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projects > estimating abundance of the cape sable seaside sparrow and other species of concern in south florida

Estimating abundance of the Cape Sable Seaside Sparrow and other species of concern in south Florida

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Project Investigator: Robert Dorazio

Project Start Date: 2014 End Date: 2015

Recent Funding: (FY14) USGS GE PES, USGS SESC


Data analyses will be conducted by developing probability-based models of latent ecological state variables and conditional models of observable quantities that depend on those state variables. Either classical or Bayesian modes of inference will be used, as needed. All models will be implemented using the R programming language.

Cape Sable Seaside Sparrow (CSSS) is an endangered bird whose reproductive success depends in large part on how water in the Everglades is managed. Water levels during the CSSS breeding season must be maintained at low level to avoid flooding the nests. At other times, water levels must be maintained to promote growth of the plant communities these birds prefer. Everglades restoration planners require robust and quantitative information on the changing abundance of various subpopulations of the CSSS, and how these changes have been influenced as a result of variable hydrologic conditions. Annual surveys of the CSSS have taken place since the early 1990s. During this time, significant decreases in the bird counts of a few of the subpopulations have been recorded, suggesting a decline in CSSS abundance. However, past attempts to quantify detection probability during these surveys were extremely limited. Moreover, there have been no attempts to determine how bird detection probability during these surveys changed with environmental covariates such as habitat type or water levels. As such, estimates of CSSS abundance based on the annual record of bird counts may be subject to considerable error or bias. This lack of confidence in CSSS population estimates is hindering progress on Everglades restoration planning.

Objectives of this study are to:

  • Review historic CSSS bird count data, abundance estimates and results of efforts to quantify detection probability.
  • In consultation with the US FWS and the NPS review CSSS findings to date and provide recommendations for future investigations, including survey design, survey protocol and population modeling.
  • Develop statistical models of species abundance or occurrence to be used in assessments of Everglades restoration (i.e., wildlife indicators, endangered species, or species of management concern). Models should correct for errors in detection of individual species.

Work Plans


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Script last updated: 02 December 2016 @ 02:34 PM by THF. Record creator: KP. Record last updated by: KP.