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
Modeled distribution shifts of North American birds over four decades based on suitable climate alone do not predict observed shifts
Maryland birds through time series— New!
American Woodcock singing-ground survey: Comparison of four models for trend in population size
Assessing the efficacy of protected and multiple-use lands for bird conservation in the U.S.
Model selection for the North American Breeding Bird Survey
Decline of the North American avifauna
Consistency counts: Modeling the effects of a change in protocol on Breeding Bird Survey counts
Allowable take of black vultures in the eastern United States
Multidirectional abundance shifts among North American birds and the relative influence of multifaceted climate factors
On the reliability of N‐mixture models for count data
On the robustness of N‐mixture models
Combined analysis of roadside and off-road breeding bird survey data to assess population change in Alaska
Evaluating the Design of the Waterfowl Breeding Population and Habitat Survey
Population Change and Abundance of Black Ducks and Mallards in Eastern North America
Implementing Cross Validation Approaches for Model Selection and Evaluating Goodness of Fit in Complex Hierarchical Models
Design and Analysis of Surveys for Estimation of Temporal and Spatial Change in Animal Populations
SERAP: Assessment of Climate and Land Use Change Impacts on Terrestrial Species
The North American Breeding Bird Survey, Analysis Results 1966 - 2021
Phenology effects in the North American Breeding Bird Survey
The North American Breeding Bird Survey, Analysis Results 1966 - 2019
The North American Breeding Bird Survey, Analysis Results 1966 - 2018
The North American Breeding Bird Survey, Analysis Results 1966 - 2017
North American Breeding Bird Survey Results and Analysis
This website provides visualizations of population change for North American birds using data from the North American Breeding Bird Survey (BBS). The BBS is analyzed for a "core" area (contiguous United States and southern Canada, results available from 1966-present), and for an "expanded" survey area (including portions of Alaska and northern Canada with results from 1993-present).
Science and Products
- Publications
Filter Total Items: 216
Modeled distribution shifts of North American birds over four decades based on suitable climate alone do not predict observed shifts
As climate change alters the global environment, it is critical to understand the relationship between shifting climate suitability and species distributions. Key questions include whether observed changes in population abundance are aligned with the velocity and direction of shifts predicted by climate suitability models and if the responses are consistent among species with similar ecological trAuthorsQiongyu Huang, Brooke L. Bateman, Nicole Michel, Anna M. Pidgeon, Voelker C. Radeloff, Patrician Heglund, Andrew J. Allstadt, Jesse Wong, John R. SauerMaryland birds through time series— New!
No abstract available.AuthorsDavid Ziolkowski, John R. SauerAmerican Woodcock singing-ground survey: Comparison of four models for trend in population size
Wildlife biologists monitor the status and trends of American woodcock Scolopax minor populations in the eastern and central United States and Canada via a singing-ground survey, conducted just after sunset along roadsides in spring. Annual analyses of the survey produce estimates of trend and annual indexes of abundance for 25 states and provinces, management regions, and survey-wide. In recent yAuthorsJohn R. Sauer, William Link, Mark E Seamans, Rebecca D. RauAssessing the efficacy of protected and multiple-use lands for bird conservation in the U.S.
Setting land aside has long been a primary approach for protecting biodiversity; however, the efficacy of this approach has been questioned. We examined whether protecting lands positively influences bird species in the U.S., and thus overall biodiversity. We used the North American Breeding Bird Survey and Protected Areas Database of the U.S. to assess effects of protected and multiple-use landsAuthorsL. Lynnette Dornak, Jocelyn L. Aycrigg, John R. Sauer, Courtney J. ConwayModel selection for the North American Breeding Bird Survey
The North American Breeding Bird Survey (BBS) provides data that can be used in complex, multiscale analyses of population change, while controlling for scale‐specific nuisance factors. Many alternative models can be fit to the data, but most model selection procedures are not appropriate for hierarchical models. Leave‐one‐out cross‐validation (LOOCV), in which relative model fit is assessed by omAuthorsWilliam A. Link, John R. Sauer, Daniel K NivenDecline of the North American avifauna
Species extinctions have defined the global biodiversity crisis, but extinction begins with loss in abundance of organisms that can result in extreme compositional and functional changes of ecosystems. Using multiple and independent monitoring networks, we report major population losses across much of the North American avifauna, including in once common species and from nearly every biome. IntegrAuthorsJohn R. Sauer, Kenneth V. Rosenberg, Adriaan M. Dokter, Peter J. Blancher, Adam C. Smith, Paul A. Smith, Jessica C. Stanton, Arvind O. Panjabi, Laura Helft, Michael J. Parr, Peter P. MarraConsistency counts: Modeling the effects of a change in protocol on Breeding Bird Survey counts
Analysis of North American Breeding Bird Survey (BBS) data requires controls for factors that influence detectability of birds along survey routes. Identifying factors that influence the counting process and incorporating them into analyses is a primary means of limiting bias in estimates of population change. Twedt (2015) implemented an alternative counting protocol on operational and non-randAuthorsJohn R. Sauer, William A. Link, David Ziolkowski, Keith L. Pardieck, Daniel J. TwedtAllowable take of black vultures in the eastern United States
Black vultures (Coragyps atratus) have been increasing in density and expanding their range in the eastern United States since at least the 1960s. In many areas, their densities have increased to the level where they are causing damage to property and livestock and the number of requests for allowable take permits has increased throughout these areas. The United States Fish and Wildlife Service (UAuthorsGuthrie S. Zimmerman, Brian A. Millsap, Michael L. Avery, John R. Sauer, Michael C. Runge, Kenneth D. RichkusMultidirectional abundance shifts among North American birds and the relative influence of multifaceted climate factors
