John Sauer, Ph.D.
John Sauer is a Wildlife Biologist at the Eastern Ecological Science Center in Laurel, MD.
He has also worked as a Statistician with the U. S. Fish and Wildlife Service and as a Lecturer at the University of Kansas. John is an Elective Fellow of the American Ornithological Society and serves on the Board of Editors of Ecology, Ecological Monographs, and Avian Conservation and Ecology. John has been awarded the AOS Ralph W. Schreiber Conservation Award (2018) and a United States Department of Interior Distinguished Service Award (2018).
John participates in a wide variety of research projects united by the general themes of population ecology, survey design and analysis, geographic and temporal analysis of population change, analysis of count data, geographical ecology, and summary and display of large-scale surveys. Current projects include:
Analysis of population change from count data-John has participated in a series of research projects associated with analysis of population change from count data. Along with a variety of collaborators, he develops methods for analysis of counts in which counts are modeled hierarchically, as over-dispersed Poisson random variables, allowing for adjustment of both factors that influence visibility of animals and factors that actually influence population sizes. These methods are presently being implemented for the North American Breeding Bird Survey, the Christmas Bird Count, breeding waterfowl surveys in the Northeastern United States and Canada, and the Woodcock Singing-ground Survey. The methods are also used for spatial modeling and landscape level analyses, addressing questions relevant to conservation and ecology. He conducts yearly analyses of all North American Breeding Bird Survey data, and consults with researchers and managers who use the database.
Development of internet-based procedures for summary and analysis of survey data-In collaboration with other Patuxent staff, John has developed a series of web sites that allow users access to information from the North American Breeding Bird Survey and other datasets. Survey data can be accessed at several geographic scales, from individual sample units to continental summaries. A recent innovation is development of a map-based application that integrates BBS and displays BBS results at multiple geographic scale, similar to USGS mapping products associated with water resources. Custom analyses of population change can be conducted for regions, species, and time periods specified by users. Website address: http://www.mbr-pwrc.usgs.gov
Evaluating the Design of the Waterfowl Breeding Population and Habitat Survey-The Waterfowl Breeding Population and Habitat Survey (WBPHS) is a primary source of waterfowl population status and trend information for management of ducks in North America. John, along with colleagues in the United States Fish and Wildlife Service, are reviewing the current distributions of priority waterfowl species relative to the scope of the WBPHS, suggestin
Science and Products
Combining Breeding Bird Survey and Christmas Bird Count data to evaluate seasonal components of population change in Northern Bobwhite
Design and implementation of estimation-based monitoring programs for flora and fauna: A case study on the Cherokee National Forest
Seasonal components of avian population change: Joint analysis of two large-scale monitoring programs
The 1999-2003 Summary of the North American Breeding Bird Survey
Modeling and mapping abundance of American Woodcock across the Midwestern and Northeastern United States
A review of the population estimation approach of the North American landbird conservation plan
Estimating site occupancy and detection probability parameters for meso- and large mammals in a coastal eosystem
Intra-guild compensation regulates species richness in desert rodents: comment
Comparative dynamics of avian communities across edges and interiors of North American ecoregions
A hierarchical model for regional analysis of population change using Christmas Bird Count data, with application to the American Black Duck
Predicting regional abundance of rare grassland birds with a hierarchical spatial count model
Population trends of North American sea ducks as revealed by the Christmas Bird Count
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Combining Breeding Bird Survey and Christmas Bird Count data to evaluate seasonal components of population change in Northern Bobwhite
Annual surveys of wildlife populations provide information about annual rates of change in populations but provide no information about when such changes occur. However, by combining data from 2 annual surveys, conducted in different parts of the year, seasonal components of population change can be estimated. We describe a hierarchical model for simultaneous analysis of 2 continent-scale monitoriAuthorsW. A. Link, J.R. Sauer, D.K. NivenDesign and implementation of estimation-based monitoring programs for flora and fauna: A case study on the Cherokee National Forest
