West of the Fields

A tropical ecologist reporting from the field. Musings on life and art, botfly extractions, tropical plant identification, beer, parrots, machetes. Etc.

Monday, August 21, 2006

Bala #4

La Selva has more than 450 ant species, but there’s one that garners more than its fair share of press: Paraponera clavata, the giant tropical ant, variously called bala, bullet ant, or veinticuatros. The latter because, legend has it, the sting puts you out of commission for 24 hours. Unlike most ants of the temperate zone, the bala has an honest-to-goodness sting. It clamps on with its jaws first, curls up to bring the business end around, and pumps venom into you. It’s not quite 24 hours of debilitation, and I highly doubt it’s as bad as getting shot, but it’s not something I’d recommend.

Bala #4 got me at the base of my right little finger, about 9:30 this morning as Marisol and I hacked through lianas and tossed the stems out of the plot. It wasn’t the lianas that took revenge, after all: it was the animal that, more than any other, uses them as thoroughfares.

A bala sting starts out as intense, shooting pain at a level comparable to about fourteen yellow jacket stings. You start sweating heavily around the site, great big weird drops of sweat like sap oozing out of a cut stem. Gradually the affected area goes numb and twitchy—the venom has neurotoxins among its many nefarious constituents—alternating with more pain. Repeat for 4-5 hours. Then, if you’re like me, you get a big bruise that itches for the next five days or so. So much to look forward to.

Yes, they are damn big ants.
(c) 2006 S.G. Letcher

Sunday, August 20, 2006

Las matas me matan

For anyone who might be interested in visiting La Selva Biological Station, here is a truism to bear in mind: paths with “sendero” in their names are much, much nicer than ones with “lindero.” The linderos are the old borders of the station property, established before the acquisition of various annexes, and as such they cut boldly through the forest in straight lines with no regard for hydrology and topology. Principal among them is the LOC, the Lindero Occidental (“western border”), which now more or less bisects La Selva. It’s among the hilliest and muddiest of La Selva’s trails, which is really saying something. And at the moment I’m establishing two plots which are accessible only by this trail. Why? you might ask. Indeed, I was asking myself the same thing all week. The technical answer has to do with the availability of c. 25 year old secondary forest and nearby, comparable old growth. If I hadn’t been the one to plan the plot locations, though, I probably would be convinced that it’s part of a conspiracy to ruin what’s left of my knee cartilage.

To be fair, the LOC runs through some beautiful country: streams overhung with palms and tree ferns and heavy vines; sharp ridges where you can glimpse monkey troops in the treetops almost beside you. In the old-growth forest, there are trees so large that their flanged buttress roots are easily twice my height. Besides the monkeys, I’ve seen countless birds, a turtle, a hognose viper, and a land crab that looked big enough to make a decent meal. But at the end of the day, I come back aching and weary, covered in mud, and usually soaking wet. The rainy season is upon us.

The plots are for a liana removal experiment. If I want to understand exactly how lianas are affecting the other plants in the forest, it’s not enough to just observe them. I’m planning to remove the lianas from half of each plot, and measure the growth and establishment of other woody plants with and without lianas. Good science, and an excuse to hone my machete skills. So far, I’ve just set out the plots (300+ PVC tubes and untold meters of string arrayed strategically in the forest) and marked seedlings in one of them. No lianas have been cut yet. The thing is, I think the vines have got wind of the fact that I’m planning to get rid of them. I swear, I’ve had more run-ins with unfriendly vines in these plots than anywhere else in the forest. On Friday, I gave Marisol the afternoon off for the Mothers’ Day celebration—a big deal in Costa Rica—so I was working by myself. I ran out of PVC tubing and headed back to the end of the plot where I’d stashed the rest of it. Halfway there, an errant vine snagged my heel and sent me sprawling a full ten meters downhill, where I hit a tree and tumbled a few more meters. It probably would have been hilarious, if there’d been anyone to see it. Fortunately I was unhurt, aside from the spines still embedded in my left hand from the spiny palm I tried to grab on the way past.

