Our I.iviiii; Resources — Rcpnics ami Amphihians 



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The American alligator (Alligator mississip- 

 piensis) is an integral component of wetland 

 ecosystems in Florida. Alligators also provide 

 aesthetic, educational, recreational, and eco- 

 nomic benefits to humans. Because of the com- 

 mercial value of alligator hides for making 

 high-quality leather products, alligator hunting 

 was a major economic and recreational pursuit 

 of many Floridians from the mid-1800"s to 

 1970. The Florida alligator population varied 

 considerably during the 1900"s in response to 

 fluctuating hunting pressure caused by unstable 

 markets for luxury leather products. 



The declining abundance of alligators during 

 the late 195()"s and early 1960's led to the 1967 

 classification of the Florida alligator population 

 as endangered throughout its range. Federal and 

 international regulations imposed during the 

 1970"s and 198(rs helped control trade of alli- 

 gator hides, and illegal hunting of alligators was 

 checked. The Florida alligator population 

 responded immediately to protection and was 

 reclassified as threatened in 1977 and as threat- 

 ened because of its similarity in appearance to 

 the American crocodile {Crocodylus acutus) in 

 1985 (Neal 1985). 



Assessments of Florida's alligator popula- 

 tion were based on sporadic surveys before 

 1974 (Wood et al. 1985). The Florida Game and 

 Fresh Water Fish Commission implemented 

 annual night-light surveys that used spotlights 

 to detect alligator eyeshine in 1974 to provide a 

 more objective basis for assessing population 

 trends (Wood et al. 1985). Although all areas 

 were not sampled every year, these data are the 

 best available for alligator populations in 

 Florida and are useful for estimating population 

 trends (Woodward and Moore 1990). Because 

 survey areas were not a random sample of all 

 alligator habitat in Florida, trend results are 

 applicable only to deepwater habitats and navi- 

 gable wetlands. 



Design of Alligator Surveys, 

 1974-92 



We conducted night-light counts (Woodward 

 and Marion 1978) with high-intensity spotlights 

 from boats on 54 areas throughout Florida (Fig. 

 1) during 1974-92 (Woodward and Moore 

 1990). The number of areas surveyed in any 

 year ranged from 7 in 1974 to 43 in 1980. In 

 1983 the number of areas surveyed was reduced 

 to 22 to allow observers to conduct replicate 

 counts on areas each year (Fig. 1 ). Eighteen of 

 the 22 areas were subjected to alligator harvests 

 of some type. 



American 

 Alligators in 

 Florida 



by 



Allan R. Woodward 



Florida Game and Fresh 



Water Fish Commission 



Clinton T. Moore 

 U.S. Fish and Wildlife Service 



Fig. 1. Locations of survey areas for night-light counts 

 alligators in Florida, 1974-92. 



We analyzed observed densities of alligators 

 per kilometer (0.62 mile) of shoreline to esti- 

 mate trends for each area during the periods 

 1974-92 and 1983-92. Size classes correspond- 

 ed to the overall population, juveniles (0.3-1.2 

 m [ 1 -4 ft] ). harvestable sizes {1.2m or longer [4 

 ft or longer]), and adults (1.8 m or longer [6 ft 

 or longer]; hatchlings less than 0.3 m long [1 ft] 

 were excluded from trend analysis). 



Count densities represent only alligators 

 observed during the survey. Most (more than 

 65%) alligators were submerged during surveys 

 and not detected (Murphy 1977: Brandt 1989; 

 Woodward and Linda 1993). Alligators in wet- 

 lands adjacent to surveyed areas may have been 

 undetected (Woodward and Linda 1993). 

 Counts, however, do provide a relative measure 

 of alligator abundance that is useful for estimat- 

 ing population trends, provided that rates of 

 detection do not vary annually. 



Status and Trends 



From 1974 to 1992, the density of alligators 

 on surveyed wetlands increased an average 41% 



Alligators at dusk. Payne's Praine 

 State Preser\'e. Florida. 



