IF YOU GO

* Eco-Tours: Apartado 465, Panama 9A, Panama.

The Barro Colorado tour costs $75, including transportation and lunch. A "significant portion" of the fee is donated to the Smithsonian Tropical Research Institute for upkeep of the trails and facilities. Other Eco-Tours trips: * Soberania National Park: visit Pipeline Road, a section of rain forest where bird-watchers go each year just after Christmas for an annual competition. Cost: $45 per day, including transport and lunch. * Overnight trip to Nusagandi Park, operated by the Cuna Indians. Cost: $149 including meals and transportation. * Eco-Tours also organizes longer trips for groups from abroad, including a 14-day trans-Darien tour and a package trip to a rustic island lodge, also run by Cuna Indians.