Washington, Oregon, and California for 1985-2003. The purpose of our analyses was to provide an assessment of the status and trends of northern spotted owl populations throughout most of their geographic range. The 14 study areas made up approximately 12% of the range of the...
Authors
R.G. Anthony, E.D. Forsman, A.B. Franklin, David R. Anderson, K.P. Burnham, Gary C. White, C.J. Schwarz, J.D. Nichols, J.E. Hines, G.S. Olson, S.H. Ackers, L.S. Andrews, B.L. Biswell, P.C. Carlson, L.V. Diller, K.M. Dugger, K.E. Fehring, T.L. Fleming, R.P. Gerhardt, S.A. Gremel, R. J. Gutierrez, P.J. Happe, D.R. Herter, J.M. Higley, R.B. Horn, L.L. Irwin, P.J. Loschl, J.A. Reid, S.G. Sovern
Comparative dynamics of avian communities across edges and interiors of North American ecoregions Comparative dynamics of avian communities across edges and interiors of North American ecoregions
Aim Based on a priori hypotheses, we developed predictions about how avian communities might differ at the edges vs. interiors of ecoregions. Specifically, we predicted lower species richness and greater local turnover and extinction probabilities for regional edges. We tested these predictions using North American Breeding Bird Survey (BBS) data across nine ecoregions over a 20-year...
Authors
K.K. Karanth, J.D. Nichols, J.R. Sauer, J.E. Hines
Individual quality, survival variation and patterns of phenotypic selection on body condition and timing of nesting in birds Individual quality, survival variation and patterns of phenotypic selection on body condition and timing of nesting in birds
Questions about individual variation in “quality” and fitness are of great interest to evolutionary and population ecologists. Such variation can be investigated using either a random effects approach or an approach that relies on identifying observable traits that are themselves correlated with fitness components. We used the latter approach with data from 1,925 individual females of...
Authors
Peter Blums, James D. Nichols, James E. Hines, Mark S. Lindberg, Aivars Mednis
Improving inferences in population studies of rare species that are detected imperfectly Improving inferences in population studies of rare species that are detected imperfectly
For the vast majority of cases, it is highly unlikely that all the individuals of a population will be encountered during a study. Furthermore, it is unlikely that a constant fraction of the population is encountered over times, locations, or species to be compared. Hence, simple counts usually will not be good indices of population size. We recommend that detection probabilities (the...
Authors
Darry I. MacKenzie, James D. Nichols, N. Sutton, K. Kawanishi, Larissa Bailey
Assessing spatial coupling in complex population dynamics using mutual prediction and continuity statistics Assessing spatial coupling in complex population dynamics using mutual prediction and continuity statistics
A number of important questions in ecology involve the possibility of interactions or ?coupling? among potential components of ecological systems. The basic question of whether two components are coupled (exhibit dynamical interdependence) is relevant to investigations of movement of animals over space, population regulation, food webs and trophic interactions, and is also useful in the...
Authors
J.M. Nichols, L. Moniz, J.D. Nichols, L.M. Pecora, E. Cooch
Modern open-population capture-recapture models Modern open-population capture-recapture models
No abstract available.
Authors
J.D. Nichols