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
Using Christmas Bird Count data in analysis of population change
Book review: Restoring North America's birds: Lessons from landscape ecology. Robert A. Askins
Forest fragmentation and bird community dynamics: Inference at regional scales
Modeling avian detection probabilities as a function of habitat using double-observer point count data
Estimation of species richness and parameters reflecting community dynamics using data from ecological monitoring programs
Regional patterns in proportion of bird species detected in the North American Breeding Bird Survey
Geographic analysis of species richness and community attributes of forest birds from survey data in the mid-Atlantic integrated assessment region
Landscape associations of frog and toad species in Iowa and Wisconsin, U.S.A
Population and habitat assessment: Monitoring bird populations over large areas: Introduction
A removal model for estimating detection probabilities from point-count surveys
Relative species richness and community completeness: avian communities and urbanization in the mid-Atlantic states
Inferences about nested subsets structure when not all species are detected
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Using Christmas Bird Count data in analysis of population change
The scientific credibility of Christmas Bird Count (CBC) results depend on the development and implementation of appropriate methods of statistical analysis. The key to any successful analysis of CBC data is to begin with a careful review of how the limitations of the data are likely to influence the results of the analysis, then to choose methods of analysis that accommodate as much as possibleAuthorsJ.R. Sauer, W. A. LinkBook review: Restoring North America's birds: Lessons from landscape ecology. Robert A. Askins
No abstract available.AuthorsJohn R. SauerForest fragmentation and bird community dynamics: Inference at regional scales
With increasing fragmentation of natural areas and a dramatic reduction of forest cover in several parts of the world, quantifying the impact of such changes on species richness and community dynamics has been a subject of much concern. Here, we tested whether in more fragmented landscapes there was a lower number of area-sensitive species and higher local extinction and turnover rates, which coulAuthorsT. Boulinier, J. D. Nichols, J. E. Hines, J.R. Sauer, C.H. Flather, K. H. PollockModeling avian detection probabilities as a function of habitat using double-observer point count data
Point counts are a controversial sampling method for bird populations because the counts are not censuses, and the proportion of birds missed during counting generally is not estimated. We applied a double-observer approach to estimate detection rates of birds from point counts in Maryland, USA, and test whether detection rates differed between point counts conducted in field habitats as opposedAuthorsP.J. Heglund, J. D. Nichols, J. E. Hines, J. Sauer, J. Fallon, F. FallonEstimation of species richness and parameters reflecting community dynamics using data from ecological monitoring programs
Although many ecological monitoring programs are now in place, the use of resulting data to draw inferences about changes in biodiversity is problematic. The difficulty arises because of the inability to count all animals present in any sampled area. This inability results not only in underestimation of species richness but also in potentially misleading comparisons of species richness over timeAuthorsJ. D. Nichols, J.R. Sauer, J. E. Hines, T. Boulinier, K. H. PollockRegional patterns in proportion of bird species detected in the North American Breeding Bird Survey
Counts from the North American Breeding Bird Survey (BBS) underestimate species richness. We use capture-recapture methods to estimate species richness from BBS count data collected in 1996 and show that detection probabilities demonstrate clear regional patterns. Capture-recapture methods should be used to estimate species richness from count data, and failure to use estimation procedures for sAuthorsJ.R. Sauer, J. D. Nichols, J. E. Hines, T. Boulinier, C.H. Flather, W. L. KendallGeographic analysis of species richness and community attributes of forest birds from survey data in the mid-Atlantic integrated assessment region
Species richness of local communities is a state variable commonly used in community ecology and conservation biology. Investigation of spatial and temporal variations in richness and identification of factors associated with these variations form a basis for specifying management plans, evaluating these plans, and for testing hypotheses of theoretical interest. However, estimation of species riAuthorsEmmanuelle Cam, John R. Sauer, James D. Nichols, James E. Hines, Curtis H. FlatherLandscape associations of frog and toad species in Iowa and Wisconsin, U.S.A
Abstract has not been submittedAuthorsM. G. Knutson, J.R. Sauer, D.A. Olsen, M.J. Mossman, L.M. Hemesath, M.J. LanooPopulation and habitat assessment: Monitoring bird populations over large areas: Introduction
Monitoring provides essential information about status and change in bird populations. For Neotropical Migrant Birds (NTMBs), the North American Breeding Bird Survey (BBS) has been particularly influential in documenting regional population change and often is cited as justification for management actions. However, as with most bird surveys, the design of the BBS, and the geographic scale of theAuthorsJ.R. Sauer, R.J. CooperA removal model for estimating detection probabilities from point-count surveys
We adapted a removal model to estimate detection probability during point count surveys. The model assumes one factor influencing detection during point counts is the singing frequency of birds. This may be true for surveys recording forest songbirds when most detections are by sound. The model requires counts to be divided into several time intervals. We used time intervals of 2, 5, and 10 minAuthorsG.L. Farnsworth, K. H. Pollock, J. D. Nichols, T.R. Simons, J. E. Hines, J.R. SauerRelative species richness and community completeness: avian communities and urbanization in the mid-Atlantic states
The idea that local factors govern local richness has been dominant for years, but recent theoretical and empirical studies have stressed the influence of regional factors on local richness. Fewer species at a site could reflect not only the influence of local factors, but also a smaller regional pool. The possible dependency of local richness on the regional pool should be taken into account whAuthorsE. Cam, J. D. Nichols, J.R. Sauer, J. E. Hines, C.H. FlatherInferences about nested subsets structure when not all species are detected
Comparisons of species composition among ecological communities of different size have often provided evidence that the species in communities with lower species richness form nested subsets of the species in larger communities. In the vast majority of studies, the question of nested subsets has been addressed using information on presence-absence, where a '0' is interpreted as the absence of a gAuthorsE. Cam, J. D. Nichols, J. E. Hines, J.R. Sauer - Web Tools