Tortuguero National Park

Habitat
This marine turtle migrates along routes crossing between tropical and subtropical waters; occasionally it will venture into cooler northern waters. The turtle requires tropical beaches for nesting.

Range
With Atlantic and Pacific Ocean populations and multiple migratory tracts, the green turtle is found in open water and along the coasts of many countries (while widespread, the turtle’s numbers are still in danger). Its range includes the waters between Papua New Guinea, the Galapagos and Hawaiian islands, Mexico, Panama, Colombia, Venezuela, Chile, Argentina, South Africa, and New Zealand. It may stray as far north as Alaska, Canada, Europe, or Japan.

Physical Description
The large, brown marine reptile was named the green turtle because its body fat has a greenish hue. The underside of the turtle (the plastron) is a yellowish white or cream color. The exposed body parts have grayish skin. The wide, heart-shaped shell (carapace) may have some olive or dark colorings and wavy line markings. Juveniles look different: the shell is a darker blue-black and the underside is a brighter white with a dark band down each side of the body.

Males have one claw at the end of each front flipper as well as a long tail that reaches beyond the shell edge; these help him hold onto the female during mating. A female’s tail is shorter and does not extend past the edge of her shell.

This turtle sometimes resembles the hawksbill turtle; counting scales or scutes can help distinguish these two, but more simply Chelonia mydas has an elongate, rounded head that is not narrow like the hawksbill and does not end in a hooked bill. The green turtle’s Atlantic Ocean presence carries a separate migration route from the populations in the Pacific Ocean. Those in the Pacific tend to be smaller and darker.

Biology and Natural History
Every 2 to 4 years, a female green turtle will join the large offshore aggregations of adults who come to breed. In the shallow waters, males and females approach each other and the male fixes himself above the female by holding on with his hooked front flippers and prehensile tail. Some aggressive males may try to dislodge another male from his position, and occasionally two or even three males will clamor in an awkward stack on top of one female.

After mating, a female may come onshore once every few days to lay another clutch of eggs; she may make up to 7 of these trips, although most only do so 2 or 3 times. She will use her front flippers to scoop out a deep hole, then carefully deposit about 100 fragile, leathery-shelled eggs resembling ping pong balls, and finally covers the eggs in sand. Turtles develop according to temperature-dependent sex determination. This means that if the temperature of the egg is lower than 28.5oC, that turtle will become a male; if the temperature is greater than 30.3oC, it will be a female. That is, if the turtle makes it to hatching. Humans, dogs, raccoons, and other animals dig up nests. After several weeks the eggs hatch into tiny turtles which scramble to the surface and towards the ocean. Gulls, frigatebirds, and crabs ambush the turtles as they cross the expanse of beach to the water, where predatory fish wait for the new arrivals. However, while clumsy and slow on land, green turtles are nimble swimmers and seem to take on a different body underwater.

The first year of the green turtle’s life is not well understood. They are vulnerable in this smaller stage and eaten by many predators. The sea turtle’s main protection is hefty size and hearty shell—and infant turtles have neither yet. Few survive their first year. They may spend this time among sargassum rafts in the ocean until they reach about 0.5 kg in weight, when they return to shallower waters to feed and continue growing. Once a turtle weighs about 40 kg, it begins eating and spending more of its daily energy around floating grass flats. At 10 to 15 years of age and a mature size of 60 kg, a green turtle will begin its breeding pattern and continue for the rest of its life. At this size, the turtle is not vulnerable. Its only natural predators are large sharks.

Key aspects of the green turtle’s life cycle are still largely mysterious. Their migration patterns and behavior are difficult to trace and interpret, as are factors of sexual maturity, courtship, and ecology, making it harder for biologists to devise ways to help these vanishing sea giants. Like most marine turtles, the green turtle has suffered heavy losses from poaching for eggs, meat, and shell souvenirs. Nets of commercial shrimp fishermen and others drown pregnant females. Rising climate due to global warming is affecting sensitive egg development. Ever popular beachfront development continues to spread on and destroy fragile beach nesting sites and contribute light and noise pollution which can scare off or confuse nesting females and new hatchlings.