Science-based monitoring of biological resources is important for a greater understanding of ecological systems and for assessment of the target population using theoretic-based management approaches. When selecting variables to monitor, managers first need to carefully consider their objectives, the geographic and temporal scale at which they will operate, and the effort needed to implement theAuthorsJ.D. Klimstra, A.F. O'Connell, M.J. Pistrang, L.M. Lewis, J.A. Herrig, J.R. SauerSeasonal components of avian population change: Joint analysis of two large-scale monitoring programs
We present a combined analysis of data from two large-scale surveys of bird populations. The North American Breeding Bird Survey is conducted each summer; the Christmas Bird Count is conducted in early winter. The temporal staggering of these surveys allows investigation of seasonal components of population change, which we illustrate with an examination of the effects of severe winters on the CarAuthorsW. A. Link, J.R. SauerThe 1999-2003 Summary of the North American Breeding Bird Survey
Data from the North American Breeding Bird Survey were used to estimate continental and regional changes in bird populations for the 5-yr period 1999-2003 and the 2-yr period 2002-2003. These short-term changes were placed in the context of population trends estimated over the 1966-2003 interval. During 1999-2003, 41% of all species exhibited positive trends over the entire survey area, while 64AuthorsK.L. Pardieck, J.R. SauerModeling and mapping abundance of American Woodcock across the Midwestern and Northeastern United States
We used an over-dispersed Poisson regression with fixed and random effects, fitted by Markov chain Monte Carlo methods, to model population spatial patterns of relative abundance of American woodcock (Scolopax minor) across its breeding range in the United States. We predicted North American woodcock Singing Ground Survey counts with a log-linear function of explanatory variables describing habitaAuthorsW.E. Thogmartin, J.R. Sauer, M. G. KnutsonA review of the population estimation approach of the North American landbird conservation plan
As part of their development of a continental plan for monitoring landbirds (Rich et al. 2004), Partners in Flight (PIF) applied a new method to make preliminary estimates of population size for all 448 species of landbirds present in the continental United States and Canada (Table 1). Estimation of the global population size of North American landbirds was intended to (1) identify the degree of vAuthorsWayne E. Thogmartin, Frank P. Howe, Frances C. James, Douglas H. Johnson, Eric T. Reed, John R. Sauer, Frank R. ThompsonEstimating site occupancy and detection probability parameters for meso- and large mammals in a coastal eosystem
Large-scale, multispecies monitoring programs are widely used to assess changes in wildlife populations but they often assume constant detectability when documenting species occurrence. This assumption is rarely met in practice because animal populations vary across time and space. As a result, detectability of a species can be influenced by a number of physical, biological, or anthropogenic factoAuthorsAllan F. O'Connell, Neil W. Talancy, Larissa L. Bailey, John R. Sauer, Robert Cook, Andrew T. GilbertIntra-guild compensation regulates species richness in desert rodents: comment
No abstract available.AuthorsJ. D. Nichols, J. E. Hines, J.R. Sauer, T. Boulinier, E. CamComparative 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 time perioAuthorsK.K. Karanth, J. D. Nichols, J.R. Sauer, J. E. HinesA hierarchical model for regional analysis of population change using Christmas Bird Count data, with application to the American Black Duck
Analysis of Christmas Bird Count (CBC) data is complicated by the need to account for variation in effort on counts and to provide summaries over large geographic regions. We describe a hierarchical model for analysis of population change using CBC data that addresses these needs. The effect of effort is modeled parametrically, with parameter values varying among strata as identically distributeAuthorsW. A. Link, J.R. Sauer, D.K. NivenPredicting regional abundance of rare grassland birds with a hierarchical spatial count model
Grassland birds are among the most imperiled groups of birds in North America. Unfortunately, little is known about the location of regional concentrations of these birds, thus regional or statewide conservation efforts may be inappropriately applied, reducing their effectiveness. We identified environmental covariates associated with the abundance of five grassland birds in the upper midwesternAuthorsW.E. Thogmartin, M. G. Knutson, J.R. SauerPopulation trends of North American sea ducks as revealed by the Christmas Bird Count
Relative to other waterfowl, sea ducks are not well understood, yet evidence from a variety of analyses suggests that as many as 10 of the 15 species of North American sea ducks may be declining in population. However, because of the difficulty of conducting surveys of breeding populations and the lack of range-wide winter surveys, few data are available to assess the population trends of sea ducAuthorsD.K. Niven, J.R. Sauer, G.S. Butcher - Web Tools