Grantee Research Project Results
2002 Progress Report: Individual Variability, Environmental Stressors, and Sampling Uncertainty in Wildlife Risk Assessment
EPA Grant Number: R829088Title: Individual Variability, Environmental Stressors, and Sampling Uncertainty in Wildlife Risk Assessment
Investigators: Kendall, Bruce E. , Fox, Gordon A.
Institution: University of California - Santa Barbara , University of South Florida
EPA Project Officer: Packard, Benjamin H
Project Period: September 1, 2001 through August 31, 2004 (Extended to December 31, 2005)
Project Period Covered by this Report: September 1, 2001 through August 31, 2002
Project Amount: $426,954
RFA: Wildlife Risk Assessment (2001) RFA Text | Recipients Lists
Research Category: Biology/Life Sciences , Ecological Indicators/Assessment/Restoration , Aquatic Ecosystems
Objective:
This research project has two overall objectives, each addressing four specific questions. The first objective is to determine the statistical power of assessments. More specifically:
- Under what circumstances do life table response experiments (LTREs) have the power to detect responses to meaningful environmental variation?
- Under what circumstances do correlation analyses of field data have the power to detect responses to meaningful environmental variation?
- How are these predictions affected by multiple, unmeasured stressors?
- How is the power of these approaches changed by measuring organism condition?
The second objective is to examine the importance of variability in the expected demographic performance of individuals. More specifically:
- What is the net effect of a spatially heterogeneous stressor?
- How does this heterogeneity affect the power of LTRE and correlation analyses?
- What is the pattern of demographic variability in fecundity?
- What is the magnitude of individual variability in demography?
Progress Summary:
During Year 1 of the project, we Purchased and installed a high-performance
computer comprising 9 dual-processor 2-Ghz Pentium IV servers running Windows
2000. This primarily will be used for the power analyses in the first objective.
Four personnel will assist with the project doing literature searches for data
on fecundity distributions and demographic variability, as well as providing
support for data management and code development.
For the first project objective, progress has been made in code development
for power analysis in a simple population model.
For the second objective, progress has been made in several research areas:
- We have made substantial advancements on general theory, extending our initial work on how individual variability translates into population-level variability and describing how this variability affects extinction risk (see publications/presentations).
- An extensive search of the literature for data on clutch-size distributions of reptiles and litter-size distributions of mammals is ongoing.
- A literature search for information on demographic variability associated with varying stressor intensity is ongoing.
- Preliminary analysis of data on Florida Scrub Jay indicates substantial individual variation in demographic performance.
Future Activities:
Future activities are to: (1) complete the coding for the power analyses and begin running the analyses; (2) complete the analyses of clutch/litter-size distributions and analyze a general model for demographic stochasticity in fecundity; (3) continue literature surveys to determine the magnitude of individual variability in demography; (4) conduct detailed analyses of 30 years of data on a Florida Scrub Jay population, determining the structure of the among-individual variation and analyzing its effect on population dynamics; and (5) begin model development to examine questions about a spatially heterogeneous stressor.Journal Articles on this Report : 2 Displayed | Download in RIS Format
| Other project views: | All 15 publications | 4 publications in selected types | All 4 journal articles |
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Fox GA. Extinction risk of heterogeneous populations. Ecology 2005;86(5):1191-1198. |
R829088 (2002) R829088 (Final) |
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Kendall BE, Fox GA. Variation among individuals and reduced demographic stochasticity. Conservation Biology 2002;16(1):109-116. |
R829088 (2002) R829088 (Final) |
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Supplemental Keywords:
risk assessment, ecological effects, sensitive populations, population, terrestrial, conservation, ecology, mathematics, Florida, FL, modeling, analytical., RFA, Scientific Discipline, Health, Economic, Social, & Behavioral Science Research Program, Ecosystem Protection/Environmental Exposure & Risk, RESEARCH, Applied Math & Statistics, Ecology, Ecosystem/Assessment/Indicators, exploratory research environmental biology, wildlife, Models, Ecological Effects - Environmental Exposure & Risk, Susceptibility/Sensitive Population/Genetic Susceptibility, Ecological Risk Assessment, Ecology and Ecosystems, genetic susceptability, Environmental Statistics, Ecological Indicators, ecological exposure, risk assessment, predicting risk, sampling designs, stressors, ecosystem assessment, demographic data, environmental stressor, individual variability, Wildlife Risk Assessment, sampling uncertainty, environmental sampling, animal models, statistical models, risk models, data analysis, sampling, life table response experimentsRelevant Websites:
http://www.esm.ucsb.edu/fac_staff/fac/kendall/default.html
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http://chuma.cas.usf.edu/~gfox/
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Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.