When you think of reptiles you typically think of tropical rainforest or the desert. However, there is at least one member of the three orders of reptiles that do live in the sea. Saltwater crocodiles are found in the Indo-Pacific region as are about 50 species of sea snakes. There is one marine lizard, the marine iguana of the Galapagos Islands, and then the marine (or sea) turtles. These are found worldwide and are the only true marine reptiles found in the Gulf of Mexico.
Sea turtles are very charismatic animals and beloved by many. Five of the seven species are found in the Gulf. These include the Loggerhead, which is the most common, the Green, the Hawksbill, the Leatherback, and the rarest of all – the Kemp’s Ridley.
Many in our area are very familiar with the nesting behavior of these long-ranged animals. They do have strong site fidelity and navigate across the Gulf, or from more afar, to their nesting beaches – many here in the Pensacola Beach area. The males and females court and mate just offshore in early spring. The females then approach the beach after dark to lay about 100 eggs in a deep hole. She then returns the to the Gulf never to see her offspring. Many females will lay more than one clutch in a season.
The eggs incubate for 60-70 days and their temperature determines whether they will be male or female, warmer eggs become females. The hatchlings hatch beneath the sand and begin to dig out. If they detect problems, such as warm sand (we believe meaning daylight hours) or vibrations (we believe meaning predators) they will remain suspended until those potential threats are no more. The “run” (all hatchlings at once) usually occurs under the cover of darkness to avoid predators. The hatchlings scramble towards the Gulf finding their way by light reflecting off the water. Ghost crabs, fox, raccoon, and other predators take almost 90% of them, and the 10% who do reach the Gulf still have predatory birds and fish to deal with. Those who make it past this gauntlet head for the Sargassum weed offshore to begin their lives.
These are large animals, some reaching 1000 pounds, but most are in the 300-400 pound range, and long lived, some reaching 100 years. It takes many years to become sexually mature and typically long-lived / low reproductive animals are targets for population issues when disasters or threats arise. Many creatures eat the small hatchings, but there are few predators on the large reproducing adults. However, in recent years humans have played a role in the decline of the adult population and all five species are now listed as either threatened or endangered and are protected in the U.S. There are a couple of local ordinances developed to adhere to federal law requiring protection. One is the turtle friendly lighting ordinance, which is enforced during nesting season (May 1 – Oct 31), and the Leave No Trace ordinance requiring all chairs, tents, etc. to be removed from the beach during the evening hours. There are other things that locals can do to help protect these animals such as: fill in holes dug on the beach during the day, discard trash and plastic in proper receptacles, avoid snagging with fishing line and (if so) properly remove, and watch when boating offshore to avoid collisions.
If we include the barrier islands there are more coastal reptiles beyond the sea turtles. There are freshwater ponds which can harbor a variety of freshwater turtles. I have personally seen cooters, sliders, and even a snapping turtle on Pensacola Beach. Many coastal islands harbor the terrestrial gopher tortoise and wooded areas could harbor the box turtles. In the salt marsh you may find the only brackish water turtle in the U.S., the diamondback terrapin. These turtles do nest on our beaches and are unique to see. Freshwater turtle reproductive cycles are very similar to sea turtles, albeit most nest during daylight hours.
The American alligator can also be found in freshwater ponds, and even swimming in saltwater. They can reach lengths of 12 feet, though there are records of 15 footers. These animals actually do not like encounters with humans and will do their best to avoid us. Problems begin when they are fed and loose that fear. I have witnessed locals in Louisiana feeding alligators, but it is a felony in Florida. Males will “bello” in the spring to attract females and ward off competing males. Females will lay eggs in a nest made of vegetation near the shoreline and guard these, and the hatchlings, during and after birth. They can be dangerous at this time and people should avoid getting near.
We have several native species of lizards that call the islands home. The six-lined race runners and the green anole to name two. However, non-native and invasive lizards are on the increase. It is believed there are actually more non-native and invasive lizards in Florida than native ones. The Argentina Tegu and the Cuban Anole are both problems and the Brown Anole is now established in Gulf Breeze, East Hill, and Perdido Key – probably other locations as well. Growing up I routinely find the horned lizard in our area. I was not aware then they were non-native, but by the 1970s you could only find them on our barrier islands, and today sightings are rare.
Then there are the snakes.
Like all reptiles, snakes like dry xeric environments like barrier islands. We have 46 species in the state of Florida, and many can be found near the coast. Though we have no sea snakes in the Gulf, all of our coastal snakes are excellent swimmers and have been seen swimming to the barrier islands. Of most concern to residents are the venomous ones. There are six venomous snakes in our area and four of them can be found on barrier islands. These include the Eastern Diamondback Rattlesnake, the Pygmy Rattlesnake, the Eastern Coral Snake, and the Eastern Cottonmouth. There has been a recent surge in cottonmouth encounters on islands and this could be due to more people with more development causing more encounters, or there may be an increase in their populations. Cottonmouths are more common in wet areas and usually want to be near freshwater. Current surveys are trying to determine how frequently encounters do occur.
Not everyone agrees, but I think reptiles are fascinating animals and a unique part of the Gulf biosphere. We hope others will appreciate them more and learn to live with and enjoy them.