WE'VE dodged the sinuous webs of spiders that lasso their prey. The barbs of the Black Spine Palm were easily avoided. As directed, we did not touch the brilliant but poisonous frog. We went our way, and the snorting feral pig went his (although we did catch a whiff of his foul "musk," as our guide Richard Cahill euphemistically calls it).
But the genial bond between tourist and tropical-rain-forest guide takes a precarious turn when, moments after spotting a large flock of vultures circling overhead, our trusted helmsman mutters: "Now where did that trail go?"
A long 15 seconds later, Mr. Cahill cheerfully announces, "Ah. Here it is!"
Welcome to Eco-Tours de Panama, S.A. This two-year-old tour company has the only concession to show visitors one of Panama's great oddities: a rain forest smack in the middle of the Panama Canal, a waterway transited by some 12,000 cargo ships annually.
But this is far more than a median-strip slice of trees on a maritime highway. Known the world over by tropical researchers, Barro Colorado Island and five peninsulas constitute the oldest tropical rain forest reserve in the Western Hemisphere. In building the Panama Canal (completed in 1914), the engineers created Gatun Lake, one of world's largest man-made bodies of water. The 3,800-acre island in the middle of Gatun Lake and the nearby protected peninsulas are a cornucopia of botanical and biological life. Residing here are more than 365 species of birds, 1,369 plant species (and counting), 300 species of butterflies, 200 kinds of ants, 90 species of mammals, and 50 species of reptiles and amphibians.
Scientists have been studying the island life since 1923, and the Smithsonian Institute has operated research stations here since 1946. The area is off-limits to the public. But Eco-Tours has been given permission to run a boat tour into a cove at Barro Colorado and a walking tour on one of the peninsulas.
"The rain forests are an integral part of the canal ecosystem. They help maintain the water table and prevent the canal from silting in from erosion," explains Heran Arauz Torres, Eco-Tours operations manager, as our johnboat skims across Gatun Lake.
The lake is home to crocodiles, caimans, peacock bass, tarpon, dolphins, and manatees. Picked up from the hotel at 6 a.m., we don't spot any of the aquatic life. But by 7:30, we're in sight of Wheeler Cove. A pair of Red Lord Amazon parrots scoot overhead.
"Early morning or just after a rain is the best time to visit what we call 'the most accessible rain forest in the world,' " says Cahill, an American born and raised in Panama.
Arauz shuts off the throaty 55-horsepower Evinrude. The launch, equipped with binoculars, bird books, and souvenir Eco-Tours caps, eases into the cove under power of a softly humming electric motor.
Arauz calls out the names of the birds singing: toucan, Amazon kingfisher, a red-breasted trogan. We scan the trees with binoculars as he attempts to point them out. We glide closer. Listening intently.
"That's the black-faced anthrush. It's very elusive," says Aruaz, as he tries to draw the bird out of the woods by imitating its short-long whistle.
The son of Panama's most famous anthropologist, Reina Arauz de Torres, Arauz grew up tramping through the jungle. His parents were featured in a 1961 National Geographic article as the first to drive through the Darien, a stretch of tropical forest in southern Panama once thought impassable.
As an adult, Arauz pursued a career as a diplomat, spending time in Washington as a representative to the Organization of American States. But after six years on the black-tie circuit, the call of the wild drew him back. "I heard this company was forming and I left," he says.
Moving to another inlet, we're treated to the sight of a dazzling blue Morfu butterfly. Howler monkeys are spotted in the treetops. A Balsalisas lizard scampers along a log.
Apart from Arauz's incessant anthrush whistle, the early-morning visit to Barro Colorado has a calming, tranquil quality. But as the sun and heat rises, the fauna become harder to spot.
Arauz coaxes the gasoline engine back to life and we head for an old research station on a peninsula. A wild pig named Fefa, who was befriended by the scientists, greets us like an abandoned puppy.
Fefa? "Someone called her 'Fea,' which means 'ugly' in Spanish," explains Cahill. "They decided that was too unkind. So 'Fea' became 'Fefa.' "
The highlights of an 90-minute loop through the sweltering rain forest include close encounters with white-faced monkeys and a family of Gato Negros (commonly known as High Woods Dog in English) which wandered within a few feet before discovering us and scampering off.
Eco-Tours offers a unique adventure, if a bit rough around the edges. Our two guides, while fairly knowledgeable, were stumped a few times by questions about flora and fauna. The ice-water and submarine sandwiches were welcome (though soggy). But defending the meal from the flea-infested Fefa was not the most relaxing way to end the expedition.
Cahill notes that although eco-tourism is a major revenue generator in neighboring Costa Rica, it's a new development here.
In February, Eco-Tours graduated its first class of nearly two dozen guides from a one-year-long training course which draws on the expertise of local experts, including Smithsonian researchers.