Birds of the Costa Rica Trip

The species count for our 12-day trip was 58, a modest total for this birders' paradise. Stiles and Skutch in their guide book, Birds of Costa Rica (1989), report 830 species in an area the size of West Virginia. That is more than are found in all of the United States and Canada combined. The overlapping of South and North American species accounts for some of the diversity, as does the wide variety of habitats. Two coastal plains divided by a chain of mountains running northwest to southeast provide ample opportunities for species differentiation.

Eylen Zuñiga, one of the Ecology Project International biologists who organized our trip, accompanied me on several bird walks around the Pacuare biology station and the lowland rain forest at La Suerte, Limón. Spotting birds in dense jungle vegetation is difficult and requires patience and luck. It is kind of like fishing in that a quiet approach, and a good insect repellant, are key. Pedro Freitas was the only student willing to brave the clouds of moskitoes and join us on our strolls through the rain forest.

One of the best sightings during the trip was the female White-collared Manakin (Manacus candei) pictured above. She had built a chest-high nest in an open shrub behind our bunkhouse and in front of the bathrooms. During the entire week noisy teenagers passed within inches, but she never betrayed herself and the two eggs she was incubating. It wasn't until the final day when Marvin, my Costa Rican colleague, spotted her and pointed it out to me. Such is the value of protective coloration and a behavioral adaptation to keep still in the presence of danger.

Manakins are celebrities among tropical American birds. The brightly-colored males take time off from picking berries for food to gather in leks, communal display grounds, to impress the females with their frenetic dance steps. (Perhaps not unlike males of another species.) They dart between saplings and dance floor in an attempt to woo the females. In the process they snap their wings, producing a sound like that of a breaking twig. Often I tried to find out what was producing that sound, but the constant movements and broad leaves kept it a secret until Eylen filled me in.

Another notable sighting was that of the rare Agami Heron (Agami agami). A lagoon near the South Station is one of the few known breeding sites for this uncommon bird. The lagoon was the destination of a nature walk we made during a visit to larger of the two Pacuare biology stations. We saw about 10-14 birds perched in trees along the water's edge, while others flew out or gliding in to roost. Unfortunately, the telephoto lens on my camera doesn't have the power to reach them, so I include a photo by Ricard Garrigues that I found on the web.