Shifts in species distributions are major fingerprint of climate change. Examining changes in species abundance structures at a continental scale enables robust evaluation of climate change influences, but few studies have conducted these evaluations due to limited data and methodological constraints. In this study, we estimate temporal changes in abundance from North American Breeding Bird SurveyAuthorsQiongyu Huang, John R. Sauer, Ralph O. DubayahOn the reliability of N‐mixture models for count data
N‐mixture models describe count data replicated in time and across sites in terms of abundance N and detectability p. They are popular because they allow inference about N while controlling for factors that influence p without the need for marking animals. Using a capture–recapture perspective, we show that the loss of information that results from not marking animals is critical, making reliableAuthorsRichard J. Barker, Matthew J. Schofield, William A. Link, John R. SauerOn the robustness of N‐mixture models
N‐mixture models provide an appealing alternative to mark–recapture models, in that they allow for estimation of detection probability and population size from count data, without requiring that individual animals be identified. There is, however, a cost to using the N‐mixture models: inference is very sensitive to the model's assumptions. We consider the effects of three violations of assumptionsAuthorsWilliam A. Link, Matthew R. Schofield, Richard J. Barker, John R. SauerCombined analysis of roadside and off-road breeding bird survey data to assess population change in Alaska
Management interest in North American birds has increasingly focused on species that breed in Alaska, USA, and Canada, where habitats are changing rapidly in response to climatic and anthropogenic factors. We used a series of hierarchical models to estimate rates of population change in 2 forested Bird Conservation Regions (BCRs) in Alaska based on data from the roadside North American Breeding BiAuthorsColleen M. Handel, John R. Sauer - Science
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. The survey has not been reviewed in several decades, and since the last review new analysis approaches and information needs have created a need to reassess the design, scope of inference, and analysis of the survey to...Population Change and Abundance of Black Ducks and Mallards in Eastern North America
The boreal forest in the northeastern United States and eastern Canada contains most of the breeding range of the American black duck (Anas rubripes). We collaborate with scientists from the U. S. Fish and Wildlife Service to design and analyze waterfowl surveys in this large and often inaccessible area.Implementing Cross Validation Approaches for Model Selection and Evaluating Goodness of Fit in Complex Hierarchical Models
It is (relatively) easy to construct complex hierarchical models for analysis of the North American Breeding Bird Survey (BBS), but deciding which model best describes population change is difficult. We are developing methods for model selection for BBS and other important survey data sets, and using them to refine our estimates of population change from this important survey.Design and Analysis of Surveys for Estimation of Temporal and Spatial Change in Animal Populations
Designing and analyzing large-scale animal surveys is an important focus of our research. Although we conduct research into analysis methods for many surveys, the primary focus of this project is to conduct analyses and develop web-based summaries of data from the North American Breeding Bird Survey (BBS).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 most lik - Data
The North American Breeding Bird Survey, Analysis Results 1966 - 2021
This data product consists of a database of population change and abundance estimates for North American birds, estimated from North American Breeding Bird Survey (BBS) data. Data are presented for 548 species of birds in 4 spreadsheets containing trend estimates and annual indices for 2 time periods. Estimates are derived for each species using the 1 of 4 alternative models, and a cross-validatioPhenology effects in the North American Breeding Bird Survey
This data product provides summary information, by species, of changes in relative visibility of birds (phenology effects) through the April - July time period in which the North American Breeding Bird Survey (BBS) is conducted. Data are presented for 408 species of birds. Seasonal phenology effects are presented for selected latitudes and years, documenting changes in visibility and a variety ofThe North American Breeding Bird Survey, Analysis Results 1966 - 2019
This data product consists of a database of population change and abundance estimates for North American birds, estimated from North American Breeding Bird Survey (BBS) data. Data are presented for 548 species of birds in 4 spreadsheets containing trend estimates and annual indices for 2 time periods. Estimates are derived for each species using the 1 of 4 alternative models, and a cross-validatioThe North American Breeding Bird Survey, Analysis Results 1966 - 2018
This data product consists of a database of population change and abundance estimates for North American birds, estimated from North American Breeding Bird Survey (BBS) data. Data are presented for 548 species of birds in 4 spreadsheets containing trend estimates and annual indices for 2 time periods. Estimates are derived for each species using the 1 of 4 alternative models, and a cross-validatioThe North American Breeding Bird Survey, Analysis Results 1966 - 2017
This data product consists of a database of population change and relative abundance estimates for North American birds, estimated from North American Breeding Bird Survey (BBS) data. Data are presented in 6 separate spreadsheets for 2 methods of trend summary and 3 time periods for 548 species of birds. Metadata for the BBS data used to produce these estimates is available from a USGS ftp site (f - Web Tools
North American Breeding Bird Survey Results and Analysis
This website provides visualizations of population change for North American birds using data from the North American Breeding Bird Survey (BBS). The BBS is analyzed for a "core" area (contiguous United States and southern Canada, results available from 1966-present), and for an "expanded" survey area (including portions of Alaska and northern Canada with results from 1993-present).