It was early realized that most of the diversity of life residing in the rainforest is found, not at the convenience of ground level, but frustratingly high in the canopies of the trees. And it is not just birds and arboreal mammals like monkeys and sloths that dwell in the canopy. Thousands of species of insects, frogs, snakes, lizards, as well as epiphytic orchids, bromeliads, mosses, and ferns, live up where it is difficult for us humans to venture. Going to the rainforest and observing only those plants and animals visible from the forest floor would be analogous to visiting New York and seeing only the part of the city visible from the windows of a subway train!
To overcome this limitation, ACEER constructed a catwalk 75-115 ft above the forest floor in the midst of the rainforest canopy. This is the only structure of its kind anywhere in the Western Hemisphere. This world-famous Canopy Walkway zig-zags among wooden platforms attached like treehouses to 11 different trees, covering a total distance of over a quarter-mile. Some of the spans are more than 150 ft in length. The whole thing is reminiscent of the Swiss Family Robinson's treehouse, only on a much grander scale.
The backbone of the walkway is a series of paired steel cables strung between trees. Suspended between the cables, forming a deep trough, is stout cargo netting. Aluminum ladders are laid in the bottom of this trough and covered by long 1 × 12" wood planks. From the arrangement of bracing, struts, guy wires, and so forth, it appears that the walkway was very carefully engineered. It certainly was relatively stable, with minimal sway.
Nonetheless, I found the whole thing a bit unnerving. Not so much at first, when I was totally enthralled by its novelty, but later, when I was about halfway through and had had a chance to think about just where I was. I wasn't worried about falling off; the netting was so high, I don't think you could get out of it if you tried. No, I was more concerned with structural failure. After all, we were in the rainforest. Things like wood and rope rot quickly in the rainforest, and termites are very common there. Furthermore, trees and branches are always falling in the rainforest. I wasn't so much worried about the trees supporting platforms falling, as I was that a branch from an adjacent tree would crash down upon the walkway. I knew that the rules forbade more than three persons on a span or four on a platform at one time, ostensibly to minimize stress loads. But as I thought about it, it occurred to me that this was also a smart way to minimize casualties in the event of disaster.
Apprehensive as I was, it did not interfere one bit with my enjoyment of the walkway. It was absolutely incredible to be up so high in a tree! I'd never done much tree-climbing as a child, but even if I had, it never could have compared with this! I was especially fascinated by all the epiphytic plants, e.g., tank-bromeliads like Aechmea and Neoregelia, some of which were in gorgeous bloom. High-climbing lianas like the elephant-eared Philodendron were also readily observed. Birds of all sorts were observed, and on a couple of the trees, we saw small lizards who lived in the hollow limbs out basking. Not only that, but the air was much more pleasant in the canopy, less humid, with occasional breezes. I spent nearly two hours covering the quarter-mile length of the walkway and loved every minute of it.
We returned for lunch (chicken and noodles) at noon. At 2 PM, Hardy, Jim, and I took some of the students out to review plant families and their characteristics. We saw Piperaceae (Peperomia, Piper, and Pothomorphe), Gesneriaceae, Apocynaceae, Lecythidaceae, Passifloraceae, Acanthaceae, Strelitziaceae (Heliconia), and many others, some of which I wasn't too good at recognizing right off. Thank goodness for Jim, who had taught taxonomy much more recently than me. It rained just briefly; sweat-soaked as we were, we hardly noticed. I seemed better able to cope with tropical conditions today, though some of the students who had been quite gung-ho the day before were now starting to flag.
We returned by 4:30 PM and spent some time trying to identify specimens as a group, using Woody Plants of Northwest South America by Alwyn H. Gentry (Conservation International, Washington, 1993). It was a rough go, particularly with nothing but hand lenses for magnification and nothing but oil lamps for illumination. Dinner was at 7:30 PM and featured a slightly different version of chicken and noodles. Again, I eschewed Larry's night hike, spending the evening hours cooling off in a hammock. This was our last night at ACEER.
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