American Alligator: Alligator mississippiensis
Genus/Species: Alligator mississippiensis
Common Name: American alligator
Federal Status: Threatened (Similarity of Appearance to the American Crocodile)
FL Status: Federally-designated Threatened (Similarity of Appearance)
FNAI Ranks: G5/S4 (Globally: Demonstrably Secure/State: Apparently Secure).
IUCN Status: LC (Least Concern)
The American alligator is a black reptile that can reach lengths of 13-14.7 feet (4-4.5 meters) and a weight in excess of 1,000 lbs (454 kilograms) (Florida Museum of Natural History, n.d.). A special feature of the alligator is its nostrils. The nostrils are upward facing on the long snout, which allows the alligator to breathe when its body is submerged (Smithsonian National Zoological Park, n.d.). Also, armored plates (scutes) cover the body. Alligators have a vertically flattened tail, and a light yellow throat and belly. Alligators are ectothermic (body temperature is externally regulated) and are generally active when external temperatures are 82-92°F (28-33°C). They stop feeding when the external temperature drops to 70°F (21°C), and they will go dormant (inactive) at (55°F) 13°C. While in a dormant stage, they can be found in burrows.
Adult alligators are opportunistic feeders (they feed on what is available). Adults feed on small mammals, birds, fish, turtles, and snakes; juveniles feed on small fish, insects, and amphibians. In the Everglades, alligators primarily feed on apple snails (P. Moler pers. comm. 2011).
Male alligators begin courting in early April and breeding occurs in May or June. The female builds the nest, which consists of debris, soil, and vegetation. The average clutch size is 32-46 eggs, which are laid in late June and early July. The eggs incubate for 60-65 days and hatch in late August or early September. Females reach maturity at 10-15 years old, whereas males mature at 8-12 years old.
Habitat and Distribution
The American alligator inhabits freshwater lakes, slow moving rivers, and brackish water habitats in Florida. The alligator can be found from southeast Oklahoma and east Texas, east to North Carolina, and down Florida (Florida distribution map data from: Krysko et al. 2011).
The main threat facing the American alligator is the destruction and degradation of its wetland habitat. Destruction of wetlands usually occurs in conjunction with human development. With increased development in their habitat, more alligators are removed at the request of the new property owners; these alligators are usually harvested when removed (University of Georgia, n.d.). Alligators are also vulnerable to increased predation. Alligator eggs face predation from raccoons, bears, and otters, and juveniles also face danger from wading birds and bigger alligators.
Conservation and Management
The American alligator is Federally protected by the Endangered Species Act as a Threatened species, due to their similarity of appearance to the American crocodile, and as a Federally-designated Threatened species by Florida’s Endangered and Threatened Species Rule .
Other Informative Links
Florida Museum of Natural History
FWC Species Profile
FWC Hunting Information
FWC Nuisance Alligator Program
International Union for Conservation of Nature
Smithsonian National Zoological Park
University of Georgia Savannah River Ecology Laboratory
U.S. Fish and Wildlife Service
Printable version of this page
Florida Museum of Natural History. (n.d.). Alligator mississippiensis (Daudin, 1801). Retrieved May 10, 2011, from: http://crocodilian.com/cnhc/csp_amis.htm
Krysko, K., K. Enge, and P. Moler. 2011.Alligator mississippiensis(Daudin 1801) American alligator. Atlas of Amphibians and Reptiles in Florida.
Smithsonian National Zoological Park. (n.d.). American Alligator. Retrieved 10 May , 2011, from Smithsonian National Zoological Park Friends of the National Zoo: http://nationalzoo.si.edu/Animals/ReptilesAmphibians/Facts/FactSheets/Americanalligator.cfm
University of Georgia . (n.d.). American Alligator (Alligator mississippiensis). Retrieved May 10, 2011, from Savannah River Ecology Laboratory: http://www.uga.edu/srelherp/alligators/allmis.htm
Image Credit Photo by FWC