When I got back from the field Friday afternoon, later and more bedraggled than usual, Franklin came out of his office (which has a good view of the boot-wash station) to ask what had happened.

“Las matas me matan,” I told him. The plants are killing me.

“Si. Parece que le tiraron al suelo y le pegaron.” Yeah, it looks like they threw you in the dirt and beat you.

I had to laugh. It was pretty damn close to the truth.

Wednesday, August 09, 2006

After-hours at the serpentarium

Here is my latest advice for Keeping Life Interesting: hang out with herpetologists. If nothing else, they’ll give you the kind of vicarious thrills that botany, sadly, rather seldom provides. This week, for instance, I saw Franklin get bitten by a two-meter anaconda (don’t worry, he’s fine).

Those of you with a background in biogeography may be scratching your heads. Yes, anacondas are native to South America. (And yes, like Ben Affleck, they did co-star with J Lo in a horrendous movie or two. That is irrelevant.) Well, the only anaconda I’ve seen in Costa Rica—the only anaconda I’ve seen anywhere, actually—lives in a room-sized cage at the back of the Serpentario in La Virgen de Sarapiquí.

Late Sunday afternoon, Franklin invited a few researchers to come and see his charges at the serpentarium, where he works as a consultant a few days a month. It was the tail end of a rainy weekend; I was up for anything.

We wandered through the maze-like aisles of bored and imperious pit vipers, nervous little vine snakes, and great looping coils of boas, all behind glass in box-like cages. I have no great love for slithering things, but I must admit they can be gorgeous. My favorites are the eyelash vipers, petite and deadly snakes that often coil up on heliconia bracts and ambush hummingbirds. They get their name from the row of elongated scales above their eyes, which really do bear an uncanny resemblance to false eyelashes. The vipers come in many colors: mottled brown, licheny green, and a bright golden morph, called oropel, that’s only found in Costa Rica. (The first time I saw one in the field, I thought, that’s weird; who left a coil of yellow lobster warp in the jungle? That’s what you get for growing up in Maine, I guess.)

The main attractions at the serpentarium are kept in the back, in cages just slightly larger than a typical college dorm room. At one end, there were two gigantic Burmese pythons, asleep in coils the size and shape of beanbag chairs. The cage in the middle held a snake with an even closer resemblance to furniture, or at least with a closer resemblance to furniture than to anything herpetological. It was an albino Burmese python, mottled white and yellow, and grotesquely obese: about three meters long and nearly as thick as my waist. The head, bigger than my outstretched hand, seemed a comical afterthought.

“Mire, está despierta,” Franklin said. She’s awake. “Ella es amable; podemos tomar fotos.” She’s friendly; we can take pictures.

He stepped up and unlocked the cage. It was never my intention to make friends with an 80-kilogram python, but to my surprise, as she nuzzled up against me and blinked her red eyes, I found myself thinking she was kind of sweet. (Johel hasn’t downloaded the photos yet. Stay posted.)

In the cage next door was a different sort of beast. A streamlined bolt of sinuous muscle, dark gray-green, lurked beneath the water of its pool with only its nostrils showing. Its little eyes, set far forward on the muzzle, regarded us with reptilian loathing and composure.

“Ella es un poco más mordedora,” Franklin said conversationally. “Mejor que no entren.” She’s a biter; better not come in.

He unlocked the door and took one step toward the pool. The snake lurched up out of the water with astonishing speed, lunging forward at least a meter and a half to sink a tooth into Franklin’s leg just below the knee. Then she sank beneath the water again.

The other researchers and I stared at each other, open-mouthed: did that really just happen? Franklin let himself out of the cage, calmly, and went to ask the director of the serpentarium for some alcohol to clean out the wound.

“It was just a warning bite,” he explained to us when he returned. “When they really want to bite something, they hang on with all their teeth and gnaw.” He told a few stories about anaconda-hunting in the Amazon for a serpentarium where he used to work, walking around barefoot in a swamp until you felt the snake slither past underwater, then grabbing it and hoping you were close enough to the head to keep it from biting you.

“Este es mi mundo,” he said. This is my world. Fascinating as it is, I have to say I’m glad it’s not mine.