American alligators (Alligator mississippiensis, hereafter called alligators, Figure 1), frequently called “gators,” are one of 22 crocodilian species worldwide and the most common crocodilians native to the US. The other native crocodilian species is the American crocodile (Crocodylus acutus). Caimans (Caiman spp.) are imported from Central and South America and survive and reproduce in Florida.
Alligators are federally classified as “threatened due to similarity of appearance” to other endangered crocodilians. The classification provides federal protection for alligators but allows state-approved programs for management and control. Alligators can legally be taken only by individuals with proper licenses or permits. Alabama, Florida, Louisiana, Georgia, South Carolina, and Texas have programs to control problem or nuisance alligators that allow hunters with permits to kill or facilitate the removal of alligators. Other states use state wildlife officials to remove alligators that are causing problems.
Alligators are distinguished from American crocodiles and caimans by a more rounded snout and black and yellow-white coloration. American crocodiles and caimans are olive-brown in color and have pointed snouts. Alligators and crocodiles are similar in physical size, while caimans are about 40% smaller. Male alligators can grow to more than 14 feet long and 1,000 pounds. Females can exceed 10 feet and 250 pounds. The growth rate of an alligator depends on diet, temperature, and sex. For example, to reach 6 feet in length, alligators take up to 10 years in Louisiana, 14 years in Florida, and 16 years in North Carolina. Alligators can reach a length of 6 feet in 3 years when they are raised on farms under ideal conditions.
Viable populations of alligators live in Texas, Oklahoma, Arkansas, Louisiana, Mississippi, Alabama, Florida, Georgia, South Carolina, and North Carolina (Figure 2). The northern range is limited by low temperatures in winter. Alligators rarely are found south of the Rio Grande River.
American crocodiles are scarce and protected in the US. They are found in the coastal waters of Florida, south of Tampa. Caimans rarely survive winters north of central Florida and reproduce only in southern Florida.
Voice and Sounds
Alligators communicate through bellows and slapping their heads.