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John R. Sauer - One of the best experts on this subject based on the ideXlab platform.
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Model selection for the North American Breeding Bird Survey
Ecological applications : a publication of the Ecological Society of America, 2020Co-Authors: William A Link, John R. Sauer, Daniel K. NivenAbstract: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 omitting an observation and assessing the prediction of a model fit using the remainder of the data, provides a reasonable approach for assessing models, but is time consuming and not feasible to apply for all observations in large data sets. We report the first large-scale formal model selection for BBS data, applying LOOCV to stratified random samples of observations from BBS data. Our results are for 548 species of North American Birds, comparing the fit of four alternative models that differ in year effect structures and in descriptions of extra-Poisson overdispersion. We use a hierarchical model among species to evaluate posterior probabilities that models are best for individual species. Models in which differences in year effects are conditionally independent (D models) were generally favored over models in which year effects are modeled by a slope parameter and a random year effect (S models), and models in which extra-Poisson overdispersion effects are independent and t-distributed (H models) tended to be favored over models where overdispersion was independent and normally distributed. Our conclusions lead us to recommend a change from the conventional S model to D and H models for the vast majority of species (544/548). Comparison of estimated population trends based on the favored model relative to the S model currently used for BBS summaries indicates no consistent differences in estimated trends. Of the 18 species that showed large differences in estimated trends between models, estimated trends from the default S model were more extreme, reflecting the influence of the slope parameter in that model for species that are undergoing large population changes. WAIC, a computationally simpler alternative to LOOCV, does not appear to be a reliable alternative to LOOCV.
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Consistency counts: Modeling the effects of a change in protocol on Breeding Bird Survey counts
The Condor, 2019Co-Authors: John R. Sauer, William A Link, Keith L. Pardieck, David J. Ziolkowski, Daniel J. TwedtAbstract: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 nonrandom BBS Survey routes in the southeastern United States. Observers on selected routes employed a time–distance protocol in which they recorded Birds in 1–min intervals and in 2 distance categories. We hypothesized that processing and recording observations using this time–distance protocol could cause observers to count fewer Birds relative to observers using the standard protocol. We used a hierarchical log–linear model with a categorical covariate associated with protocol (standard vs. time–distance) to assess whether use of the time–distance protocol had a measurable effect on counting Birds along BBS routes. We applied this model to BBS data from portions of 8 states in which the time–distance protocol was implemented and estimated a protocol effect for 167 Bird species. We documented a significant overall effect of the time–distance protocol on observers'counts of Birds. On average, the effect of the time–distance protocol was a 10% decline in counted Birds; 80% of species had lower counts when the time–distance protocol was used on a Survey route. However, because the time–distance protocol was only used on a small portion of the operational BBS routes and for a limited time, including the covariate for the time–distance protocol data had insignificant effects on analysis of population change. Although the covariate controlled for the effects of the time–distance protocol in BBS data, the results emphasize the importance of standardization as well as a need to track and, if necessary, control in analyses for changes in counting procedures along BBS routes.
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Expanding the North American Breeding Bird Survey Analysis to Include Additional Species and Regions
Journal of Fish and Wildlife Management, 2017Co-Authors: John R. Sauer, Keith L. Pardieck, David J. Ziolkowski, Daniel K. Niven, William A LinkAbstract:Abstract The North American Breeding Bird Survey (BBS) contains data for >700 Bird species, but analyses often focus on a core group of ∼420 species. We analyzed data for 122 species of North Ameri...
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Combined analysis of roadside and off-road Breeding Bird Survey data to assess population change in Alaska
The Condor, 2017Co-Authors: Colleen M. Handel, John R. SauerAbstract:ABSTRACT 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 Bird Survey (BBS) and the Alaska LandBird Monitoring Survey, which samples off-road areas on public resource lands. We estimated long-term (1993–2015) population trends for 84 Bird species from the BBS and short-term (2003–2015) trends for 31 species from both Surveys. Among the 84 species with long-term estimates, 11 had positive trends and 17 had negative trends in 1 or both BCRs; negative trends were primarily found among aerial insectivores and wetland-associated species, confirming range-wide negative continental trends for many of these Birds. Three species with negative trends in the contiguous Unit...
