Demographic Analysis of the Endangered Cape Sable Seaside Sparrow
USGS researchers will examine how hydrology and landscape vegetation changes impact Cape Sable Seaside Sparrow survival and population growth.
The Science Issue and Relevance: The Cape Sable Seaside Sparrow (CSSS; Ammospiza maritima mirabilis) is a federally endangered species endemic to southern Florida and occurs in the freshwater prairies of Everglades National Park and Big Cypress National Preserve. Estimates of the CSSS population indicate a 63% decline since 1981 across its fragmented range, which is delineated by six, small subpopulations (A-F, Fig. 1). The major threats to the CSSS are attributed to changes in the short-hydroperiod marl prairie habitat, specifically altered hydroperiods, and associated changes in fire frequency. Other threats to the CSSS and its habitat are nest predation and climate change. Over four decades of field research has been conducted on the CSSS, but a statistically robust analysis of the population’s demographic parameters utilizing all available data has yet to be completed. Such an analysis would provide a more accurate assessment of the status of the CSSS population and shed light on the viability of subpopulations considering potential future conditions. Our objectives are to (1) quantify the effects of hydrologic and environmental factors on demographic parameters (population size, individual survival, nest survival) and (2) quantify the relative importance of demographic parameters on population change.
Methodology for Addressing the Issue: To meet our objectives, we will examine how short- and long-term hydrology and landscape vegetation changes impact CSSS survival and population growth. We will use data from range-wide surveys and mark-recapture/resights to estimate yearly population sizes and individual survival and test how population size and survival change in response to hydrologic and vegetation community variables. In addition, we will estimate daily nest survival and test how nesting success changes in response to hydrology, vegetation, and population level parameters. Finally, we plan to employ an integrated population modeling approach to identify the demographic parameters that most impact population change. These results will provide insight into the causes of declines in the CSSS population.
Future Steps: These analyses will directly inform an individual-based model (IBM) that can be used to conduct targeted population viability analyses. The IBM would simulate CSSS populations under different restoration scenarios and population scenarios (such as the sudden extinction of one subpopulation) to support U.S. Fish and Wildlife Service recovery planning and land management actions by Everglades National Park.
Related Tools:
Knowledge Synthesis of Cape Sable Seaside Sparrow Science
Everglades Depth Estimation Network (EDEN)
Modeling Spatial Habitat Quality for the Cape Sable Seaside Sparrow
Joint Ecosystem Modeling: Cape Sable Seaside Sparrow Helper
Joint Ecosystem Modeling: Cape Sable Seaside Sparrow Marl Prairie Indicator
USGS researchers will examine how hydrology and landscape vegetation changes impact Cape Sable Seaside Sparrow survival and population growth.
The Science Issue and Relevance: The Cape Sable Seaside Sparrow (CSSS; Ammospiza maritima mirabilis) is a federally endangered species endemic to southern Florida and occurs in the freshwater prairies of Everglades National Park and Big Cypress National Preserve. Estimates of the CSSS population indicate a 63% decline since 1981 across its fragmented range, which is delineated by six, small subpopulations (A-F, Fig. 1). The major threats to the CSSS are attributed to changes in the short-hydroperiod marl prairie habitat, specifically altered hydroperiods, and associated changes in fire frequency. Other threats to the CSSS and its habitat are nest predation and climate change. Over four decades of field research has been conducted on the CSSS, but a statistically robust analysis of the population’s demographic parameters utilizing all available data has yet to be completed. Such an analysis would provide a more accurate assessment of the status of the CSSS population and shed light on the viability of subpopulations considering potential future conditions. Our objectives are to (1) quantify the effects of hydrologic and environmental factors on demographic parameters (population size, individual survival, nest survival) and (2) quantify the relative importance of demographic parameters on population change.
Methodology for Addressing the Issue: To meet our objectives, we will examine how short- and long-term hydrology and landscape vegetation changes impact CSSS survival and population growth. We will use data from range-wide surveys and mark-recapture/resights to estimate yearly population sizes and individual survival and test how population size and survival change in response to hydrologic and vegetation community variables. In addition, we will estimate daily nest survival and test how nesting success changes in response to hydrology, vegetation, and population level parameters. Finally, we plan to employ an integrated population modeling approach to identify the demographic parameters that most impact population change. These results will provide insight into the causes of declines in the CSSS population.
Future Steps: These analyses will directly inform an individual-based model (IBM) that can be used to conduct targeted population viability analyses. The IBM would simulate CSSS populations under different restoration scenarios and population scenarios (such as the sudden extinction of one subpopulation) to support U.S. Fish and Wildlife Service recovery planning and land management actions by Everglades National Park.
Related Tools: