Crocodiles are not native to Tennessee and are not found in the state’s natural environments. Tennessee’s climate and habitat conditions do not support the survival or breeding of true crocodile species. While large reptiles inhabit Tennessee, crocodiles are not naturally present.
Identifying Crocodilians
Distinguishing between crocodiles and alligators involves observing several physical characteristics. Alligators possess a broad, U-shaped snout, whereas crocodiles have a more pointed, V-shaped snout. Another key difference lies in their teeth: when an alligator’s mouth is closed, its lower teeth are generally hidden, fitting into sockets in the upper jaw. In contrast, a crocodile’s fourth lower tooth on each side remains visible, protruding outside the upper jaw even when its mouth is shut.
Alligators often appear darker, ranging from gray to black, which helps them blend into murky freshwater environments. Crocodiles tend to have lighter, olive or tan skin. Alligators primarily inhabit freshwater habitats, while many crocodile species are adapted to brackish or saltwater. True crocodiles are found throughout the tropics in Africa, Asia, the Americas, and Australia. American alligators are largely confined to the southeastern United States and parts of China.
Large Reptiles in Tennessee
American alligators are present in Tennessee, particularly in the state’s southwestern regions. These alligators are naturally expanding their range northward from southern states. Confirmed sightings have occurred in counties such as Shelby, Fayette, and Hardin, especially along the Mississippi River. Isolated sightings in other areas, including East Tennessee, often involve alligators likely raised in captivity and then released.
Alligators can survive Tennessee’s colder winters by entering a state of dormancy called brumation. During this period, they withstand freezing conditions by keeping their snouts above the water’s surface to breathe. Tennessee is also home to other large reptiles like snapping turtles. Both common snapping turtles and the larger alligator snapping turtles inhabit the state, with the latter primarily found in the western third. The state also supports over 30 species of snakes, including the Timber Rattlesnake and Gray Ratsnake, some growing to considerable lengths.
Environmental Factors Limiting Crocodiles
Crocodiles are ectothermic, meaning their body temperature is regulated by external heat sources like the sun. They require warm, tropical, or subtropical climates to thrive. Prolonged exposure to cold temperatures can be fatal. They depend on basking in the sun to warm up and seeking shade or water to cool down, maintaining a preferred body temperature around 30-33°C.
Crocodile habitat requirements include abundant water sources for hunting, refuge, and breeding, as well as suitable basking and nesting sites. While some species tolerate brackish or saltwater, many also inhabit freshwater environments. Tennessee’s climate, characterized by colder winters, is unsuitable for most crocodile species. The state’s predominantly freshwater systems and seasonal temperature fluctuations do not align with the consistent warm conditions necessary for their survival and reproduction.