Tours to nesting sites are popular; some are legitimate and careful. It is important to strictly follow behavioral requirements when visiting turtle nesting beaches, particularly being quiet and not using any lights or camera flashes. Eating turtle eggs or meat dishes or buying souvenirs or products made from turtles is directly harmful to the existence of the species and unethical. Sea turtles naturally have a low survival rate and take many years to reach sexual maturity. Continuing to add human pressures to their populations may prove fatal to these graceful mysteries. Preserving their beaches and respecting their space both on land and in water is necessary for their survival.

Diet
Young green turtles are predatory, but mature ones are herbivorous, mainly grazing on shallow water sea grass pastures. Turtle grass (Thalassia testudinum) is the main course, but the turtle will consume other sea grasses or algae at times.

Height/Weight
Adults weigh 100-200 kg but can reach over 300 kg. Carapace (shell) length is usually between 90 and 150 cm long and can be over 1 m wide.

Taxonomy
Order: Testudines
Family: Cheloniidae

Habitat
This toucan is common from sea level to 1,200 m in forest, tall second growth, and pastures that contain some mature trees.

Range
The Keel-Billed lives between southern Mexico and northern Colombia and northwestern Venezuela.

Physical Description
The Keel-Billed Toucan is sometimes called the Rainbow-Billed Toucan, for the progression of yellow, orange, lime, and pale blue to the crimson tip of its exceptionally bright and enormous beak. This bill is deceptively light-being hollow and narrow-and a surprisingly adroit tool for plucking ripened fruits from awkward angles without trusting this large bird's weight to flimsy branches. The bill, white tail feathers, and bright blue legs contrast with the rest of the dark bird. Aside from yellow facial skin and bib lined in red, this large bird's body is mostly black with maroon on its back and neck, and olive on its lower back and underside.

Interesting Biology
In small flocks of up to 6 birds, the Keel-Billed Toucan travels through the upper levels of closed-canopy forest and nearby tall secondary forest. They may also forage in areas that are semi-open or along edges as they look lower for berries. They can be seen tossing their heads backwards to drop food from the end of the long bill into the throat. Choruses that sound like frogs may be sung while in their flocks; individually, the toucan may croak or call in a wooden or metallic tone, or sing a series of shrill chirps that resounds like a cricket. The toucan nests deep within tree cavities that have hollowed out from decay. They may move into holes that are 2.7 to 27 m off the forest floor, and do not bother lining the nest with anything besides regurgitated seeds.

Diet
This omnivorous bird sustains itself on fruits, including those with large seeds (such as Cirola or Protium), small seeded berries, or Cecropia catkins. To diversify its diet, the toucan also eats insects, spiders, small lizard and snakes, and the eggs and nestlings of small bird species.

Height/Weight
Male Keel-Billed Toucans reach 47 cm in length and 500 g; females are smaller, at 44 cm and 380 g.

Brief Taxonomy
Order: Piciformes
Family: Ramphastidae

Habitat
Howlers live in the canopies of lowland and montane forests.

Range
This primate lives up to an elevation of 2,500 m from southern Mexico to northwestern South America.

Physical Description
Adults are black with brown or blonde saddles; infants are silver to golden brown and become increasingly like adult coloration until they are about 12 weeks old.

Biology and Natural History
Howlers are famous for the incredible vocalizations made by adult males. Their howls can be heard more than 1 km away through the forest. They often make calls at sunrise and sunset or in response to people, airplanes, rain and thunder, or other howlers. Some biologists conclude that the howling is used as a spacing mechanism between individuals or to communicate within the troop.

The group is usually defined as several adult males and females, with their juveniles and infants, although juveniles usually leave their parents' group eventually. At 12 weeks old, howlers may move away from their parents. A female will become sexually active at 3 years, and have her first infant before her fourth year, with a gestation period of 6 months. Within a group, all adult males are dominant to all adult females, but the youngest adult of either sex holds the alpha rank for that sex. Average group size varies from 11 to 18 depending on the region. Howlers hardly ever descend to the ground except to travel between islands of trees in a habitat.

Diet
These primates are sedentary foragers: they eat mostly leaves, but they may also pick fruits and flowers. Since they are not dependent on only eating fruit (as spider monkeys do), howlers can survive in daily and home ranges rather small for a primate of their size. They are very choosy eaters, and often only eat certain parts of an individual tree and other parts of a different tree. From one tree they may choose mature leaves, young leaves, flowers, the petioles or the pulvinus of leaves. They also seem to base their food choices on how much the plant contains protein, fiber, and levels of alkaloids and tannins. Essentially, they try to maximize protein and amino acids in their diet but minimize their intake of fiber and plant secondary compounds.

