Costa Rica is home to more than 200 species of reptiles, half of them snakes.

Crocodiles and Caimans

Many travelers visit Costa Rica in the hope of seeing American crocodiles and caimans, the croc’s diminutive cousins. Both species are easily seen in the wet lowlands. They are superbly adapted for water. Their eyes and nostrils are atop their heads for easy breathing and vision while otherwise entirely submerged, and their thick, muscular tails provide tremendous propulsion.

The American crocodile—one of four species of New World crocodiles—can easily be seen in dozens of rivers throughout the lowlands and estuaries along the Pacific coastline. Sections of the Tárcoles River have as many as 240 crocodiles per mile, far higher than anywhere else in Costa Rica. The creatures, which can live 80 years or more and reach six meters in length, spend much of their days basking on mudbanks, maintaining an even body temperature, which they regulate by opening their gaping mouths.

To the crocodile (cocodrilo), home is a “gator hole” or pond, a system of trails, and a cavelike den linked by a tunnel to the hole. The croc helps maintain the health of aquatic water systems by weaning out weak and large predatory fish.

Mating season begins in December. For all their beastly behavior, crocodiles are devoted parents. Eggs are laid March–May, during dry season. The mother will guard the nest and keep it moist for several months after laying. When they are ready to hatch, the hatchlings pipe squeakily and she uncovers the eggs and takes the babies into a special pouch inside her mouth. She then swims away, with the youngsters peering out between a palisade of teeth. The male assists, and soon the young crocs are feeding and playing in a special nursery, guarded by the two watchful parents (only 10 percent of newborn hatchlings survive).

Despite being relics from the age of the dinosaurs, croc brains are far more complex than those of other reptiles. They are sharp learners (in the Tempisque Basin, crocs have been seen whacking tree trunks with their tails to dislodge chicks from their nests). They also have an amazing immune system that can even defeat gangrene.

At night, they sink down into the warm waters of the river for the hunt. The American crocodile is generally a fish-eater, but adults are known to vary their diet with meat, even taking cattle carelessly taking a drink at the river’s edge…so watch out! Crocs cannot chew. They simply snap, tear, and swallow. Powerful stomach acids dissolve everything, including bones. A horrible way to go!

No more than two meters long, the spectacled caiman (guajipal locally) is still relatively common in parts of wet lowland Costa Rica on both the Atlantic and Pacific coasts. Palo Verde and Tortuguero are both good places to spot them in small creeks, playas, and brackish mangrove swamps, or basking on the banks of streams and ponds.

Caiman or croc? It’s easy to tell. The former is dark brown with darker bands around its tail and holds its head high when sunning. The much-larger crocodile is an olive color with black spots on its tail.

Iguanas and Lizards

The most common reptile you’ll see is the dragonlike tree-dwelling iguana, which can grow to a meter in length. You’ll spot them in all kinds of forest habitats, but particularly in drier areas below 760 meters elevation. There’s no mistaking this reptile for any other lizard. Its head is crested with a frightening wig of leathery spines, its heavy body encased in a scaly hide, deeply wrinkled around the sockets of its muscular legs. Despite its menacing One Million Years B.C. appearance, it is a nonbelligerent vegetarian.

There are two species in Costa Rica: the green and the spiny-tailed iguana. The green iguana (Iguana iguana), which is a dull olive color (adults) to bright green (juveniles), with a black-banded tail, can grow to two meters long. The males turn a bright orange when they get ready to mate in November or December and choose a lofty perch from which to advertise their prowess as potential lovers. Females nest in holes in the ground, then abandon their eggs. Male iguanas are territorial and defend their turf aggressively against competitors.

Campesinos, for reasons you may not wish to know, call the green iguana the “tree chicken.”

The smaller, gray or tan-colored spiny-tailed iguana, also called the ctenosaur (Iguana negra)—known locally as the garrobo—has a tail banded with rings of hard spines that it uses to guard against predators by blocking the entrance to holes in trees or the ground.

Another miniature dinosaur is Basilicus basilicus, or Jesus Christ lizard, a Pacific lowland dweller common in Santa Rosa, Palo Verde, and Corcovado National Parks. These use water as their means of escape, running across it on hind legs (hence their name)..”

To learn more, visit the website of the Green Iguana Foundation (www.iguanaverde.com).

Snakes

The 138 species of snakes make up more than half of all reptile species in the nation. Wherever you are in the country, snakes are sure to be about. They are reclusive, however, and it is a fortunate traveler indeed who gets to see in the wild the fantastically elongated chunk-headed snake, with its catlike elliptical eyes, or the slender, beak-nosed, bright green vine snake.

Among the more common snake species you are likely to see are the wide-ranging and relatively benign boas. Boas are aggressive when confronted: though not venomous, they are quite capable of inflicting serious damage with their large teeth.

Only 18 species of snakes in Costa Rica are venomous (nine are very venomous).

The coffee palm viper is a heat-seeking missile that can detect differences of 0.0003°C per meter! The small (yet potentially deadly) eyelash vipers are superbly camouflaged—yellow, green, mottled brown, gray, or chocolate to suit their environment—and often remain immobile for days on end, awaiting passing prey.

