By Avery Driscoll, Westminster College
This week we survived our conservation biology exam, became certified experts on the flora and fauna of the Osa (just kidding–that would take several lifetimes), and at least semi-successfully produced papers from the fieldwork we’ve been doing this semester (Editors note: The students did an awesome job on their papers). Somehow, we also managed to fit an evening turtle patrol, a hatchling release, and a much cooler-than-expected visit to the “bat tree” into our busy finals schedule.
Our first day of finals included an essay about how our views of wilderness and conservation have changed throughout the program, which required some serious reflection on our academic and fieldwork experiences. While none of us were thrilled to write the essay, it did provide a much-needed opportunity to step back and relate our incredible experiences to the big picture of conservation.
Piro beach; where we wished we were instead of studying for finals. Photo Scott Braddock
Day two brought a very full day of data analysis and paper writing, as we attempted to make sense of our data and distill results into scientifically relevant discussions. With a lot of help from Chris, I think I learned more about applied statistics in a day than I did in my semester-long stats class. Jori wrote about the bird point counts we conducted in Lomas, I focused on the results of our River Otter surveys, and Cece tag-teamed both projects, writing portions of each paper.
Jori and Cece determined the densities of seven bird species at Lomas, including the Great and Little Tinamou, the Crested Guan, Baird’s Trogon, the Red-Capped Manakin, the Black-Faced Ant Thrush, and the Streak-Chested Ant Pitta. By comparing our densities to previous studies, they found that densities for these species are mostly higher now than they were previously at Lomas or at Piro. In general, they found that the time of morning, distance to the road, and distance to the river did not strongly affect bird densities. These differences in densities could indicate that bird populations at Lomas are recovering, possibly due to reduced hunting pressure, or they may reflect changes in season or climate.
Throwback to a Forest Falcon at Lomas
In our analysis of otter data, Cece and I found that scat and tracks, which are commonly used in studies as a proxy for otter use, are somewhat biased indicators of because they are fairly strongly correlated with the number of rocks, logs, and sandbars available to otters. We also found that otters prefer deeper river segments, but that river width, slope, canopy cover, shelter availability, and land use surrounding the river surprisingly did not affect otter use. Finally, we found that otter’s diets are different between rivers, indicating that prey availability may differ from river to river.
On day three, we celebrated the completion of our final Grinnells as we compiled species accounts for one local plant and animal based on our observations throughout the semester. We also had a more traditional exam for our Conservation Biology class, covering material from our lectures and readings. We took a break from studying to go find the “bat tree”, which was apparently a common place to find vampire bats, a species that feeds on the blood of mammals. We found the huge, hollow Ajo tree off of one of the Piro trails, but the entrance to the tree-cave was being guarded by a meter long Fer-de-Lance. We crawled into the tree very carefully so as to not disturb the snake, and could see well over a hundred bats of several different species roosting and flying around inside.
Fer-de-Lance by the entrance of the bat cave.
Bats roosting inside the tree. Photo Scott Braddock
In the evening, we were lucky enough to tag along on a magical nighttime turtle patrol. We left for the beach around 8pm during a true downpour in the hopes of spotting and tagging a mother turtle while she was laying her eggs. We didn’t see any turtles on our first pass down the beach, but enjoyed watching the bioluminescence in the waves, which glowed blue as they crested and crashed. On our way back, Cece spotted fresh turtle tracks illuminated by the lightning and we found a turtle just beginning to dig her nest. Sea turtles enter a sort of trance state while they are laying eggs, during which they don’t feel pain and are unbothered by people. We were able to kneel around the turtle and touch her shell as she nested, and watch Emily and Manuel tag both front flippers. She used her rear flippers to kick sand over the finished nest, and spent about ten minutes packing down the sand and camouflaging the area before walking back into the ocean.
Manuel with Osa Conservation tagging a mother Olive Ridley Sea Turtle while she lays her eggs. We use red light to avoid disturbing the turtle. Photo Scott Braddock
Day four was back to work finalizing our papers, which Chris had offered extensive feedback on. While the process was long and challenging, it was rewarding to follow the process through from fieldwork to finished paper. We also got to take part in a turtle hatchling release that afternoon, which involved releasing about 60 squirming baby turtles on the beach and guarding them as they made their first journey to the ocean. Click the link below for a short video clip of this amazing experience! Be jealous.
Early the next morning we finished up our final natural history quiz, and after a sad goodbye to everyone at Piro and our fantastic hosts Miguel, Bonny, and Maikol, took the colectivo back to Puerto Jimenez for an evening of errands and relaxation. Today we’re off to the base of Chirripo, the tallest peak in Costa Rica, for a celebratory end-of-semester hike! Pura Vida, still.
*Title creds to Jori