The Florida Keys are made up of a group of around 1,700 scattered islands, extending from about 15 miles south of Miami to 90 miles northeast of Cuba. Curving west, the Keys separate the Atlantic ocean from the Gulf of Mexico. The Keys have a subtropical climate and its shores, forests and inland wetlands provide rich habitats for snakes and other wildlife. Many of the 46 native snake species of South Florida live in the Keys, and now at least three non-native species also thrive there. You can identify and distinguish snakes by their size, the shapes of their heads and eyes, body form, color, color pattern and type of scales. The type of preferred snake habitat provides another clue.
Most venomous snakes can be distinguished from non-venomous snakes by the shape of their head and pupils. Venomous snakes also have fangs, whereas non-venomous snakes only have small teeth. The heads of venomous snakes are chunky, triangular or diamond-shaped. In contrast, non-venomous snakes have smooth, tapered heads. The pupils of venomous snakes are elliptical, or cat-like, while non-venomous snakes have round pupils.
Three of the venomous snakes inhabiting the Florida Keys, the eastern diamondback rattlesnake (Crotalus adamanteus), pygmy rattlesnake (Sistrurus miliarius) and cottonmouth or water moccasin (Agkistrodon piscivorus) are pit vipers. Pit vipers possess heat-sensitive facial pits underneath their eyes. The venom of these snakes destroys the red blood cells of their prey.
The large eastern diamondback rattlesnake with a rattle at the end of its tail lives in dry forested areas, whereas the small pygmy rattlesnake is encountered in a variety of habitats, including residential areas. The thick-bodied cottonmouth inhabits swamps and coastal marshes. The coral snake (Micrurus fulvius), which is not a pit viper, lives in dry habitats and hides underground or in leaf litter.
Common Non-Venomous Snakes
Although you may encounter the rough greensnake (Opheodrys aestivus) and ring-necked snake (Diadophis punctatus) in your garden or another residential area, they prefer forested places. The common kingsnake (Lampropeltis getula) also likes forested areas, but sometimes turns up in abandoned barns and houses.
Another commonly encountered snake is the black racer or blacksnake (Coluber constrictor). It likes to hang out in low shrubs with a nearby source of water. The common gartersnake (Thamnophis sirtalis) and the Florida green watersnake (Nerodia floridana) prefer open fresh water areas, such as ponds and marshes.
Snakes play an important role in the ecosystem, both as predators and prey. They are generally harmless to humans -- even venomous snakes will not attack unless stepped on or provoked. Snakes control insect pests and rodent populations, reducing overpopulation and rodent-transmitted diseases. However, the numbers of some snake species in the Florida Keys are dwindling. People are afraid of snakes and kill a large number each year. Another reason for the decline are road construction and development, leading to habitat fragmentation and loss.
The indigo snake (Drymarchon corais couperi) is listed as threatened: the designation is one step below the endangered status. Once abundant throughout Florida, this snake is hard to find now. It prefers a forested habitat near water.
The Florida brown snake (Storeria victa) and the Florida ribbon snake (Thamnophis sauritus sackeni) are only threatened in the lower Keys. Both of these snakes are found near bogs, ponds, marshes and pinelands.
Another threatened snake is the small rim rock crowned snake (Tantilla oolitica). It is a secretive snake, living in pine and hardwood areas that have sandy soil, or it hides under logs and debris.
Two other snakes in the Keys are not threatened but are of special concern. They are the Florida pine snake (Pituophis melanoleucus) and the red rat or corn snake (Elaphe guttatus or Pantherophis guttatus). The Florida ribbon snake is only of concern in the lower Keys. It is found in pine and swampy areas and sometimes shows up in residential places.
Introduced, invasive snakes threaten native species, ecosystems and, potentially, pets and people. At least three invasive snakes inhabit the Florida Keys: the Burmese python (Python molurus bivittatus), the common or red-tailed boa constrictor (Boa constrictor) and the Brahminy blind snake (Ramphotyphlops braminus). These snakes were introduced because of accidental or intentional releases of pet snakes.
The Burmese python is usually found in aquatic environments, such as marshes and swamps. The python eats anything from mice up to deer and even alligators.
The boa constrictor is commonly found in forested areas and eats mostly small animals.
The Brahminy blindsnake is so small that it is sometimes mistaken for an earthworm. All snakes are female and reproduce without a male counterpart. The snake is secretive and hides in soil and under logs or fallen leaves.
- Escape Florida Keys: Geography of the Florida Keys
- University of Florida Department of Wildlife Ecology & Conservation: South Florida's Snakes
- Florida Wildlife Control: About Florida's Venomous Snakes -- Identification & Bite Advice
- University of Florida Department of Wildlife Ecology & Conservation: Dealing with Snakes -- Is It Venomous?
- Florida Fish and Wildlife Conservation Commission: Florida's Nonvenomous Snakes
- Florida Fish and Wildlife Conservation Commission: Florida's Endangered and Threatened Species
- Florida Museum of Natural History: Florida Brown Snake
- Florida Museum of Natural History: Peninsula Ribbon Snake
- Florida Museum of Natural History: Eastern corn snake, Corn Snake, Chicken Snake, Red Rat Snake
- Fort Collins Science Center: Giant Constrictor Snakes in Florida: A Sizable Research Challenge
- Photo Credit Brand X Pictures/Stockbyte/Getty Images
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