Articles > The Little Things That Change the World

“Nice millipede,” Dr Olson cooed as the creature began to measure itself out across his palm. “Look at all those legs. It’s a classic creepy-crawler!” To the uninformed eye this had looked like the perfect camping spot. We were in the far north-eastern corner of Costa Rica in a beautiful forest glade, sheltered by an ancient fig tree whose branches were so heavy that it had lowered vertical pillars to support their weight. It had seemed like a return to the benevolent arms of Mother Nature until our host began to agitate the tree’s nocturnal inhabitants with a probing flashlight.

There were millipedes, too numerous to count, and swarms of giant cockroaches, four-inches long, that seemed to triple in size when they flew. There were scorpions that were capable apparently of a painful sting that has the side-effect of anaesthetising your tongue and lightning-quick whip-scorpions that were cunningly devoid of the tail that should have served as a warning to us to keep our distance. From out of the darkness Dr Olson’s Bostonian accent could be heard proclaiming these “really neat…and they’re just soooo fast that I’ve yet to meet a scientist who’s successfully gotten bit by one.”

There were also clouds of swarming bees (mercifully sting-less) that construct a single pipe for defence against the marauding army ants that frequently sweep across the campsite devouring everything in their path. Occasional swarms of Africanised bees (known inaccurately – “at least in most cases,” according to Dr Olson - as ‘killer bees’) also buzz menacingly through the canopy where Charlie, the leader of the resident howler-monkey troop, would blast out his blood-curdling wake-up call for us at 4am.

The good doctor was clearly delighted with the riches of this diabolical menagerie, but then he is a man who has made a career out of a driving fascination for what he called ‘the little things that change the world.’ Even with this grotesque fig tree looming over our tent his enthusiasm was infectious.

After a month in Costa Rica, photographer Paul Bailey and myself had come to Santa Rosa National Park already convinced of the harmony that reigns in the forests of this most beautiful of countries. The jungles that we had so far visited here were benign places, considerate enough to confine their rainfall to the early-evening hours when we would anyway have been sipping Cuba Libres on the hotel balcony, or digesting rice-and-beans in a jungle-lodge hammock. They were paradisiacal, if sweaty, Gardens of Eden where cuddly anteaters bumbled towards you along the trail and where the only threat might be a mango thrown by an insecure howler monkey.

Then Dr Olson set to work filling us in on what is really going on among the tinier denizens of this hive of murder, torture and rape. “For most mini-herbivores life is truly brutish and short,” he told us. We learned about ‘tracker wasps’ that hunt down a particularly cute looking caterpillar only to impregnate its saliva-glands with their hellish offspring – with horrific accuracy they target the only part that has no immunity.

Olson’s assistant Dale Morris showed me a praying mantis that was nibbling a butterfly to death, and explained how the female can successfully find a nesting site and lay eggs even after her head has been bitten off, presumably in self-defence, by her amorous mate. I was introduced to a goofy-looking frog that hops obligingly onto your shoulder in the hope that you will blind yourself with its toxic excretions. It was enough to give us The Fear but then it did not take us long to realise that Santa Rosa NP is not geared to dealing with entomological virgins of our ilk.

The park was established in 1971 at the site of the national monument, the hacienda where a hastily recruited militia repelled an invasion led by the North American filibuster William Walker in 1856. (Costa Rica has no military and the reputation for peace that is the envy of Latin America seems to have left it at a slight disadvantage when it comes to battles of national importance). Although school-groups make an occasional pilgrimage to the old hacienda (and the hideous concrete neo-Soviet-block lookout-point on the hill above it) and a steady convoy of surfers endure the dirt-track that leads to the surfing-Mecca of Witches Rock, the park administration does not go out of its way to court tourists.

American ecologist Dr Daniel H. Janzen first recognised the importance of Santa Rosa’s forests and, enlisting the help of the local farming community, he has worked tirelessly to build one of the largest national parks and most important forestry research centres in Costa Rica. Today only 2% remains of the dry tropical forest that once covered Central America’s Pacific seaboard, and Santa Rosa (at almost 40,000 hectares) represents the largest single tract. The global importance of Costa Rica’s forests has recently been reinforced at a world summit where the country’s president raised the delightfully logical (if improbable) idea of establishing an oxygen tax, payable by the nations that use the most oxygen to the countries that produce it.

At any one time there are over a dozen scientists, students and volunteers in residence at Santa Rosa, studying everything from jaguar territorial requirements to parasitic infestations in the guts of assassin bugs. Dr Eric Olson’s team is principally studying the way in which caterpillars in this area predict the change of seasons to such an extent that they invariably arrive on the scene even before the trees have begun to push out their new shoots.

The seasonal feeding-frenzy is so intense that a steady drizzle known as ‘frass rain’ sprinkles down from the canopy as the caterpillars literally inflate themselves with vegetable matter. The best way to quantify the numbers of little grazers in the canopy is to harvest this frass and Dr Olson is supported in this task by volunteers from Earthwatch Institute who invariably have stories to tell about loved ones who are struggling to accept the fact that ‘Mom has flown off to a remote part of Central America to spend a fortnight collecting caterpillar poop.’

Apart from ‘frassing’ and the collection and breeding of the butterflies, the enquiring mind of Dr Olson is also constantly coming up with separate spin-off studies that have students searching the rainforest for undocumented species of jumping spiders, parasitic wasps and whatever falls in their way as they, quite literally, beat the bushes in search of sundry ‘creepy-crawlers.’ Among other discoveries is a unique spider that differs from all others in that it is not technically a hunter but makes a living by ‘mugging’ ants: “It could be properly termed ‘an obligate parasite of a mutualistic symbiosis,’” Dr Olson grins, “…you want I should spell that?

“Humble bugs are the major converters of plant matter into animal matter in the tropical forest canopy,” he points out with an obvious feeling of awe that five years in the forest have not managed to diminish. Watch one of Olson’s zebra swallowtail caterpillars feeding – and try as you might you just can’t do anything to stop them feeding – and it becomes easier to believe that these miniature herbivores are capable of eating more vegetation across a given area than the legendary (and infinitely more intensely studied) herds of the Serengeti. And the parallel doesn’t end there; research has already established that what were once labelled as ‘pests’ are actually vital to the well-being of this habitat and that they require large areas for migration. Latin American parks need to be interlinked in much the same way that Africa’s trans-frontier parks have been adapted to keep migration routes open.

The various teams of scientists and volunteers at Santa Rosa are devoted to the survival of this most endangered of habitats but the sum of all knowledge that is turned out of the research centre influences the way in which other reserves, not only in Costa Rica but also across the world, are managed. After five years the Earthwatch project has broadened to the stage where Dr Olson admits that, unlike his voracious subjects, he occasionally begins to wonder if he might have bitten off more than he can chew: “My goal is now nothing less than to take the pulse of an entire ecosystem!” he smiles.

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