Most visitors come to watch sea turtles lay eggs on the wild beaches. The area is more than just turtles, though: Tortuguero teems with wildlife. You’ll find sloths and howler monkeys in the treetops, tiny frogs and green iguanas scurrying among buttress roots, plus mighty tarpons, alligators and endangered manatees swimming in the waters.

Turtle-Watching

The area attracts four of the world’s eight species of sea turtle, making it a crucial habitat for these massive reptiles. It will come as little surprise, then, that these hatching grounds gave birth to the sea-turtle-conservation movement. The Caribbean Conservation Corporation, the first program of its kind in the world, has continuously monitored turtle populations here since 1955. Today green sea turtles are increasing in numbers along this coast, but the leatherback, hawksbill and loggerhead are in decline.

Most female turtles share a nesting instinct that drives them to return to the beach of their birth (their natal beach) in order to lay their eggs. (Only the leatherback returns to a more general region instead of a specific beach.) During their lifetimes, they will usually nest every two to three years and, depending on the species, may come ashore to lay eggs 10 times in one season. Often, a turtle’s ability to reproduce depends on the ecological health of this original habitat.

The female turtle digs a perfect cylindrical cavity in the sand using her flippers, and then lays 80 to 120 eggs. She diligently covers the nest with sand to protect the eggs, and she may even create a false nest in another location in an attempt to confuse predators. She then makes her way back to sea – after which the eggs are on their own. Incubation ranges from 45 to 70 days, after which hatchlings – no bigger than the size of your palm – break out of their shells using a caruncle, a temporary tooth. They crawl to the ocean in small groups, moving as quickly as possible to avoid dehydration and predators. Once they reach the surf, they must swim for at least 24 hours to get to deeper water, away from land-based predators.

Because of the sensitive nature of the habitat and the critically endangered status of some species, tours to see this activity are highly regulated. It is important not to alarm turtles as they come to shore (a frightened turtle will return to the ocean and dump her eggs). In high season, tour groups gather in shelter sites close to the beach and a spotter relays a turtle’s location via radio once she has safely crossed the high-tide mark and built her nest. At this time, visitors can then go to the beach and watch the turtle lay her eggs, cover her nest and return to the ocean. Seeing a turtle is not guaranteed, but licensed guides will still make your tour worthwhile with the wealth of turtle information they'll share. By law, tours can only take place between 8am and midnight. Some guides will offer tours after midnight; these are illegal.

Visitors should wear closed-toe shoes and rain gear. Tours cost US$25. Nesting season runs from March to October, with July and August being prime time. The next best time is April, when leatherback turtles nest in small numbers. Flashlights and cameras are not allowed on the beach. Wear nonreflective, dark clothing.

Other Wildlife-Watching

More than 400 bird species, both resident and migratory, have been recorded in Tortuguero – it's a birdwatchers' paradise. Due to the wet habitat, the park is especially rich in waders, including egrets, jacanas and 14 types of heron, as well as species such as kingfishers, toucans and the great curassow (a type of jungle peacock known locally as the pavón). The great green macaw is a highlight, most common from December to April, when the almond trees are fruiting. In September and October, look for flocks of migratory species such as eastern kingbirds, barn swallows and purple martins. The Sea Turtle Conservancy conducts a biannual monitoring program in which volunteers can help scientists take inventory of local and migratory species.

Certain species of mammal are particularly evident in Tortuguero, especially mantled howler monkeys, the Central American spider monkey and the white-faced capuchin. If you’ve got a reliable pair of binoculars and a good guide, you can usually see both two- and three-toed sloths. In addition, normally shy neotropical river otters are reasonably habituated to boats. Harder to spot are timid West Indian manatees and dolphins, which swim into the brackish canals looking for food. The park is also home to big cats such as jaguars and ocelots, but these are savvy, nocturnal animals – sightings are very rare.

Most wildlife-watching tours are done by boat. To get the best from Tortuguero, be on the water early or go out following a heavy rain, when all the wildlife comes out to sunbathe. It is also highly recommended to take tours by canoe or kayak – these smaller, silent craft will allow you to get into the park’s less trafficked nooks and crannies.

Boating

Four aquatic trails wind their way through Parque Nacional Tortuguero, inviting waterborne exploration. Río Tortuguero acts as the entranceway to the network of trails. This wide, beautiful river is often covered with water lilies and is frequented by aquatic birds such as herons, kingfishers and anhingas – the latter of which is known as the snakebird for the way its slim, winding neck pokes out of the water when it swims.

Caño Chiquero and Canõ Mora are two narrower waterways with good wildlife-spotting opportunities. According to park regulations, only kayaks, canoes and silent electric boats are allowed in these areas. Caño Chiquero is thick with vegetation, especially red guácimo trees and epiphytes. Black turtles and green iguanas like to hang out here. Caño Mora is about 3km long but only 10m wide, so it feels as if it’s straight out of The Jungle Book. Caño Haroldas is actually an artificially constructed canal, but that doesn’t stop the creatures – such as Jesus Christ lizards and caimans – from inhabiting its tranquil waters.

Canoe rental and boat tours are available in Tortuguero village.

Hiking

Behind Cuatro Esquinas ranger station, the well-trodden main trail is a muddy, 2km out-and-back hike that traverses the tropical humid forest and parallels a stretch of beach. Green parrots and several species of monkey are commonly sighted here. The short trail is well marked. Rubber boots are required and can be rented at hotels and near the park entrance.

A second hiking option, Cerro Tortuguero Trail, is also available. To reach the trailhead, guests have to take a boat to the town of San Francisco, north of Tortuguero village, where they will disembark at another ranger station and buy a ticket (US$7, plus US$4 for the 15- to 20-minute round-trip boat ride). The trail then takes visitors 1.8km up a hill for a view of the surrounding lagoon, forest and ocean. Casa Marbella in Tortuguero village can help guests organize the details and even arrange a local guide (from US$35) to take you on the trip.