One of the least known areas of the planet lies 10 to 60 metres above our heads in tropical countries: the tree tops of the rain forest. The tropical forest canopy is home to some 40 per cent of all species found on our planet, and perhaps 75 per cent of these millions of species are still unknown to science.
The vehicle that boldly goes where few people have gone before in the world’s main treasure house of biodiversity is a modified ski-lift Rolex Laureate Donald Perry calls the Rain Forest Aerial Tram. Built in Costa Rica where Perry has carried out most of his biological research, the tram is a noiseless system of cable cars travelling slowly through the tree canopy.
Opening a New World
For anyone who imagines Central America’s tropical rain forest as dimly lit and surprisingly empty of animals — more like a cathedral than a zoo — travelling the canopy on the unique tram offers glimpses of a completely different world. All but the smallest of rain forest trees put forth their leaves, flowers and fruit in the well lit canopy. Many plants, such as orchids, bromeliads, cacti, lichens, mosses and ferns, flourish in the canopy as completely different species from those below. Butterflies, moths, birds, bats and bees are found here in abundance, many of them never seen in the ”understory”. Snakes, giant ants and tree frogs — some of Costa Rica’s specialties — are all visible from above, instead of being obscured by undergrowth. The canopy has lizards and earthworms that never touch the ground. Central and South American mammals are almost completely nocturnal, so the Rain Forest Aerial Tram also offers a rare chance to study spotted cats, deer, pigs, racoons, rodents and possums. The rain forest canopy, Perry points out, contains "the most complex communities of life on earth".
An Unwelcoming Habitat
Perry won a 1984 Rolex Award for Enterprise and developed the Aerial Tram as a result of his efforts to overcome the problems of biological research into the tropical forest canopy. The canopy world flourishes at the equivalent of the “15th floor” of the rain forest, 50 metres up. It is difficult to study from ground level because of the dense vegetation that obscures the world above. Three-quarters of rain forest trees have limbs that are too weak to climb. Many rise 25 metres without branching. Snakes, scorpions, numerous ants and troublesome insects are a further deterrent.
Tree-top observation platforms make canopy research "a frustrating exercise", says Perry, "because an altogether different set of species, for example, might inhabit an adjacent tree which is in view but beyond the reach of a platform-bound observer." At first he used a crossbow, mountain-climbing rope and clamps to gain some flexibility. But this required sturdy branches for suspending the rope.
A Web for Humans
Then in 1978, studying the role of herbivorous bats in dispersing seeds of the monkey-pot tree in Costa Rica, Perry hit on the solution: a special web of ropes and cables that permitted unrestricted movement across a canopy. With John Williams, an engineer friend from California, Perry developed a system for a platform, 400 metres of rope web, pulleys and descent ropes, with which he could move from ground level to above the tree top and anywhere inside the canopy world. "The combination of the web and the descent ropes gave unrestricted movement through a volume of forest an acre in area and 30 metres in depth, opening great biological wealth to observation," Perry recalls.
Despite Perry’s ingenuity, the harness and pulley system still required scientists to be extremely athletic, and most found it too dangerous. With Williams he designed the Automated Web for Canopy Exploration (AWCE), using a stainless steel cable, a rigid chair and wireless controls. This took much of the fear out of canopy research and enabled two researchers at a time to manoeuvre up to the canopy at 30 centimetres a second. The AWCE design won him a Rolex Award, and Popular Science said it "promises to open the jungle to research the same way scuba gear opened the oceans".
"The Award was a turning point in my life," says Perry. "It brought opportunities and vistas that I would never have imagined." A fellow biologist from the United States, Amos Bien, offered a site for AWCE at Rara Avis, an eco-tourism resort run by his non-profit foundation in the Costa Rican mountains.
Revisions and Research
Nevertheless, Perry spent three fruitless years trying to raise funds from non-profit and scientific organizations to develop the project as originally envisaged. "I eventually decided to build a less expensive system, and the project was completed in December 1987." Almost immediately it became the cover story in the New York Times Sunday Magazine. But it still took until June 1992 before he could open an associated research station to house a driver and scientists.
But the publicity Perry reaped from his Rolex Award aroused intense interest well outside the scientific community. "More and more travellers, especially scientists, doctors and professionals of all kinds, wanted to see my work," Perry reports. "Everyone wanted to ride on AWCE."
This led to the development of the Aerial Tram. "AWCE was supposed to be a research vehicle and it was built for only two people. It was obvious that something different was needed to serve the tens of thousands of people who wished to see the canopy," notes Perry. "So in 1991 I established Dosel S.A., a corporation devoted to educating tourists and students about the mysteries and values of canopy communities. So far I have raised several million dollars from investors committed to protecting nature."
The canopy tram operates on the edge of Braulio Carrillo National Park, 50 minutes by bus from Costa Rica’s capital, San José. Dosel (Spanish for canopy) and other investors bought 450 hectares of almost untouched rain forest containing six distinct ecosystems. The site is one of the best examples of canopy environments on earth, unmatched by other locations in Africa, Asia or Australia, Perry says. Sixteen gondolas carry up to 100 tourists on a two-hour trip through the canopy. To deepen the visitors’ understanding of rain forest ecology, guides also take them on a tour through the jungle at ground level.
Tourism Carefully Controlled
Perry is determined to ensure the project remains environmentally sound. "Uncontrolled nature tourism can best be called eco-destruction," he declares. "Often the influx of too many visitors has caused wildlife to retreat to more remote areas. Tour guides invade the forest to search out subjects for tourists with their cameras at the ready, and reduce the areas where wildlife finds refuge. The stress inflicted on plants and animals in these areas is apparent."
He also wants to ensure that local people benefit, and not just financially: "All over the world, tourist businesses are designed to take wealthy foreigners into nature to fish, white-water raft, or bird watch. These expeditions are too expensive for the majority of local people. So the people who desperately need to be educated about the value of nature are the ones excluded from learning. This is a kind of vacationer’s imperialism. Locals learn to view nature as the wealthy man’s playground. When they can’t afford to belong to the exclusive club, onlookers harbour an attitude that breeds contempt for nature."
Perry plans to use the spare capacity on the tram to offer free trips to Costa Rican students, 800 of whom have already been taken into the treetops, and to provide ticket discounts for Costa Rican citizens. Night rides on the tram are few and mainly restricted to scientists.
Perry also redesigned the ski-lifts to make them less intrusive on the environment. The towers were changed from conventional "T"; shape to an "F".
"Incoming cars ride over outgoing cars, allowing a much narrower passageway — about three metres — through the forest," Perry explains. "The seats are two across, in three rows, which puts everyone next to the forest. This is the first ski-lift design that respects the forest."
"The Rain Forest Aerial Tram is a direct result of the Rolex Award," Perry stresses. "The Award brought a tremendous amount of international exposure that was critical in elevating the world’s awareness of the need to preserve this complex habitat. This has also led to a much greater number of scientists studying the canopy. It is a glorious success.”
Published in 1996