Dry years decrease abundance of American alligators in the Florida Everglades

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The Everglades has been greatly reduced and is threatened by land use change and altered hydrology. The Comprehensive Everglades Restoration Plan calls for monitoring and assessment of key ecosystem attributes, one of which is abundance of American alligators. We examined 10 years of alligator night spotlight counts from Arthur R. Marshall Loxahatchee National Wildlife Refuge along two canals and in the interior marsh to determine trends and how dry years affect alligator abundance. Alligators showed population response to hydrologic conditions. In particular, there were declines in abundance after dry years followed by an apparent recovery in abundance in subsequent years. Increases in abundance were lower in the marsh than L-40 Canal. In addition, there was evidence that intensity of dry events affected population dynamics with greater declines observed in years with drier conditions. Results revealed that overall population of alligators increased from 2004 to 2013, but that increases varied by survey route. These results demonstrate that dry years cause a decline in alligator abundance proportional to the intensity of the dry event, and that it is important to make a distinction between canals and marsh when measuring alligator response to hydrology.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Dry years decrease abundance of American alligators in the Florida Everglades
Series title Wetlands
DOI 10.1007/s13157-015-0677-8
Volume 35
Issue 5
Year Published 2015
Language English
Publisher Springer
Contributing office(s) Wetland and Aquatic Research Center
Description 11 p.
First page 865
Last page 875
Country United States
State Florida
Other Geospatial Arthur R. .Marshall Loxhatchee National Wildlife Refuge
Online Only (Y/N) N
Additional Online Files (Y/N) N
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