Peninsula de Osa, Costa Rica
During our dreams, Sea Voyager followed the coast south from Manuel Antonio to anchor in the sheltered islet of Drake Bay on the northern face of the Peninsula de Osa. We are not the first explorers here. By 15,000 years BP, Amerindians began exploiting the sweet waters of the Rio Aguja, as well the microhabitat and resource-rich nexus of littoral zone and riverine, mangrove and wet lowland forests. Francis Drake landed at Drake Bay 501 years ago during his circumnavigation of the world. In addition to the availability of resources to refill empty ships and famished sailors for the, Drake used Drake Bay as safe haven from the wrath of Colonial Spain in 1597; he returned on numerous occasions in coming decades. The Spanish court despised Drake as a marauding pirate of their transoceanic fleets laden gold, booty and supplies. Queen Elizabeth I, saw Drake as her and England’s victorious champion in the centuries-long battles between England and Spain for control of the New World’s wealth and peoples.
This morning we followed the Amerindian and colonial pathways using kayaks and Zodiacs as we explored the Rio Agujas. The richness of the habitat was attested by the abundance of fruiting and flowering trees, birds, caiman, fish, and the calls of distant howler and spider monkeys startled and momentarily protesting our benign intrusion. As we lunched, our ship took us to Estacion San Pedrillo, the northern outpost guarding Corcovado National Park. Several of our party chose to linger at simple and comfortable estacion, for a nap; another took a novel to the shade of a clump of coconut trees.
Most set off on the well maintained trail through the old growth forest along the river banks, one kilometer to the north of the park station. Almost immediately, we spotted a crocodile sunning on a sandbank. We watched spider monkeys feed on the fruits of Cupania cineria (Sapindaceae). Then a twiney section of Passiflora nitida vine was detected, giving us the opportunity to inspect the faux mimics of Heliconius butterflies eggs evolved by this passion flower vine to deceive and deter female Heliconius butterflies laying additional eggs. The first caterpillar to hatch will cannibalize any other butterfly eggs encountered; late arriving females and their eggs pay a heavy price.
Trees became bigger and older and the density of undergrowth decreased as our trail took us farther from the beach. Within one-quarter kilometer, our trail entered old growth. Neotropical wet lowland forests, however, have many karmas, or as usually described, many disparities in forest composition and structure. Although the forest was dense with thick-boled canopy trees, a mere three tree taxa accounted for the large majority of the forest: Caryocar costaricense (Caryocaraceae;); Symphonia globulifera, (Clusiaceae); and Brosimum utile (Moraceae). Except at the river mouth, palms, such as Astrocaryum and Bactris, were uncommonly scarce. One outstanding commonality binds these disparate taxa. All three trees provide the raw materials for foods, medicines, transport, housing, tools, clothing of widely demonstrated critical importance to pre-Columbian Amerindians. Caryoar, to mention a small sample of Amerindian ingenuity, yields rich crops of tasty nut meats about the size of small chicken eggs. Early ethnographic reports of Amerindian tribes in South American abundantly document that appropriately processed Caryocar bark provided cloth used skirts for women and breechclouts for men. The thick fibrous, bark was also a valued for making canoes in manner analogous to the birch bark canoes of northern North America.
Once reaching our objective, our unanimous attention fixed on the multi-tiered, waterfall with a drop of about 80-90 m. The waters gush and crash and none of us can recall encountering greater air turbulence apart from encounters with hurricanes and tornados. A cloud of mist filled the gully. Intensely glowing through the fog, a shrubby tree burned fiercely on a stone outcrop. We witnessed a phenomenon rarely seen by transient travelers in Pacific the wet lowland rainforests of Costa Rica: an Erythrina costaricense (Papilionoideace) treelet in full flower. Fireworks of vivid scarlet compound flowers were showered on the scruffy, seemingly dead branches. Erythrina costaricense is one of the rare Neotropical trees dropping leaves throughout the wet season, with new foliage emerging after the fruit is set. Hummingbirds are presumed pollinators, but this is yet to be documented. We celebrated our delight by adjourning to an inviting waterhole until rising tides demanded we return to the beach and our awaiting Zodiacs.
