¹U. S. Geological Survey,
 Florida Cooperative Fish and Wildlife Research Unit
Building 810, University of Florida, Gainesville, FL 32611

²U.S. Geological Survey, , FISC
 University of Florida Field Station
3205 College Ave, Ft. Lauderdale, FL 33314

³University of Florida
Ft. Lauderdale Research and Education Center
3205 College Ave, Ft. Lauderdale, FL 33314

Abstract

Drainage and diking projects in the Everglades have resulted in the creation of hundreds of kilometers of canals. In this research, we address the effects that canal habitats have on alligator (Alligator mississippiensis) population ecology. This project includes analyses of alligator hole characteristics, home range, habitat preference, population density and size structure, physical condition, thermoregulation, and production. This continuing research is being conducted throughout the Everglades including ARM Loxahatchee National Wildlife Refuge (LOX), Water Conservation Areas (WCA) 2 and 3, Big Cypress National Preserve (BICY), and Everglades National Park (ENP).

Introduction

The alligator is a keystone species and an ecosystem engineer that physically influences the floral and faunal characteristics of the Everglades landscape. Information on Everglades alligator population dynamics is required to make management decisions concerning the importance of man-made and natural habitats to the species.

Restoration planning is currently underway for the Everglades under the Comprehensive Everglades Restoration Plan.  A major unanswered question involves landscape decompartmentalization effects on wildlife populations.  Our research demonstrates the effects of canal habitats on alligator populations. This information can be used directly to make restoration and management decisions, and indirectly through Across-Trophic Level System Simulation (ATLSS) model inputs and parameter estimates.

It has been accepted that the cumulative effects of annual flood and drought cycles in the altered Everglades system has negatively impacted alligator populations. The altered Everglades also contains hundreds of kilometers of canals.  The extent to which canal presence has altered the habitats and reproductive parameters of the "keystone" alligator in this system is not fully understood (SFERT Science Subgroup 1997).

Objectives

In this research we address the effects that canal habitats have on alligator (Alligator mississippiensis) population ecology.  Research objectives included understanding the following in canal and natural marsh habitats:

Alligator population density and size structure

Literature Cited

Mazzotti, F. J., L. A. Brandt, M. R. Campbell, and M. Palmer.  1999. An Ecological Characterization of Everglades Alligator Holes.  Final Annual Report to Everglades Agricultural Area Environmental Protection District, NFW. UF-IFAS, Belle Glade, FL. 82 pp.

South Florida Ecosystem Restoration Taskforce, Science Subgroup. 1997. Ecologic and precursor success criteria for south Florida ecosystem restoration. A report to the working group of the South Florida Ecosystem Restoration Task Force, Chapter 12.
 

Acknowledgements

This research was supported in significant part by DOI's Critical Ecosystem Studies Initiative, a special funding initiative for Everglades restoration administered by the National Park Service; and in part by USGS's Florida Integrated Science Center.

We would like to thank Mark Campbell, Adam Finger, Tori Foster, Phillip George, Stan Howarter, Corey Morea, Michelle Palmer, Travis Tuten, and Christa Zweig for technical and field work assistance.

Laura Brandt and Loxahatchee National Wildlife Refuge, Nat Frazer, Debra Hughes, Barbara Fesler, and Alan Woodward provided advice and logistical support.