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The first 50 years of the North American Breeding Bird Survey
The Condor, 2017Co-Authors: John R. Sauer, Keith L. Pardieck, David J. Ziolkowski, Adam C. Smith, Marie-anne R. Hudson, Vicente Rodriguez, Humberto Berlanga, Daniel K. Niven, William A LinkAbstract:ABSTRACT The vision of Chandler (Chan) S. Robbins for a continental-scale omnibus Survey of Breeding Birds led to the development of the North American Breeding Bird Survey (BBS). Chan was uniquely suited to develop the BBS. His position as a government scientist had given him experience with designing and implementing continental-scale Surveys, his research background made him an effective advocate of the need for a Survey to monitor pesticide effects on Birds, and his prominence in the Birding community gave him connections to infrastructure—a network of qualified volunteer Birders who could conduct roadside Surveys with standardized point counts. Having started in the eastern United States and the Atlantic provinces of Canada in 1966, the BBS now provides population change information for ∼546 species in the continental United States and Canada, and recently initiated routes in Mexico promise to greatly expand the areas and species covered by the Survey. Although Survey protocols have remained unchange...
William A Link - One of the best experts on this subject based on the ideXlab platform.
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Model selection for the North American Breeding Bird Survey
Ecological applications : a publication of the Ecological Society of America, 2020Co-Authors: William A Link, John R. Sauer, Daniel K. NivenAbstract: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 omitting an observation and assessing the prediction of a model fit using the remainder of the data, provides a reasonable approach for assessing models, but is time consuming and not feasible to apply for all observations in large data sets. We report the first large-scale formal model selection for BBS data, applying LOOCV to stratified random samples of observations from BBS data. Our results are for 548 species of North American Birds, comparing the fit of four alternative models that differ in year effect structures and in descriptions of extra-Poisson overdispersion. We use a hierarchical model among species to evaluate posterior probabilities that models are best for individual species. Models in which differences in year effects are conditionally independent (D models) were generally favored over models in which year effects are modeled by a slope parameter and a random year effect (S models), and models in which extra-Poisson overdispersion effects are independent and t-distributed (H models) tended to be favored over models where overdispersion was independent and normally distributed. Our conclusions lead us to recommend a change from the conventional S model to D and H models for the vast majority of species (544/548). Comparison of estimated population trends based on the favored model relative to the S model currently used for BBS summaries indicates no consistent differences in estimated trends. Of the 18 species that showed large differences in estimated trends between models, estimated trends from the default S model were more extreme, reflecting the influence of the slope parameter in that model for species that are undergoing large population changes. WAIC, a computationally simpler alternative to LOOCV, does not appear to be a reliable alternative to LOOCV.
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Consistency counts: Modeling the effects of a change in protocol on Breeding Bird Survey counts
The Condor, 2019Co-Authors: John R. Sauer, William A Link, Keith L. Pardieck, David J. Ziolkowski, Daniel J. TwedtAbstract: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 nonrandom BBS Survey routes in the southeastern United States. Observers on selected routes employed a time–distance protocol in which they recorded Birds in 1–min intervals and in 2 distance categories. We hypothesized that processing and recording observations using this time–distance protocol could cause observers to count fewer Birds relative to observers using the standard protocol. We used a hierarchical log–linear model with a categorical covariate associated with protocol (standard vs. time–distance) to assess whether use of the time–distance protocol had a measurable effect on counting Birds along BBS routes. We applied this model to BBS data from portions of 8 states in which the time–distance protocol was implemented and estimated a protocol effect for 167 Bird species. We documented a significant overall effect of the time–distance protocol on observers'counts of Birds. On average, the effect of the time–distance protocol was a 10% decline in counted Birds; 80% of species had lower counts when the time–distance protocol was used on a Survey route. However, because the time–distance protocol was only used on a small portion of the operational BBS routes and for a limited time, including the covariate for the time–distance protocol data had insignificant effects on analysis of population change. Although the covariate controlled for the effects of the time–distance protocol in BBS data, the results emphasize the importance of standardization as well as a need to track and, if necessary, control in analyses for changes in counting procedures along BBS routes.
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Expanding the North American Breeding Bird Survey Analysis to Include Additional Species and Regions
Journal of Fish and Wildlife Management, 2017Co-Authors: John R. Sauer, Keith L. Pardieck, David J. Ziolkowski, Daniel K. Niven, William A LinkAbstract:Abstract The North American Breeding Bird Survey (BBS) contains data for >700 Bird species, but analyses often focus on a core group of ∼420 species. We analyzed data for 122 species of North Ameri...
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The first 50 years of the North American Breeding Bird Survey
The Condor, 2017Co-Authors: John R. Sauer, Keith L. Pardieck, David J. Ziolkowski, Adam C. Smith, Marie-anne R. Hudson, Vicente Rodriguez, Humberto Berlanga, Daniel K. Niven, William A LinkAbstract:ABSTRACT The vision of Chandler (Chan) S. Robbins for a continental-scale omnibus Survey of Breeding Birds led to the development of the North American Breeding Bird Survey (BBS). Chan was uniquely suited to develop the BBS. His position as a government scientist had given him experience with designing and implementing continental-scale Surveys, his research background made him an effective advocate of the need for a Survey to monitor pesticide effects on Birds, and his prominence in the Birding community gave him connections to infrastructure—a network of qualified volunteer Birders who could conduct roadside Surveys with standardized point counts. Having started in the eastern United States and the Atlantic provinces of Canada in 1966, the BBS now provides population change information for ∼546 species in the continental United States and Canada, and recently initiated routes in Mexico promise to greatly expand the areas and species covered by the Survey. Although Survey protocols have remained unchange...
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Model selection for the North American Breeding Bird Survey: A comparison of methods
The Condor, 2017Co-Authors: William A Link, John R. Sauer, Daniel K. NivenAbstract:ABSTRACT The North American Breeding Bird Survey (BBS) provides data for >420 Bird species at multiple geographic scales over 5 decades. Modern computational methods have facilitated the fitting of complex hierarchical models to these data. It is easy to propose and fit new models, but little attention has been given to model selection. Here, we discuss and illustrate model selection using leave-one-out cross validation, and the Bayesian Predictive Information Criterion (BPIC). Cross-validation is enormously computationally intensive; we thus evaluate the performance of the Watanabe-Akaike Information Criterion (WAIC) as a computationally efficient approximation to the BPIC. Our evaluation is based on analyses of 4 models as applied to 20 species covered by the BBS. Model selection based on BPIC provided no strong evidence of one model being consistently superior to the others; for 14/20 species, none of the models emerged as superior. For the remaining 6 species, a first-difference model of population tr...
Frederic Jiguet - One of the best experts on this subject based on the ideXlab platform.
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method learning caused a first time observer effect in a newly started Breeding Bird Survey
Bird Study, 2009Co-Authors: Frederic JiguetAbstract:Capsule A first‐time observer effect in the new French Breeding Bird Survey (BBS) was found to result from new observers learning how to use the point count method on randomly selected sites. Aims To estimate the first‐year effect in a newly started BBS, to look for correlates and test for a temporal trend in learning. Methods Trends of 105 species were estimated using data from 2001–2007 obtained by 1100 observers conducting point counts over 1535 randomly selected squares. I estimated the average increase in detected numbers between the first and all subsequent years of Survey at a site. Results Observers counted 4.3% more Birds in subsequent years than during the initial year of Survey. This first‐year effect decreased from 2001 to 2007 (by an average of 2% per year). It was not related to most variables known to influence species detection probability. Only species with songs of lower sound frequencies (ranging from 0.5 to 8 kHz here) displayed a greater increase in locally detected numbers. Conclusio...
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Method learning caused a first‐time observer effect in a newly started Breeding Bird Survey
Bird Study, 2009Co-Authors: Frederic JiguetAbstract:Capsule A first‐time observer effect in the new French Breeding Bird Survey (BBS) was found to result from new observers learning how to use the point count method on randomly selected sites. Aims To estimate the first‐year effect in a newly started BBS, to look for correlates and test for a temporal trend in learning. Methods Trends of 105 species were estimated using data from 2001–2007 obtained by 1100 observers conducting point counts over 1535 randomly selected squares. I estimated the average increase in detected numbers between the first and all subsequent years of Survey at a site. Results Observers counted 4.3% more Birds in subsequent years than during the initial year of Survey. This first‐year effect decreased from 2001 to 2007 (by an average of 2% per year). It was not related to most variables known to influence species detection probability. Only species with songs of lower sound frequencies (ranging from 0.5 to 8 kHz here) displayed a greater increase in locally detected numbers. Conclusio...
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Method learning caused a first-time observer effect in a newly started Breeding Bird Survey - Un biais observateur dû à l'apprentissage pendant les premières années de suivi des oiseaux nicheurs
Bird Study, 2009Co-Authors: Frederic JiguetAbstract:Capsule A first-time observer effect in the new French Breeding Bird Survey (BBS) was found to result from new observers learning how to use the point count method on randomly selected sites. Aims To estimate the first-year effect in a newly started BBS, to look for correlates and test for a temporal trend in learning. Methods Trends of 105 species were estimated using data from 2001-2007 obtained by 1100 observers conducting point counts over 1535 randomly selected squares. I estimated the average increase in detected numbers between the first and all subsequent years of Survey at a site. Results Observers counted 4.3% more Birds in subsequent years than during the initial year of Survey. This first-year effect decreased from 2001 to 2007 (by an average of 2% per year). It was not related to most variables known to influence species detection probability. Only species with songs of lower sound frequencies (ranging from 0.5 to 8 kHz here) displayed a greater increase in locally detected numbers. Conclusion The detected first-year effect was the result of method learning by new observers who had not previously conducted point counts or visited randomly selected sites. The learning effect was larger for species with songs of lower sound frequency which are harder to hear during the dawn chorus. ---------------------------------------------------------------Résumé : pour la première fois l'effet observateur dans la nouvelle enquête de relevé d'oiseaux nicheurs (BBS) français a été trouvé et résultait des nouveaux observateurs qui apprennent à utiliser la méthode de point de comptage sur des sites choisis au hasard. Objectifs : estimer l'effet première année dans un BBS nouvellement ouvert, pour trouver des corrélations et pour tester une temporelle tendance lors de l'apprentissage. Méthodes : Les tendances de 105 espèces ont été estimées en utilisant les données de 2001-2007 obtenues par des observateurs qui procèdent aux dénombrements 1100 points par rapport à 1535 places choisies au hasard. J'ai estimé que l'augmentation moyenne du nombre détectés entre le premier et toutes les années suivantes de l'enquête sur un site. Résultats : Les observateurs comptent 4,3% d'oiseaux en plus les années suivantes que durant la première année de l'enquête. Cet effet première année a diminué de 2001 à 2007 (en moyenne de 2% par an). Il n'était pas lié à la plupart des variables connues pour influencer la probabilité de détection des espèces. Seules les espèces avec des chants de faibles fréquences (de 0,5 à 8 kHz ici) affichent une plus grande augmentation du nombre détecté localement. Conclusion L'effet première année détecté était le résultat de la méthode d'apprentissage des nouveaux observateurs qui n'avaient pas précédemment menées de comptage ponctuels ou visité des sites choisis au hasard. L'effet d'apprentissage a été plus important pour les espèces avec des chants de fréquence faible qui sont plus difficiles à entendre durant le chant des oiseaux à l'aube
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Estimating species richness with capture–recapture models: choice of model when sampling in heterogeneous conditions: Capsule The capture–recapture heterogeneity model M(h) can be used confidently to estimate species richness when using Breeding Bird
2005Co-Authors: Frederic JiguetAbstract:To cite this article: Frederic Jiguet , Olivier Renault & Aurelie Petiau (2005) Estimating species richness with capture–recapture models: choice of model when sampling in heterogeneous conditions: Capsule The capture–recapture heterogeneity model M(h) can be used confidently to estimate species richness when using Breeding Bird Survey (BBS) data., Bird Study, 52:2, 180-187, DOI: 10.1080/00063650509461389
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estimating species richness with capture recapture models choice of model when sampling in heterogeneous conditions capsule the capture recapture heterogeneity model m h can be used confidently to estimate species richness when using Breeding Bird su
2005Co-Authors: Frederic JiguetAbstract:To cite this article: Frederic Jiguet , Olivier Renault & Aurelie Petiau (2005) Estimating species richness with capture–recapture models: choice of model when sampling in heterogeneous conditions: Capsule The capture–recapture heterogeneity model M(h) can be used confidently to estimate species richness when using Breeding Bird Survey (BBS) data., Bird Study, 52:2, 180-187, DOI: 10.1080/00063650509461389
Keith L. Pardieck - One of the best experts on this subject based on the ideXlab platform.