Height/Weight
An adult male howler can weigh up to 6 to 7 kg; an adult female will generally be 4 to 5 kg. Howlers have tails longer than their head and body length. Infant howlers are about 0.4 kg at birth.

Taxonomy
Order: Primates
Family: Cebidae

Habitat

This large frugivore lives in the canopy of lowland and highland wet forests.

Range

The total range for this bird includes the area between eastern Honduras and northern Colombia.

Physical Description/Interesting Biology

The largest toucan in Central America, the Chestnut-mandibled Toucan, is a prominent member of its habitat. These large, brightly marked birds call to each other in piercing tones, especially in the morning, and small flocks can create a boisterous commotion from their conspicuous perches. Groups of about 20 will travel together through and forage in the canopy, semi-open areas, or clearings with remaining tall trees. Closer to nightfall, flocks congregate at tall emergent trees or tall dead snags and call together.

Aside from the male's larger size, the two sexes look alike: a black body bibbed in bright yellow, a white rump, and red on the underside of its tail feathers. The distinctly shaped and bicolor bill is brown and yellow, huge and curved. Although the Chestnut-mandibled Toucan may appear similar to the Keel-billed Toucan, the Chestnut-mandibled has a deeper yellow bib, is somewhat larger, and dominates the Keel-billed at fruiting trees. Toucans have large bills that are hollow, lightweight, and dexterous, enabling the birds to snatch fruit or prey without hazarding a leap onto branches too small for the toucan's weight.

Bright plumage in birds is often related to courtship or territorial behaviors, but copulation for these birds notably lacks any sort of display, precursor, or ritual, and the entire process lasts less than 5 seconds. The mating pair, however, stays together for the season, and forage and parent together. They make their nest in tree cavities in living or dead trees, or in old woodpecker holes for 2 to 3 eggs, and raise the chicks together.

A male will also feed his mate fruit, and they will preen each other. Even after breeding stops, a male will allow only his mate to forage in "his' section of a fruiting tree. Their foraging cooperation is more extensive: often a male arrives first at a tree, and the female follows him soon thereafter; he leaves before all the fruit is eaten, and she finishes it while he moves to the next tree. This strategy of dominating two trees at once helps both of them gain more food, because most other birds leave toucans arrive. The Chestnut-mandibled may also chase the Keel-billed Toucan out of water-filled hollows that they use for bathing and drinking.

This toucan has an important ecological role as a seed disperser for certain trees such as Virola; if, however, an individual tree produces many fruits at once, the toucan may stay nearby and eat a lot from it, and does not disperse the seeds. The Chestnut-mandibled Toucan is usually visible in the canopy, but sometimes needs to search through the understory or on the forest floor for small animals to round out their diet.

Diet

This toucan eats a variety of fruit, including different seeds, berries, drupes, arilloids, and fruit fleshes. They will also take insects or small snakes, and hunt for birds' eggs, nestlings, and lizards.

Height/Weight

Adult females are generally 52 cm long and weigh 580 g; males are 56 cm and weigh 750 g.

Brief Taxonomy

Order: Piciformes
Family: Ramphastidae

Habitat
The hawksbill prefers shallow coastal waters and is frequently found around underwater rocks and coral reefs. Sometimes they are seen in estuaries.

Range
This turtle lives in the warm tropical and subtropical waters of the Pacific, Atlantic, and Indian oceans as well as the Caribbean Sea.

Physical Description
The hawksbill is distinct among the sea turtles. It has a beaklike mouth that is curved and sharp, helping the turtle protect itself and eat. This is the only turtle with overlapping scutes (plates) on its shell. The shell is heart-shaped or shield-shaped; the edge becomes serrated toward the rear of the body. The hawksbill also has two pairs of large scales on its head between the eyes. Finally, and importantly, this turtle has an iridescent brown and cream pattern on its back popularly known as "tortoiseshell."?

Both sexes of this species have brown to reddish-brown scales on their skin that are bordered with yellow. The plastron, or underside, is yellow. The female's plastron is flat, but the male has a plastron that curves inward. This helps the male hold onto the female better when they mate, because her shell curves out. The male also has a long tail that can help him hold on.

Biology and Natural History
Dangerous as it is delicate, the hawksbill can and does defend itself with its large, hooked upper jaw. This is one of the most aggressive sea turtles.

