James Nichols, Ph.D.
Dr. Jim Nichols conducts research on animal population dynamics and management
Recent Accomplishments
Education
- B.S. Wake Forest University, Biology, 1971
- M.S. Louisiana State University, Wildlife Management, 1973
- Ph.D. Michigan State University, Wildlife Ecology, 1976
Professional Studies/Experience
- Adaptive management and assessment of habitat changes on migratory birds
- Development of models of mallard population dynamics for adaptive harvest management
- Development of methods to estimate parameters associated with animal population dynamics
- Statistical methods for species richness estimation
- Technical Assistance -Tiger Monitoring and Population Research
- Development of methods for estimating patch occupancy and patch-dynamic parameters from detection-nondetection survey data
- Development of methods to estimate species richness and community-dynamic parameters from species list data
Mentorship/Outreach
Professional societies/affiliations/committees/editorial boardsScientific/Oral Presentations, Abstracts
Honors, awards, recognition, elected offices
- 2005 - U.S. Presidential Rank Award (Meritorious Senior Professional)
- 2004 - U.S. Geological Survey Meritorious Service Award
- 2004 - IFAS Scholar Award, University of Florida
- 1998 - Promoted to Senior Scientist, U.S. Geological Survey
- 1991 - The George W. Snedecor Award of the American Statistical Association
- 1991 - The Wildlife Society's Wildlife Publication Award for Monograph
- 1984 - Southeastern Section of the Wildlife Society, Outstanding Publication Award
Scientific/Oral Presentations, Abstracts
Science and Products
Filter Total Items: 418
Double-observer approach to estimating egg mass abundance of vernal pool breeding amphibians Double-observer approach to estimating egg mass abundance of vernal pool breeding amphibians
Interest in seasonally flooded pools, and the status of associated amphibian populations, has initiated programs in the northeastern United States to document and monitor these habitats. Counting egg masses is an effective way to determine the population size of pool-breeding amphibians, such as wood frogs (Rana sylvatica) and spotted salamanders (Ambystoma maculatum). However, bias is...
Authors
Evan H. Campbell Grant, Robin E. Jung, James D. Nichols, James E. Hines
Modelling occurrence and abundance of species when detection is imperfect Modelling occurrence and abundance of species when detection is imperfect
Relationships between species abundance and occupancy are of considerable interest in metapopulation biology and in macroecology. Such relationships may be described concisely using probability models that characterize variation in abundance of a species. However, estimation of the parameters of these models in most ecological problems is impaired by imperfect detection. When organisms...
Authors
J. Andrew Royle, James D. Nichols, Marc Kery
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
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
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
Modern open-population capture-recapture models Modern open-population capture-recapture models
No abstract available.
Authors
J.D. Nichols
Statistical approaches to the analysis of point count data: A little extra information can go a long way Statistical approaches to the analysis of point count data: A little extra information can go a long way
Point counts are a standard sampling procedure for many bird species, but lingering concerns still exist about the quality of information produced from the method. It is well known that variation in observer ability and environmental conditions can influence the detection probability of birds in point counts, but many biologists have been reluctant to abandon point counts in favor of...
Authors
G.L. Farnsworth, J.D. Nichols, J.R. Sauer, S.G. Fancy, K. H. Pollock, S.A. Shriner, T.R. Simons
Estimating the number of animals in wildlife populations Estimating the number of animals in wildlife populations
INTRODUCTION In 1938, Howard M. Wight devoted 9 pages, which was an entire chapter in the first wildlife management techniques manual, to what he termed 'census' methods. As books and chapters such as this attest, the volume of literature on this subject has grown tremendously. Abundance estimation remains an active area of biometrical research, as reflected in the many differences...
Authors
R.A. Lancia, W. L. Kendall, K. H. Pollock, J.D. Nichols
Abundance estimation and conservation biology Abundance estimation and conservation biology
Abundance is the state variable of interest in most population–level ecological research and in most programs involving management and conservation of animal populations. Abundance is the single parameter of interest in capture–recapture models for closed populations (e.g., Darroch, 1958; Otis et al., 1978; Chao, 2001). The initial capture–recapture models developed for partially...
Authors
J.D. Nichols, D.I. MacKenzie
Occupancy as a surrogate for abundance estimation Occupancy as a surrogate for abundance estimation
In many monitoring programmes it may be prohibitively expensive to estimate the actual abundance of a bird species in a defined area, particularly at large spatial scales, or where birds occur at very low densities. Often it may be appropriate to consider the proportion of area occupied by the species as an alternative state variable. However, as with abundance estimation, issues of
Authors
D.I. MacKenzie, J.D. Nichols
Estimation of sex-specific survival from capture-recapture data when sex is not always known Estimation of sex-specific survival from capture-recapture data when sex is not always known
Many animals lack obvious sexual dimorphism, making assignment of sex difficult even for observed or captured animals. For many such species it is possible to assign sex with certainty only at some occasions; for example, when they exhibit certain types of behavior. A common approach to handling this situation in capture-recapture studies has been to group capture histories into those of...
