By Avery Driscoll, Westminster College
Greetings from the Piro Station! We’ve spent the last week and a half here surveying for Neotropical River Otters along seven nearby rivers. Besides the work of the Round River crew over the previous two semesters, little research has been done on the Neotropical Otter in Costa Rica. Our goal is to collect all the data we can about otter habitat preference by looking at how otters use diverse river systems on the Osa Peninsula.
Collecting data on transects within the Bijagual River. Photo by Shalynn Pack.
Most days have begun bright and early with a 7am ride to each river with our favorite colectivo driver, Tuto. We survey for at least two kilometers upstream, recording data every 150 meters about variables such as river width, depth, slope, canopy cover, and the number of places an otter could scat, leave tracks, or use as escape shelter. When we find tracks or scat—both telltale signs of otter use—we also record details about the substrate it’s located on, the number and age of the tracks or scat, and the composition of the scat. We were able to set five game cameras at frequently used sites, which will hopefully capture more details about the otter’s use and behavior.
A crustacean-filled otter scat, on a perfect scatting log. Otters use their scats to communicate their territory to others. Photo by Shalynn Pack.
By far, the highlight of the surveys was spotting one of the elusive river otters on the Cayunda River. Shay spotted the otter sliding under a rock outcropping just ten feet away as we were nearing the end of the day’s survey. We were able to get a great look at the otter, which was surprisingly graceful and predictably adorable. It slid out of the den, into a deep pool, and surfaced, looking straight at us before swimming away downstream. We are now done with our surveys at Piro, but plan to collect data at three more rivers towards the end of the month.
There has certainly been no shortage of incredible wildlife! We have a resident Nine-Banded Armadillo, who we hear wandering through the underbrush right next to our tents most nights. Chris has been our trusty tracking guide, helping us identify a number of interesting tracks including Tapir, Puma, Paca, Crab-eating Raccoons, a Mouse Possum, and even Jaguar. Other notable inclusions on the cool animal sightings list include Squirrel and Howler Monkeys, a Northern Tamandua Anteater, a Tayra, a Boa Constrictor (Jori’s favorite), Coral Snakes, Green Vine Snakes, Army Ants, baby ringed kingfishers in their nest, Scarlet Macaws, King Vultures, and plenty of Coati and Agouti.
A Northern Tamandua climbs through the vines in search of ants. Photo by Shalynn Pack.
A local researcher brought us to see our first jaguar tracks! This track is from a small jaguar, one of only an estimated 40-50 in the region. Photo by Shalynn Pack.
In addition to our long days in the field, we’ve managed to fit in both academics and fun. We’ve gotten our first taste of the meticulous process of “Grinnelling”, which involves compiling very detailed notes about all of the day’s observations and events. It has also tested our (mostly poor) drawing abilities, quickly revealing that CeCe is the artist of the group. We have discussed the significance of natural history, the history of conservation in Costa Rica, the basics of tropical ecology, and the efficacy of the Costa Rican payment for ecosystem services system. We also all survived our first natural history quiz, which required us to be able to identify about forty species of local birds and plants.
A 1.5m long boa eyes us suspiciously before retreating into the forest. (Don’t worry, Shalynn Pack took this photo with a long zoom lens!)
Sunday was a much-needed day off. We spent the day relaxing, swimming, and exploring at the beautiful Matapalo beach.
Students relax at Matapalo beach.
We said goodbye to our instructor Shay last night, who unfortunately could only be with us for our first couple weeks. Tomorrow, we are taking the colectivo back to Puerto Jimenez for a brief stopover before heading out to a station at Lomas del Sierpe where we will be doing bird counts. We will miss our friends at Piro (especially the Armadillo!) but are looking forward to a change of scenery—and clean laundry! Pura Vida!
Walking home to Piro Station after a long day hiking up the River. Photo by Shalynn Pack.