Males and females meet in the shallow waters offshore of nesting beaches between April and November, with the highest activity in June or July. But these turtles mate when the female is returning to sea after laying her eggs, so their coupling is for a future season. Unlike the green turtle and olive ridley, the hawksbill is an individual nester. A female comes to nest once every three years, and she lays multiple clutches of eggs. At night, she crawls ashore, digs a chamber in the sand with her hind flippers, and releases between 50 and 200 eggs. She then pushes sand back over the eggs and heads back to the surf. Her eggs will hatch after 8 or 9 weeks, and the young turtles will begin racing to the water.

This turtle's diet makes it poisonous to humans (see below), but the hawksbill has still been overhunted for a long time. The hawksbill's shell, uniquely patterned and considered fashionable in some places, made the turtle a target for hunters. The shells were used for combs, jewelry, and other trinkets at the cost of heavily endangering the irreplaceable hawksbill. Now tortoiseshell patterns are manufactured so there should not be demand for the turtle's body. Still, poachers kill these turtles for their shells, meat, and eggs.

The hawksbill is a critically endangered species. It is protected by international policies and illegal to hunt. Read about Sea Turtles: Promises and Threats to learn more about the challenges facing this animal.

Diet
As a younger turtle, the hawksbill eats both plants and prey, but as it matures it eats more meat, including fish, mollusks, and sponges. It is able to eat jellyfish, and even eats the dangerously poisonous Portuguese man-of-war. Toxins from the jellyfish and sponges that the turtle eats make it a dangerous meal for humans, even though some still sell it as food. As long as people keep buying turtle eggs, meat, or shells, the fate of these delicate creatures is at great risk.

Height/Weight
At its largest, the hawksbill can reach almost 100 cm in length.

Taxonomy
Order: Testudines
Family: Cheloniidae

Habitat
This sea turtle is often spotted swimming in coral reefs and shipwrecks.

Range
The loggerhead is found among tropical and subtropical regions in the Pacific, Atlantic, and Indian oceans.

Physical Description
This is the largest sea turtle in the world with a hard shell. As big as it is today, in the past it reached gigantic sizes (see below). The loggerhead's immensity is surpassed only by the soft-shelled leatherback sea turtle.

The loggerhead's carapace (or shell) is a reddish to brown color; the upper sides of its head and flippers are similarly chestnut-brown to dark brown, with light yellow to tan borders on the limbs and underside. On the head and face of the turtle, the scales can be pale yellow around dark brown centers.

This sea turtle's shell is heart-shaped and elongate, and the edge is serrated towards the rear. It has at least five scutes (plates) on each side of the center row. A juvenile will have three long ridges on the shell that become smooth as it reaches adulthood. A female's tail only reaches the edge of the shell, but a male's longer tail noticeably extends past the shell.

Biology and Natural History
Female loggerheads born in temperate regions return to breed in those places in the summer. As females revisit their nesting beaches, males meet them and mate in the water for three or more hours. At night, a female comes on land to dig a nest. She deposits between 60 and 200 eggs and may lay more clutches 12 to 15 days apart. The temperature of the sand while the eggs are incubating affects the sex of the hatchlings as well as how long they take to develop, but most take 7 to 10 weeks before they hatch.

There is a great need to know more about how juvenile turtles develop once they leave the nest and reach the sea. Those that make it past a year old can be spotted in coastal waters, such as on floating mats of seaweed.

The eggs of the loggerhead are highly demanded because of the popular lie that turtle eggs can cure impotency or serve as an aphrodisiac, even though they cannot. The loggerhead is still overhunted.

The loggerhead is an endangered species. It is protected by international policies and illegal to hunt. Read about Sea Turtles: Promises and Threats to learn more about the challenges facing this animal.

Diet
The great size and strength of the loggerhead's head enables it to eat a lot of smaller sea creatures, including crab, shrimp, mollusks, squid, and jellyfish. Algae and other plants have been found in loggerhead stomachs"”these could be intentional foods, or gobbled up along with the turtle's prey.

Height/Weight
Today, most adults are between 80 and 120 cm. The loggerhead is capable of reaching enormous sizes, but today loggerheads are killed by poachers or drown in nets of fishermen before they get that huge. The largest loggerhead recorded was 230 cm (or 90.5 in) and could have weighed 340 kg (or 1,190 lbs).

Taxonomy
Order: Testudines
Family: Cheloniidae