Across Trophic Level System Simulation (ATLSS) - Alligators

Proposals and Project Summaries Publications Related Link

The American Alligator (Alligator mississippiensis) is a keystone species of the South Florida Ecosystem. Population growth and survival depends directly on the hydrologic functioning of South Florida watersheds. Each of these watersheds has experienced, and continues to experience, substantial degradation. In fact, over half of the wetlands within central and southern Florida have been lost during the past century and those that remain have been highly fragmented and severely degraded (Weaver et al., 1994). Currently, planning is underway for what may become the largest ecosystem restoration ever undertaken. Although other endangered and keystone species occur within the ecosystem, the American Alligator's role as a top predator and its effect on the structuring of plant communities and associated aquatic animals (Mazzotti and Brandt, 1994) make it an ideal indicator of ecosystem health. The response of alligator populations to spatio-temporal changes in hydrological conditions throughout the South Florida Ecosystem are integral to the evaluation of any restoration alternative.

The ATLSS American Alligator Production Index (API) Model was developed as a coarse indicator of the yearly production potential (probability of producing nests and offspring successfully) for the American Alligator in South Florida based upon local habitat and hydrologic conditions. The production potential of this species is directly influenced by unique environmental conditions occurring throughout its range in Florida. The API model addresses only the effects of relative local habitat quality and hydrological dynamics. Consequently, this model should not be interpreted as providing estimates of population dynamics or viability. Further, the temporal extent of the model is not likely to encompass long-term changes in habitat quality. Particularly, stabilized hydrologic regimes may result in slow degradation or improvement of habitat not included in this model. Little verification of the model's performance was possible except for those populations in Everglades National Park and Water Conservation Areas 2 and 3. In addition, the density of essential landscape features (e.g. tree islands) within Water Conservation Area 1 (ARM Loxahatchee National Wildlife Refuge) are "best guess" approximations since the data are currently lacking.

Proposals

• 2001 (American Alligator Distribution, Thermoregulation, and Biotic Potential Relative to Hydroperiod in the Everglades)
• 2001 (Parameter Estimation and Population-Based Simulation Modeling of American Alligator Populations in Support of ATLSS)

Project Summaries

• 2001, 2002 (American Alligator Distribution, Thermoregulation, and Biotic Potential Relative to Hydroperiod in the Everglades)
• 2001, 2002 (Parameter Estimation and Population-Based Simulation Modeling of American Alligator Populations in Support of ATLSS)

Publications

Abstracts:

• American Alligator Distribution, Thermoregulation, and Biotic Potential Relative to Hydroperiod in the Everglades (from the South Florida Restoration Science Forum, May 1999)
• American Alligator Distribution, Thermoregulation, and Biotic Potential Relative to Hydroperiod in the Everglades (from the GEER Conference, December 2000)
• American Alligator Ecology (from the South Florida Restoration Science Forum, May 1999)
• The ATLSS American Alligator Population Model: Results from Restoration Alternatives (from the GEER Conference, April 2003)
• Body Condition Analysis for the American Alligator for Use in Everglades Restoration (from the GEER Conference, April 2003)
• The Effects of Everglades Food Items (Prey) on Crocodilian Growth, Development, and Fertility (from the South Florida Restoration Science Forum, May 1999)
• Evaluating the Effect of Salinity on a Simulated American Crocodile (Crocodylus acutus) Population (from the GEER Conference, April 2003)

  Flyer:

• American Alligator Population Ecology (available from the Center for Aquatic Resource Studies website. Please note that this is a (0.2 Mb) PDF file and requires the FREE Adobe Acrobat Reader® to be read.)

  Posters:

• Ecology of Everglades Alligator Holes (poster presented at 2003 GEER Conference)
• Home Range and Movement of Alligators in the Everglades (presented at the GEER Conference, December 2000)
• How is restoration improved by research on alligators and crocodiles? (from the South Florida Restoration Science Forum, May 1999)
• Modeling Alligator Production Probabilities in the Everglades (presented at the GEER Conference, December 2000)
• Role of American Alligator (Alligator mississippiensis) in Measuring Restoration Success in the Florida Everglades (poster presented at 2003 GEER Conference)
• Thermoregulation of the American Alligator in the Everglades (presented at the GEER Conference, December 2000)

Related Link

• ATLSS American Alligator Production Index Model (Basic Model Description)

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