Dataset Information

Modeling trends from North American breeding bird survey data: a spatially explicit approach.

ABSTRACT: Population trends, defined as interval-specific proportional changes in population size, are often used to help identify species of conservation interest. Efficient modeling of such trends depends on the consideration of the correlation of population changes with key spatial and environmental covariates. This can provide insights into causal mechanisms and allow spatially explicit summaries at scales that are of interest to management agencies. We expand the hierarchical modeling framework used in the North American Breeding Bird Survey (BBS) by developing a spatially explicit model of temporal trend using a conditional autoregressive (CAR) model. By adopting a formal spatial model for abundance, we produce spatially explicit abundance and trend estimates. Analyses based on large-scale geographic strata such as Bird Conservation Regions (BCR) can suffer from basic imbalances in spatial sampling. Our approach addresses this issue by providing an explicit weighting based on the fundamental sample allocation unit of the BBS. We applied the spatial model to three species from the BBS. Species have been chosen based upon their well-known population change patterns, which allows us to evaluate the quality of our model and the biological meaning of our estimates. We also compare our results with the ones obtained for BCRs using a nonspatial hierarchical model (Sauer and Link 2011). Globally, estimates for mean trends are consistent between the two approaches but spatial estimates provide much more precise trend estimates in regions on the edges of species ranges that were poorly estimated in non-spatial analyses. Incorporating a spatial component in the analysis not only allows us to obtain relevant and biologically meaningful estimates for population trends, but also enables us to provide a flexible framework in order to obtain trend estimates for any area.

SUBMITTER: Bled F

PROVIDER: S-EPMC3862490 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Modeling trends from North American breeding bird survey data: a spatially explicit approach.

Bled Florent F Sauer John J Pardieck Keith K Doherty Paul P Royle J Andrew JA

PloS one 20131213 12

Population trends, defined as interval-specific proportional changes in population size, are often used to help identify species of conservation interest. Efficient modeling of such trends depends on the consideration of the correlation of population changes with key spatial and environmental covariates. This can provide insights into causal mechanisms and allow spatially explicit summaries at scales that are of interest to management agencies. We expand the hierarchical modeling framework used ...[more]

PMID: 24349141

Similar Datasets

Project description:Insecticide usage in the United States is ubiquitous in urban, suburban, and rural environments. There is accumulating evidence that insecticides adversely affect non-target wildlife species, including birds, causing mortality, reproductive impairment, and indirect effects through loss of prey base, and the type and magnitude of such effects differs by chemical class, or mode of action. In evaluating data for an insecticide registration application and for registration review, scientists at the United States Environmental Protection Agency (USEPA) assess the fate of the insecticide and the risk the insecticide poses to the environment and non-target wildlife. Current USEPA risk assessments for pesticides generally rely on endpoints from laboratory based toxicity studies focused on groups of individuals and do not directly assess population-level endpoints. In this paper, we present a mechanistic model, which allows risk assessors to estimate the effects of insecticide exposure on the survival and seasonal productivity of birds known to forage in agricultural fields during their breeding season. This model relies on individual-based toxicity data and translates effects into endpoints meaningful at the population level (i.e., magnitude of mortality and reproductive impairment). The model was created from two existing USEPA avian risk assessment models, the Terrestrial Investigation Model (TIM v.3.0) and the Markov Chain Nest Productivity model (MCnest). The integrated TIM/MCnest model was used to assess the relative risk of 12 insecticides applied via aerial spray to control corn pests on a suite of 31 avian species known to forage in cornfields in agroecosystems of the Midwest, USA. We found extensive differences in risk to birds among insecticides, with chlorpyrifos and malathion (organophosphates) generally posing the greatest risk, and bifenthrin and λ-cyhalothrin (pyrethroids) posing the least risk. Comparative sensitivity analysis across the 31 species showed that ecological trait parameters related to the timing of breeding and reproductive output per nest attempt offered the greatest explanatory power for predicting the magnitude of risk. An important advantage of TIM/MCnest is that it allows risk assessors to rationally combine both acute (lethal) and chronic (reproductive) effects into a single unified measure of risk.

Project description:BackgroundIn 2010, coincident with the 100th anniversary of Flexner's sentinel report, the Carnegie Foundation published an updated review of North American medical education and challenged medical schools to initiate further educational reforms. Specific recommendations pertained to a) ensuring standardized outcomes while allowing for individualized processes, b) integrating foundational knowledge with clinical experience, c) cultivating habits of inquiry and innovation and d) professional identity formation. As we approach the 10-year anniversary of this latest report, we sought to determine what type of curricular revisions have been emerging within the past decade and what types of challenges have been encountered along the way?MethodsIn 2018, an electronic survey was sent to all 166 Liaison Committee on Medical Education (LCME) accredited North American Medical Schools, using the points of contact (educational deans) that were listed in a publicly available, Association of American Medical Colleges database. Free text comments were grouped into themes using the constant-comparative technique.ResultsSixty unique responses yielding a 36.14% response rate. The distribution of responses was proportionally representative of the distribution of public vs. private, old vs. new vs. established North American medical schools. Self-reported curricular changes aggregated into five main themes: Changes in curricular structure/organization, changes in curricular content, changes in curricular delivery, changes in assessment, and changes involving increased use of technology/informatics. Challenges were predominantly focused on overcoming faculty resistance, faculty development, securing adequate resourcing, change management, and competition for limited amounts of curricular time.ConclusionsChanges in curricular organization, content, delivery, assessment and the use of technology reflect reforms that are broad and deep. Empowering faculty to "let go" of familiar constructs/processes requires strong leadership, particularly when initiating particularly disruptive curricular changes, such as relocating the Step 1 examination or shifting to a competency-based curriculum. While North American medical schools are responding to the calls for action described in the second (2010) Carnegie Foundation report, the full vision has yet to be achieved.

Dataset Information

Modeling trends from North American breeding bird survey data: a spatially explicit approach.

Publications

Modeling trends from North American breeding bird survey data: a spatially explicit approach.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets