Monteverde

Home of a Quaker community transplanted in the 1950s. Home of delicious cheese. And former home of the Golden Toad. Monteverde definitely rates as one of my favorite sites this semester: pleasantly cool mountain air and mossy cloud forests. Monteverde itself can be an ambiguous place since that name is pinned to the region around Santa Elena, the actual town of Monteverde, and the 3 or 4 private reserves along the mountain. The San Gerardo Station where we stayed for the week is inside of the Bosque Eterno de Los Ninos (Children's Eternal Forest) (which, by the way, has a neat story about its establishment). Although we had limited electricity and no internet, we did enjoy the luxuries of hammocks with gorgeous views of Volcano Arenal and empanadas and coffee every afternoon. They take tourists! So check it out if you don't mind hiking in and out an hour.

Mark Wainwright, a herpologist and incredibly talented naturalist, gave a series of lectures about amphibian taxonomy, frog calls, and the amphibian decline in the 1980s. Mark is one of the best teachers that I have ever seen. He's lectures were so engaging and dynamic, he handled all the questions beautiful, he clearly understood and passionately loved the material. So great!

We'll skip over the taxonomy; I'm not crazy about Latin names. Learning about frog calls gave me a new respect for acoustics. Some frog species will call in choruses, with each frog singing in turn according to a hierarchy. So none of the calls overlap! How do they do that? And the tone of the songs will change with temperature and their hearing also changes with temperatures. Females at 25 C, for example, will respond to recordings of male calls made at 25 C. How crazy is that! Female hearing changes with temperature to match the changes in the male frog calls. And, this is almost the best part, Mark spends a lot of his time as a naturalist searching for frogs and recording their calls. Because there are dozens upon dozens of species out there whose calls we don't know. Without that information, we cannot reliably census frog populations, study their mating behavior, or a million other basic things.

Now here is the short version of the Amphibian Decline: In 1986, a researcher counted 1500 Golden Toads on a ridgetop in Monteverde. This critter lives belowground and only emerges once a year to breed during the heaviest rains. After that researcher secured funding and returned the next year, there were only seven toad. Similar versions of this story played out all across North, Central, and South America, mostly in mountainous regions and mostly in species that lay their eggs in the water. Here are the simple explanations that do not quite seem to fit the entire story: increased ultraviolet exposure from the thinning ozone layer, pesticide residues, disease alone, climate change.

After 20 years of research, scientists think that the frogs died from a very aggressive aquatic fungus that infects their skin. Some scientists think that this fungus was introduced from Africa, so it is an invading exotic. Other scientists have found this fungus in ponds and rivers where they find plenty of healthy frogs. So they think that global warming compounded a particularly harsh El Nino year in 1986 and left the populations more vulnerable to a naturally occuring fungus. So no one really knows. We do know that some species disappeared and some populations were decimated. Now, we have also seen many populations gradually increasing. So there is an almost happy ending to the story.

More on Cabo Blanco and La Selva tomorrow!