The all-black zopilota eats only other snakes and prefers the fearsome fer-de-lance (locally called terciopelo, Spanish for “velvet”), which is much feared for its aggressiveness and lethal venom—it accounts for 80 percent of all snakebites (and mortalities) in Costa Rica. One of several Central American pit vipers, the fer-de-lance can grow to a length of three meters and is abundant throughout the country except Nicoya, particularly in overgrown fields and river courses in drier lowland regions. Tiny juvenile fer-de-lance are just as deadly and are almost impossible to see as they rest in loose coils of black and brown on the forest floor. Give the fer-de-lance a wide berth! The fer-de-lance stands its ground and will bite with little provocation. Its equally large cousin, the bushmaster, is the most venomous of all vipers (humans suffer a 75 percent fatality rate if bitten), but it is relatively sheepish.

Among the more colorful snakes are the four species of coral snakes, with small heads, blunt tails, and bright bands of red, black, and yellow or white. These highly venomous snakes (often fatal to humans) exhibit a spectacular defensive display: They flatten their bodies and snap back and forth while swinging their heads side to side and coiling and waving their tails.

In the Pacific Ocean, you may sometimes encounter venomous pelagic sea snakes, yellow-bellied and black-backed serpents closely related to terrestrial cobras and coral snakes. This gregarious snake has developed an oarlike tail to paddle its way through the ocean. Its venom is among the most deadly toxins known to man, but they are known to have bitten humans only rarely.

Turtles

Six of the world’s eight species of marine turtles nest on Costa Rica’s beaches, and you can see turtles laying eggs somewhere in Costa Rica virtually any time of year.

Tortuguero National Park, in northeastern Costa Rica, is one of fewer than 30 places in the world that the green turtle considers clean enough and safe enough to lay its eggs. Although green turtles were once abundant throughout the Caribbean, today there are only three major sites in the region where they nest: one on Aves Island, 62 kilometers west of Montserrat, a second at Gandoca-Manzanillo, and the third on the endless beach between Tortuguero and Pacuare (the most important nesting site for leatherback turtles in Costa Rica).

On the Pacific coast, the most spectacular nestings are at Playa Nancite, in Santa Rosa National Park, and Ostional National Wildlife Refuge, and recently at Playa Camaronal, where tens of thousands of olive ridley turtles (lora) come ashore July–December in synchronized mass nestings known as arribadas. Giant leatherback turtles (baula) nest at Playa Grande, near Tamarindo, October–April and in lesser numbers at several other beaches. Hawksbills, ridleys, leatherbacks, Pacific greens, and occasionally loggerheads (primarily Caribbean nesters) appear in lesser numbers at other beaches along the Pacific coast.

Most of the important nesting sites in Costa Rica are now protected, and access to some is restricted. Turtle populations continue to decline because of illegal harvesting and environmental pressure, and all species are now critically endangered.

Despite legislation outlawing the taking of turtle eggs or disturbing nesting turtles, nest sites continue to be raided by humans (encouraged by an ancient Mayan legend that says the eggs are aphrodisiacs). Mother Nature, too, poses her own challenges. Coatis, dogs, raccoons, and peccaries dig up nest sites to get at the tasty eggs. Gulls and vultures pace the beach hungrily awaiting the hatchlings; crabs lie in wait for the tardy; and hungry jacks, barracudas, and sharks come close to shore for the feast. Of the hundreds of eggs laid by a female in one season, only a handful will survive to reach maturity.

Turtles have hit on a formula for outwitting their predators, or at least for surviving despite them. Each female turtle normally comes ashore two to six times each season and lays an average of 100 eggs on each occasion.

Most females make their clumsy climb up the beach and lay their eggs under the cover and cool of darkness (loggerheads and ridleys often nest in the daytime). They normally time their arrival to coincide with high tide, when they do not have to drag themselves puffing and panting across a wide expanse of beach. Some turtles even die of heart attacks brought on by the exertions of digging and laying.

Once she settles on a comfortable spot above the high-tide mark, the female scoops out a large body pit with her front flippers. Then her dexterous hind flippers go to work hollowing out a small egg chamber below her tail and into which white, spongy, golf-ball-size spheres fall every few seconds. After shoveling the sand back into place and flinging sand wildly about to hide her precious treasure, she makes her way back to sea.

The eggs normally take six to eight weeks to hatch, incubated by the warm sand. Some marvelous internal clock arranges for most eggs to hatch at night when hatchlings can make their frantic rush for the sea concealed by darkness. Often, baby turtles will emerge from the eggs during the day and wait beneath the surface of the beach until nightfall. They are programmed to travel fast across the beach to escape the hungry mouths. Even after reaching the sea they continue to swim frantically for several days—flippers paddling furiously—like clockwork toys.

No one knows where baby turtles go. They swim off and generally are not seen again until they appear years later as adults.

Turtles are great travelers capable of amazing feats of navigation. Greens, for example, navigate across up to 2,400 kilometers of open sea to return, like salmon, to the same nest site, guided presumably by stars and currents and their own internal compass.

When near nesting sites, respect the turtles’ need for peace and quiet. Nesting turtles are very timid and extremely sensitive to flashlights, sudden movements, and noise, which will send a female turtle in hasty retreat to the sea without laying her eggs. Sometimes she will drop her eggs on the sand in desperation, without digging a proper nest.

Freshwater turtles (jicoteas) are also common in Costa Rica, particularly in the Caribbean lowlands.