American Alligator

American Alligator: Alligator mississippiensis

Taxonomic Classification

Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Crocodila
Family: Alligatoridae
Genus/Species: Alligator mississippiensis
Common Name: American alligator

Listing Status

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)

Physical Description

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.

Life History

American Alligator Distribution Map 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).

Threats:

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 .

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References

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/Americanalligato r.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

American Alligator