Tobago's humming reserve.

• Position: Americas iojo!

TROPICAL, TOBAGO, anchored off the Venezuelan coast in the lower Caribbean, has made a name for itself as a popular destination for snorkelers and scuba divers, lured by the promise of swimming pool-clear waters and thriving populations of neon-colored fish, manta rays, and leatherback, green, and loggerhead turtles. But many of these vacationers might be surprised at learning to what extent the beauty and vitality of Tobago's coastline are the result of a farsighted environmental decision made more than two centuries ago.

Back in the mid-1700s, when Tobago was a British Crown Colony, legislators waged a decade-long battle to create a fourteen-thousand-acre preserve along the Main Ridge, a ruggedly mountainous spine that reaches heights of nearly nineteen-hundred feet and extends across the eastern two-thirds of this twenty-six-mile-long landfall. Despite heavy opposition, they won their fight to establish the highland watershed and now, nearly 250 years later, the Main Ridge Forest Reserve is still fulfilling its original mission of supplying high quality, fresh water to Tobago's current population of fifty-five thousand. But as the island's economic base shifts towards tourism, the reserve is proving an even larger environmental asset by protecting island beaches and offshore reefs from the destructive effects of soil erosion.

Promoted today as the Western Hemisphere's oldest protected forest reserve and a bird watchers' paradise, Main Ridge has become a stellar tourist attraction in its own right. Under the enveloping forest canopy, temperatures regularly hover in the seventies and frequent rains nourish an exuberant array of exotic plant life. Moss-covered palm, wild cacao, cypress, parrot apple, wild manjack, and cicropia are festooned in tangles of liana vines gum philodendron or crowned with orchids, bromeliads, and other epiphytes. More than 110 varieties of fern are on feathery display and graceful stands of bamboo, introduced from China in an earlier age, help stabilize the soggy mountain terrain. Wild hogs, crabs, frogs, nonpoisonous snakes, lizards, and countless colonies of labor-loving insects make their home in this dark, moist environment, but it's the reserve's plumed residents that have brought it lasting renown as one of the world's top birding destinations.

Among the favorite...