Authors
J.D. Nichols, W. L. Kendall, J.E. Hines, J. A. Spendelow
Investigating species co-occurrence patterns when species are detected imperfectly Investigating species co-occurrence patterns when species are detected imperfectly
1. Over the last 30 years there has been a great deal of interest in investigating patterns of species co-occurrence across a number of locations, which has led to the development of numerous methods to determine whether there is evidence that a particular pattern may not have occurred by random chance. 2. A key aspect that seems to have been largely overlooked is the possibility that...
Authors
D.I. MacKenzie, L.L. Bailey, J.D. Nichols
Science and Products
Filter Total Items: 418
Double-observer approach to estimating egg mass abundance of vernal pool breeding amphibians Double-observer approach to estimating egg mass abundance of vernal pool breeding amphibians
Interest in seasonally flooded pools, and the status of associated amphibian populations, has initiated programs in the northeastern United States to document and monitor these habitats. Counting egg masses is an effective way to determine the population size of pool-breeding amphibians, such as wood frogs (Rana sylvatica) and spotted salamanders (Ambystoma maculatum). However, bias is...
Authors
Evan H. Campbell Grant, Robin E. Jung, James D. Nichols, James E. Hines
Modelling occurrence and abundance of species when detection is imperfect Modelling occurrence and abundance of species when detection is imperfect
Relationships between species abundance and occupancy are of considerable interest in metapopulation biology and in macroecology. Such relationships may be described concisely using probability models that characterize variation in abundance of a species. However, estimation of the parameters of these models in most ecological problems is impaired by imperfect detection. When organisms...
Authors
J. Andrew Royle, James D. Nichols, Marc Kery
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
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
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
Modern open-population capture-recapture models Modern open-population capture-recapture models
No abstract available.
Authors
J.D. Nichols
Statistical approaches to the analysis of point count data: A little extra information can go a long way Statistical approaches to the analysis of point count data: A little extra information can go a long way
Point counts are a standard sampling procedure for many bird species, but lingering concerns still exist about the quality of information produced from the method. It is well known that variation in observer ability and environmental conditions can influence the detection probability of birds in point counts, but many biologists have been reluctant to abandon point counts in favor of...
Authors
G.L. Farnsworth, J.D. Nichols, J.R. Sauer, S.G. Fancy, K. H. Pollock, S.A. Shriner, T.R. Simons
Estimating the number of animals in wildlife populations Estimating the number of animals in wildlife populations
INTRODUCTION In 1938, Howard M. Wight devoted 9 pages, which was an entire chapter in the first wildlife management techniques manual, to what he termed 'census' methods. As books and chapters such as this attest, the volume of literature on this subject has grown tremendously. Abundance estimation remains an active area of biometrical research, as reflected in the many differences...
Authors
R.A. Lancia, W. L. Kendall, K. H. Pollock, J.D. Nichols
Abundance estimation and conservation biology Abundance estimation and conservation biology
Abundance is the state variable of interest in most population–level ecological research and in most programs involving management and conservation of animal populations. Abundance is the single parameter of interest in capture–recapture models for closed populations (e.g., Darroch, 1958; Otis et al., 1978; Chao, 2001). The initial capture–recapture models developed for partially...
Authors
J.D. Nichols, D.I. MacKenzie
Occupancy as a surrogate for abundance estimation Occupancy as a surrogate for abundance estimation
In many monitoring programmes it may be prohibitively expensive to estimate the actual abundance of a bird species in a defined area, particularly at large spatial scales, or where birds occur at very low densities. Often it may be appropriate to consider the proportion of area occupied by the species as an alternative state variable. However, as with abundance estimation, issues of
Authors
D.I. MacKenzie, J.D. Nichols
Estimation of sex-specific survival from capture-recapture data when sex is not always known Estimation of sex-specific survival from capture-recapture data when sex is not always known
Many animals lack obvious sexual dimorphism, making assignment of sex difficult even for observed or captured animals. For many such species it is possible to assign sex with certainty only at some occasions; for example, when they exhibit certain types of behavior. A common approach to handling this situation in capture-recapture studies has been to group capture histories into those of...
Authors
J.D. Nichols, W. L. Kendall, J.E. Hines, J. A. Spendelow
Investigating species co-occurrence patterns when species are detected imperfectly Investigating species co-occurrence patterns when species are detected imperfectly
1. Over the last 30 years there has been a great deal of interest in investigating patterns of species co-occurrence across a number of locations, which has led to the development of numerous methods to determine whether there is evidence that a particular pattern may not have occurred by random chance. 2. A key aspect that seems to have been largely overlooked is the possibility that...
Authors
D.I. MacKenzie, L.L. Bailey, J.D. Nichols