It was established on 24 October 1975, and encompasses an area of 425 km˛ (263 mi˛).
It is widely considered the crown jewel in the extensive system of national parks and
biological reserves spread across the country. The ecological variety is quite stunning.
National Geographic has called it "the most biologically intense place on Earth".
Not only is the park very popular with tropical ecologists, a visitor can expect to see an abundance of wildlife.
This park conserves the largest primary forest on the American Pacific coastline and one of the
few remaining sizeable areas of lowland tropical rainforests in the world.
Corcovado supports a sizeable population of the endangered Baird's Tapir and it also
holds about 140 species of mammals (representing 10% of the mammal-species in America).
Costa Rica as a whole is an ornithologist's dream and Corcovado in particular holds over 400
bird species including Scarlet Macaws, Chestnut-mandibled Toucans, White Hawks, King Vultures, Turquoise and Yellow-billed Cotingas, and even
the endangered Harpy Eagle is still present here although sightings seldom happen. .
Large herds of White-lipped Peccaries roam the park as well as several big cats (including Jaguars, Ocelots, Cougars and Margay).
The abundance in wildlife can in part be explained by the variety of vegetation types, at least 13, including montane forest
(more than half the park), cloud forest, jolillo forest (palm swamp), prairie forest, alluvial plains forest, swamp forest,
freshwater herbaceous swamp and mangrove, which together hold over 500 tree species, including purple heart, poponjoche,
nargusta, banak, cow tree, mountain almond, espave and crabwood. Another reason for the diversity (as with all of Costa Rica) is that it
lies on a north-south corridor for flora and fauna; part of the "land bridge" and wildlife corridor that links the large
continents of North America and South America.
Caño Island National Park
This 300-hectare island rises 30 meters above the ocean's surface and is clearly visible from the western end of the Osa Peninsula, some 15 kilometers away. The distance was not an obstacle to the pre-Columbian peoples that inhabited the mainland and utilized the island as a burial site. Not only did they ferry their dead across this stretch of open water, but they also transported large spherical stones to the cemetery on top of the island. Some of these can still be seen today together with fragments of pottery and stoneware left behind by careless tomb robbers during the latter half of the 20th century.
The diversity of plant and animal species on Caņo Island pales in comparison to that of Corcovado National Park on the nearby mainland. For example, fewer than 60 species of trees and only 4 species of orchids are known to grow on the island. Likewise, there are just 4 species each of snakes, lizards, and frogs on the island, and only a dozen kinds of birds breed on this offshore sanctuary. This paucity of terrestrial flora and fauna results from the isolating effects of being an island.
However, where Caņo really comes into its own in terms of diversity is in its marine realm. The oceanic sector of the reserve protects 5,800 ha. of marine habitat surrounding the island. A mask, snorkel, and fins are all you need to appreciate the abundance and variety of aquatic life just below the surface. The beach in front of the ranger station is a good swimming beach and the submerged rocks on either side provide hours of snorkeling entertainment with such colorful fish as Moorish Idols, Blue Parrotfish, King Angelfish, Spotted Sharpnose Puffers, Barberfish, and Rainbow Wrasses. Scuba diving is also permitted at one or two sites.
Along the little stream that flows beside the ranger station you can get good looks at the so-called Jesus Christ Lizard doing its thing. More properly termed Lineated Basilisk Lizards, these brownish reptiles can't actually walk across water, but they do run across the surface, reared up on their hind legs so that the flaps of skin on their long toes spread out and function as miniature paddles. The little ones are best at executing this startling maneuver, but if you find a fully developed adult male with its head crest and dorsal fins, you will be looking at an awe-inspiring creature.
Sierpe River Mangroves
The largest stand of mangroves in Costa Rica is located in the delta region of the Sierpe and Terraba rivers, which
together form a continuous network of waterways through the mangroves. The mangroves and mudflats house many species
of water birds such as Northern Jacanas, Boat-billed Herons, Purple Gallinules, Black-bellied
Whistling-Ducks, Roseate Spoonbills, Whimbrels, White Ibis, and more. The endemic species Mangrove Hummingbird
and the endangered Yellow-billed Cotinga are also found here.
The importance of mangroves to the fishing industry is well known, since larval stages of shrimp and other juvenile marine creatures
are nurtured during their first weeks or months in the protection of mangrove tangles. Mudflats are extensive in some areas and many
herons and shorebirds may be observed feeding in the shallows. Large sections of this stand of vegetation are relatively undisturbed.
In this area, one passes through some of the most beautiful waterways to be found anywhere and we will travel on the Sierpe River as part of the journey to the Poor Man’s Paradise.