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Consistency counts: Modeling the effects of a change in protocol on Breeding Bird Survey counts
The Condor, 2019Co-Authors: John R. Sauer, William A Link, Keith L. Pardieck, David J. Ziolkowski, Daniel J. TwedtAbstract: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 nonrandom BBS Survey routes in the southeastern United States. Observers on selected routes employed a time–distance protocol in which they recorded Birds in 1–min intervals and in 2 distance categories. We hypothesized that processing and recording observations using this time–distance protocol could cause observers to count fewer Birds relative to observers using the standard protocol. We used a hierarchical log–linear model with a categorical covariate associated with protocol (standard vs. time–distance) to assess whether use of the time–distance protocol had a measurable effect on counting Birds along BBS routes. We applied this model to BBS data from portions of 8 states in which the time–distance protocol was implemented and estimated a protocol effect for 167 Bird species. We documented a significant overall effect of the time–distance protocol on observers'counts of Birds. On average, the effect of the time–distance protocol was a 10% decline in counted Birds; 80% of species had lower counts when the time–distance protocol was used on a Survey route. However, because the time–distance protocol was only used on a small portion of the operational BBS routes and for a limited time, including the covariate for the time–distance protocol data had insignificant effects on analysis of population change. Although the covariate controlled for the effects of the time–distance protocol in BBS data, the results emphasize the importance of standardization as well as a need to track and, if necessary, control in analyses for changes in counting procedures along BBS routes.
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Expanding the North American Breeding Bird Survey Analysis to Include Additional Species and Regions
Journal of Fish and Wildlife Management, 2017Co-Authors: John R. Sauer, Keith L. Pardieck, David J. Ziolkowski, Daniel K. Niven, William A LinkAbstract:Abstract The North American Breeding Bird Survey (BBS) contains data for >700 Bird species, but analyses often focus on a core group of ∼420 species. We analyzed data for 122 species of North Ameri...
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The first 50 years of the North American Breeding Bird Survey
The Condor, 2017Co-Authors: John R. Sauer, Keith L. Pardieck, David J. Ziolkowski, Adam C. Smith, Marie-anne R. Hudson, Vicente Rodriguez, Humberto Berlanga, Daniel K. Niven, William A LinkAbstract:ABSTRACT The vision of Chandler (Chan) S. Robbins for a continental-scale omnibus Survey of Breeding Birds led to the development of the North American Breeding Bird Survey (BBS). Chan was uniquely suited to develop the BBS. His position as a government scientist had given him experience with designing and implementing continental-scale Surveys, his research background made him an effective advocate of the need for a Survey to monitor pesticide effects on Birds, and his prominence in the Birding community gave him connections to infrastructure—a network of qualified volunteer Birders who could conduct roadside Surveys with standardized point counts. Having started in the eastern United States and the Atlantic provinces of Canada in 1966, the BBS now provides population change information for ∼546 species in the continental United States and Canada, and recently initiated routes in Mexico promise to greatly expand the areas and species covered by the Survey. Although Survey protocols have remained unchange...
