Reptiles

Reptilian tolerances for salt water and drought confer a superior potential over amphibians for crossing geographic barriers, but terrestrial and freshwater reptiles are still constrained by relatively small expanses of ocean. Only a few nonmarine reptiles (namely some lizards) have naturally invaded southern Florida from the tropics, probably by “rafting” on floating objects. Thus, nearly all native terrestrial and freshwater reptiles of the region came from the temperate land mass of North America, just as freshwater fishes and amphibians did. Like those groups, numerous tropical exotic reptiles have been introduced by man (see Chapter 22). Miami and other urban areas now harbor over a dozen exotic species of lizards from tropical parts of the world, and six exotic reptiles are established in Everglades National Park. The most notable is the huge Burmese python, escaped from the pet trade and now widely established. It has become a safety concern for humans and a major predator throughout the Everglades, including the coastal mangrove swamps.339,528

Representative reptiles of the Everglades region are listed in Table 18.1. All native terrestrial and freshwater species are allied to the temperate North American continent except for the green anole and the reef gecko. Marine/estuarine species, such as the American crocodile and marine turtles, are tropical. Because of the secretive habits of many reptiles, relatively few are commonly seen by Everglades visitors. The American alligator-a grand exception-is easily seen because of its lifestyle and large size, and certain large turtles, notably the Florida redbelly turtle (Figure 18.1) and the Florida softshell (Figure 18.2), are also commonly seen basking or swimming in the clear waters of the Everglades. Much less visible are the highly venomous eastern coral snake and its diminutive and harmless near-mimics, the scarlet kingsnake and the Florida scarlet snake. These particular snakes are uncommon and tend to be nocturnal, living underground ( fossorial habit) by day. Other reptiles, such as rattlesnakes, are difficult to see because of their cryptic color patterns. Rattlers have become much less common, but are still a consideration when hiking. The huge eastern diamondback (in 1966 the author observed a 7-foot specimen near Flamingo in Everglades National Park) is an obvious concern, but even the pygmy rattler-adults less than 2 feet long-can inflict a dangerous bite. The list contains three often-seen water snakes (freshwater members of the genus Nerodia) that are nonpoisonous but resemble the poisonous Florida cottonmouth, which has become much less common.