Stories from the Field: Climate Change and Caterpillars in Costa Rica
Ecologist Dr. Lee Dyer of Tulane University, principal investigator of the Earthwatch Climate Change and Caterpillars expeditions in the U.S. and in Central and South America, has long been aware of the frantic pace of rainforest destruction. Dr. Dyer once said, “One of my greatest fears is that so many unique and interesting stories may go untold,” referring to the extraordinary lives of the insects he studies. In this excerpt from his field journal, however, Dr. Dyer describes coming to grips with other, more primal, fears.
La Selva, Costa Rica - It feels great to be in wet and wild Sarapiqui again. Today in the field I was thinking about how this rainforest doesn’t have the same feel as it did 10 years ago. Of course, the region has seen some of the same negative changes as the rest of the natural world in the 20th century, but I was focusing on my improved perspective on the forest. I am no longer afraid. Or, put more accurately, I now relish my fears.
My first visit to the tropics and to this rainforest came when I was starting graduate school in 1991, and I had never spent time in broadleaf forests. I was a desert rat and mountain lover, and all I knew about rainforests is that we were losing hectares every hour. I felt the same awe that Wallace and Darwin wrote about, but I must admit that I was filled with phobias about tropical forests. I experienced everything from mild fears of hot, humid weather and bot flies, to more intense fears of malaria and snakebites. I even feared falling in love with a forest that could soon be destroyed. I felt incredibly claustrophobic here at first-all that green pressing in from every direction, something always crawling up my leg or sliding down my forehead, and the persistent, inescapable smell of mold.
I’m still emotionally partial to tops of mountains and the dry open desert with their agoraphobia-inducing vistas, but I’ve grown to love all jungle phobias (including the beetle ironically named Agra phobia). I like the staggering biological diversity behind these fears, and the fact that I know a little more about these plants and animals that are crammed together, pressing in on me. A decade ago, I thought the forest was beautiful, but it also presented itself as an impenetrable wall of green that was hard to fathom. I was troubled by the daunting task of designing a research program in such a complex system. It was my ignorance that presented the problem, and a decade of living with these creatures, looking beyond my fears, and closely examining interactions between selected species has eroded away some of that ignorance.
Now some of the same critters I once feared have stories and names that put them in an appropriate ecological, historical, and personal perspective. Like the ctenid spider (Cupiennius coccineus) crawling up my leg. I gently flick it off and watch it scurry over to the cover of a small chaperno tree (Lonchocarpus oliganthis). A huge ctenid actually bit me once and delivered a fair amount of toxin, but I survived. It bit me in the middle of the night on an uncomfortable spot, so I immediately flung it away without catching its Latin binomial. The next afternoon I had mild hallucinations and passed out for a couple of hours. I awoke to the sound of a tinamou whistling its eerie notes in the distance. A couple of smilisca frogs were bleating their whereabouts, and as I listened it occurred to me that along with the beauties of this forest, I really like the toxins, dangers, discomforts, and complexities, just like I love the thrill of climbing the soft, crumbly sandstone of a desert tower.
None of the spiders here pose a serious threat to humans, as it turns out, but they can be fierce predators and important regulators of other animals. One of the most fascinating things I saw during my first visit to the rainforest was a wolf spider catching and eating a frog. That is probably why I spend so much time thinking about who eats whom in this forest. These spiders eat lots of caterpillars and in turn, are eaten by tinamous and even by some of the same kinds of parasitoids that eat the caterpillars I study. I’ve learned that pressures from those who might eat you are much stronger here in the tropics than they are in more temperate habitats.
As I was turning leaves today, looking for morpho and arctiid caterpillars, I was reminded of all the forests I have ever visited. I thought of our collective ignorance of the ecosystems that humans are a part of and how my initial fears were driven by an ignorance that no amount of books, lectures, and carefully planned experiments could remove. I realized that, both as a scientist and as a naturalist, learning basic natural history in the forest is a hands-on, at times gut-wrenching process. The more I personally experience this forest, the more I love its terrifying complexity and understand how it might be managed-and saved.
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