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The role of the North American Breeding Bird Survey in conservation
The Condor, 2017Co-Authors: Marie-anne R. Hudson, Adam C. Smith, Charles M. Francis, Kate J. Campbell, Constance M. Downes, Keith L. PardieckAbstract:ABSTRACT The North American Breeding Bird Survey (BBS) was established in 1966 in response to a lack of quantitative data on changes in the populations of many Bird species at a continental scale, especially songBirds. The BBS now provides the most reliable regional and continental trends and annual indices of abundance available for >500 Bird species. This paper reviews some of the ways in which BBS data have contributed to Bird conservation in North America over the past 50 yr, and highlights future program enhancement opportunities. BBS data have contributed to the listing of species under the Canadian Species at Risk Act and, in a few cases, have informed species assessments under the U.S. Endangered Species Act. By raising awareness of population changes, the BBS has helped to motivate Bird conservation efforts through the creation of Partners in Flight. BBS data have been used to determine priority species and locations for conservation action at regional and national scales through Bird Conservatio...
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How well do route Survey areas represent landscapes at larger spatial extents? An analysis of land cover composition along Breeding Bird Survey routes
The Condor, 2017Co-Authors: Joseph A. Veech, Keith L. Pardieck, David J. ZiolkowskiAbstract:ABSTRACT The occurrence of Birds in a Survey unit is partly determined by the habitat present. Moreover, some Bird species preferentially avoid some land cover types and are attracted to others. As such, land cover composition within the 400 m Survey areas along a Breeding Bird Survey (BBS) route clearly influences the species available to be detected. Ideally, to extend Survey results to the larger landscape, land cover composition within the Survey area should be similar to that at larger spatial extents defining the landscape. Such representativeness helps minimize possible roadside effects (bias), here defined as differences in Bird species composition and abundance along a roadside as compared to a larger surrounding landscape. We used land cover data from the 2011 National Land Cover Database to examine representativeness of land cover composition along routes. Using ArcGIS, the percentages of each of 15 land cover types within 400 m buffers along 2,696 U.S. BBS routes were calculated and compared t...
David G Noble - One of the best experts on this subject based on the ideXlab platform.
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The effect of observer experience on English Breeding Bird Survey population trends
Bird Study, 2010Co-Authors: Sarah M. Eglington, Sarah E. Davis, Andrew Joys, Dan E. Chamberlain, David G NobleAbstract:Capsule Including observer effects in population models is unlikely to improve population trend estimates. Aims We test the hypothesis that the observer's experience has a significant effect on the detection of Birds, and subsequently impacts on estimates of abundance and population trends. Methods Two models were used to test the effect of observer experience: (1) assuming that effects of observer naivety operate only in the first year, and express experience as a binomial variable; (2) assuming effects of experience improve year‐on‐year, and express as a continuous variable. For each model, experience was included in annual site‐by‐year log‐linear models with Poisson error terms. Results Significant observer‐experience effects were found for up to half of the species analysed depending on the model. However, there were no patterns in the direction of these negative effects. Importantly, including observer experience in analyses of population trends significantly affected estimates of change in only one ...
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The development of Bird indicators for British fresh waters and wetlands.
Aquatic Conservation: Marine and Freshwater Ecosystems, 2009Co-Authors: Mark Everard, David G NobleAbstract:1. Population trends of Breeding Birds in freshwater habitats generated from long-term monitoring in the UK provide biodiversity indicators for some wetland habitats. 2. Bird species were assigned to target wetland habitats based on evidence of their association and data availability. Species trends for each habitat were then modelled using a range of Survey data from BTO schemes including the Common Bird Census, Breeding Bird Survey, Waterways Bird Survey and Waterways Breeding Bird Survey. 3. Smoothed population trends for the selected species were combined to produce a composite indicator for Birds of selected waterways and wetland habitats for England. This forms one of the three strands of a new aggregate Bird indicator in the UK. 4. These indicators show generally that Breeding Bird species associated with slow-moving waterways and standing waters have increased over the past 30 years. Over the same period, species associated with fast-flowing waters show modest declines, species associated with reed habitats have declined and recovered, while species associated with wet grasslands, including marshes, have declined. 5. Further monitoring and exploration of the relationship between these indicators is needed to improve confidence in species trends and identifying potential drivers of change in freshwater and wetland habitats. Copyright © 2009 John Wiley & Sons, Ltd.
