The Itinerant Biologist And Other Stories: Field Research in a Field: Very Unfriendly Cows, Many Glass Frogs, and a Nice Dog

We recently completed a set of pastures sites attached to an idyllic set of casitas. Arriving on a Sunday, we found a large extended family or two relaxing-- kids in the river, senoritas to abuelitas in the shade of the porch. They were mildly interested in the gringas wanting to look for frogs on a sunny weekend, but not at all taken aback; this land had been used for other studies by scientists before us. After a very steep climb up the hill, we were greeted by fantastic views of just-as-steep neighboring hills to distant mountains half-obscured by clouds. The sun beat down as we headed off in search of our three land and three stream transect sites. Selecting the land sites is pretty easy; we pre-select some well-spaced tree or patch and a random angle to start from and go. We are usually more limited on stream availability; this site didn't have too many, so we spent a lot of time walking around the hills trying to find some streams of consistent size.

Our plans were severely complicated by a few groups of cattle that were, shall we say, not thrilled to see people creeping through their home. Our first interaction with the cattle involved an unyielding bull-- we skirted him and his herd and went on our way, hugging the fence. Later in our expedition, we descended into a valley bounded by a large river. Cattle faces poked over the ridge. The cows and calves jostled each other for a view, the bull guarding them started getting pissy and making some very deliberate eye contact and incremental movements towards us. Then, the herd started meandering in our direction, despite our hoots and hollers. I broke out my garbage bag, waved my stick, made threatening yells and "you're in trouble" sounds that would stop any horse in its tracks. But these cows, they did not care. They approached. The bull glared some more. He swung his head and stomped his hooves. After some hasty deliberations and calculated risk assessment (skirt around the herd to unknown pastures on the other side of the hill?), we retreated into the river and crept along its banks to a cow-free pasture. From then on, we didn't stray far from fences or thick vegetation in case of marauding cattle.

It was a fairly fruitless day; we had started transects later in the day than usual, didn't find much (as expected in day surveys of pasture), and didn't get all of our transects set up due to cow interference. We returned in midafternoon the next day to finish our day transects before dusk and night surveys. We were immediately befriended by two pups, one of whom latched onto us and kept us company the whole time! He was a little guy, white with polka-dotted ears, and looked like the product of an italian greyhound and a jack russel, but with a curly tail. We ate our dinner on a cow-free ridge, and he stole our apple cores and probably scared some frogs away. Something to incorporate into the model! (Every time something changes or goes wrong, I joke that it needs to be incorporated into the model. Models are without limits! Infinite variables means it's accurate, right?)

We had a good night, spotting three species of glass frogs, an unidentified snake, a juvenile Rana warszewitschii, a giant fishing spider, and a marmosa (mouse opposum) that was missing most of a tail! A small swampy area on the side of a hill proved to hold not only tons of frogs but a large population of fish. I wonder how they survive the dry season-- mud burrowing?