Herpetology 101

Franklin is working as my assistant right now, studying plants, but he’s really a herpetologist by trade. On days when we finish our fieldwork early, we walk back slowly from the plots and explore the forest, trading the knowledge from our respective specialties. My frog-catching abilities, which have lain dormant since I was about 12, are suddenly useful once again. Last week I caught a little Bufo hematiticus, a toad that lives in the leaf litter and blends so well with the grays and browns that I never would have spotted it if it hadn’t moved. Franklin showed me how to tell males from females: the males have an extra stub coming off their thumbs, a spur they use in combat and for amplexus (clinging onto the female during mating). Also, if you grasp a male toad behind the ribs, it will usually give some kind of signal—chirping or vibrating its throat—to keep other male toads from trying to mate with it. Or in Franklin’s words, “es para decir al otro, ‘suave, suave, mae, no soy playo’” (it’s to tell the other guy, ‘hey, easy, buddy; I don’t swing that way.’) Apparently this is a common problem in toads, except in the species where the males and females have evident exterior differences. Male toads in mating season will amplex with just about anything that moves. (If you’ve ever seen the movie Cane Toads—and everbody should see that movie— you know that sometimes they’ll even amplex with things that don’t move. Like beer bottles, for instance.)

I feel comfortable now catching frogs and lizards—at least the non-toxic frogs, and the little lizards that don’t bite very hard—but I let Franklin deal with the snakes. Snakes are his real joy, everything from tiny leaf litter snakes that fit in the palm of his hand to giant pit vipers.

Sometimes our encounters with herps are a little closer than we might prefer. Last week as we were surveying a plot about 3 km into the forest, Franklin had a close call. I was finishing up a sapling census while he went back to get our backpacks for lunch and water. I heard him heading off into the forest, and a few moments later I heard “hue puta!” (son of a bitch) and then “...que linda culebra” (what a gorgeous snake). Fearing the worst— because Franklin would call any snake beautiful, no matter what it did to him— I yelled up to him, “que pasó?” Nothing, fortunately. He’d slipped on the muddy hillside and landed with his hand about a meter away from a coiled-up terciopelo (fer-de-lance, Bothrops asper), the second-largest pit viper in this region and one with a reputation for ferocity. The reputation may be undeserved, though, because in this case the snake just uncoiled and took off. (Note that the snake in the photo is not a terciopelo. It's a Leptophis, most likely; non-venomous, at any rate. Anybody who did that with a venomous snake would be asking for a trip to the hospital!)

Later in the week I had a close call of my own. We were finishing up a seedling survey in one of our plots. I was about to reach for a tag, when an enormous serpent uncoiled from the forest floor barely a meter away. It was as thick as my upper arm, with the unmistakable wedge-shaped head and diamond markings of a terciopelo. After a heart-stopping instant when it came straight towards me, the snake turned downhill and vanished. Maybe I’ve been spending too much time with my dear herpetologist, but it really was a lovely snake. Its scales had an almost iridescent sheen, and it moved with such grace and precision. It was hard to believe that something so large and beautiful had made itself invisible just by holding still.

As we continued down the seedling plot, Franklin commented that it was the healthiest-looking terciopelo he’d seen in a long time: “ella era bien gordita” (she was nice and chubby). I asked how he knew it was a female from that brief glimpse, and he said that only the females get that big. And it was big—my seedling plots are two meters across, and the snake nearly stretched from one side to the other when it took off. I asked him to make a note on the data sheet so we’d remember to watch out for it when we came back to survey the saplings. The margins of my data sheets are usually full of little warnings like that: nido de avispas (wasp nest) en XB135, flacas (ants with a nasty sting, genus Odontomachus) en B150. I had to laugh when I came across Franklin’s note as I entered the data: X135: B. asper ♀ c180 cm. Muy buena condición.