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the Breeding Bird Survey for mapping britain s Birds a preliminary assessment of performance at two spatial scales
Revista catalana d'ornitologia = Catalan journal of ornithology, 2008Co-Authors: Stuart E Newson, David G NobleAbstract:Advances in the application of geostatistics in recent years have improved the precision of predicting occurrence or relative abundance at non-Surveyed sites and so allow the potential for producing reliable maps over the entire area of interest. We evaluate the use of geostatistics for producing statistically valid maps of relative abundance at two spatial scales from annual Bird monitoring data collected by the UK Breeding Bird Survey (BBS). Whilst development of an approach that optimizes the precision of this methodology is being explored currently, it is important to explore the extent to which the BBS, with about 2,000 1-km squares Surveyed annually (<1 % of the UK), is adequate for producing useful maps. To this end, we compare relative abundance, interpolated from 2003 BBS data for 96 species, with independent data collected for these species through intensive Survey effort during the last Breeding Atlas of 1988-91. Comparisons are made at two spatial scales: at a regional scale with 125 regions and at a local scale comprising some 2,882 10-km squares. Whilst the BBS and Atlas measures of abundance are not the same, and there are over ten years between the collection these data, during which time several species have undergone large population declines or increases and contractions or expansions in range, it was encouraging to find that there was no significant difference at a regional scale between measures of abundance for 84 of the 96 species (88%). At a local scale, there was no significant difference between measures of abundance for 17 of the 96 species (18%). Differences between the interpolated BBS and Atlas measures of abundance at both spatial scales can be explained in part by real changes in abundance between years although, as one would expect, the BBS provides greatest map reliability for the most widespread species as shown by a strong positive relationship between map similarity and number of occupied BBS squares. However, we have yet to examine the extent to which habitat and other landscape variables may improve our predictions for species with patchy distributions.
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modelling population changes using data from different Surveys the common Birds census and the Breeding Bird Survey
Bird Study, 2007Co-Authors: Stephen N Freeman, David G Noble, Stuart E Newson, Stephen R BaillieAbstract:Capsule A method for producing and validating long-term population indices using data from the Common Birds Census and its successor, the Breeding Bird Survey, is described. Aim To investigate a means of combining site-specific records from two very different Surveys into reliable population indices. Methods A generalized linear model is described for Common Birds Census (CBC) and Breeding Bird Survey (BBS) data, and used to identify species and geographical regions for which the resulting temporal trends are comparable, and hence derive long-term trends that straddle the overlap of the two Surveys. Results From 1994 to 2000, when both the CBC and the BBS were in operation, no significant difference in population trends in southeastern Britain between the two Surveys was detected for the vast majority of the 73 species considered. CBC data are limited outside this region, but an analysis of BBS data over the same period showed that the trends outside this region were significantly different for around hal...
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evaluating the Breeding Bird Survey for producing national population size and density estimates
Bird Study, 2005Co-Authors: Stuart E Newson, David G Noble, Stephen R Baillie, Rick J W Woodburn, Richard D GregoryAbstract:Capsule The BBS has potential for producing better estimates of habitat-specific densities and population sizes for many UK Bird populations than those available previously. Aims To examine the use of the Breeding Bird Survey (BBS) in providing unbiased national population and habitat-specific density estimates of British Birds. Methods Line transect data collected by volunteers in 1998 from 2287 1-km squares across the UK were analysed using distance sampling methods to calculate habitat-specific density and abundance estimates. For each species, the habitat-specific decline in detectability with distance from a transect line was modelled and applied at a regional level to incorporate variation in sampling intensity in different areas of the country. Results National population and density estimates calculated here were at a magnitude expected for at least seven species in this study. However, national population size estimates were higher than expected for Starling Sturnus vulgaris, House Sparrow Passer...