March 20, 2018
Our day started with making a delicious smoothie… for butterflies! In case you didn’t know, a butterfly’s favorite smoothie consists of smashed up banana, pineapple, papaya, and beer. While some of us were preparing this for the butterflies, our fellow adventurer Theo learned how to sharpen dull machetes with some of our lovely hosts. When the smoothie making was complete, we broke into groups and headed out to set up butterfly traps in varying habitats around the field station.
Here is a little step by step to set up a butterfly trap: (1) Tie a carabineer to rope and pray to the ecology gods that it will catch on the branch you are hoping to throw it over. (2) After successfully “finagling” the rope over the intended branch (or settling for any branch you can get!) detach the carabineer and tie the top of the trap to the rope. (3) Place a rain fly over the trap to protect the butterflies in case it rains. (4) Ants tend to also be interested in our butterfly bait, and surprisingly, they can actually kill the butterflies themselves. To counteract this, apply Tanglefoot (a sticky paste that brings ants to an equally sticky end) to the rope holding your trap. (5) Put a bowl of butterfly smoothie bait on the base of the trap. (6) Hoist up your trap and hope for the best!
While setting up our traps, one group had a chance encounter with some local furry inhabitants. While struggling to throw rope over a branch, we heard some loud rustling in the forest above us, and before we knew it, two coatis raced across the path directly in front of us!
Our goal was to be able to use the mark-recapture method we learned about in class. In this case, this consists of capturing a butterfly and marking its wing with a Sharpie, then releasing it. After some time, we check the traps again and record butterflies that have already been marked and new ones that have found their way into our traps. From this method, we are able to estimate population size and some basic measures of diversity. Because of butterflies’ distinctive wing patterns and colors, they are fairly easily identifiable with a basic morphology guide. After the traps were up for several hours today, we were disappointed when we checked them and found them butterfly-less; however, we are hopeful some will be drawn to the expertly crafted smoothie we prepared for them by the time we check again tomorrow.
While we waited for our traps to fill after setting them up, we took a break from trekking around the rainforest to look at some of our data from yesterday on leafcutter ants. The biomass we collected from the ants had been drying in an oven overnight, so we took it out and weighed it by group. Then we had a brainstorming session on the best way to represent our data. After recording it in Excel, Cathy led us through the steps to create a basic mathematical model that would allow us to estimate the total biomass removed by leafcutter ants in the Firestone preserve in one year. We used data from a previous study that estimated 101 ant mounds on the property. This combined with the data we collected allowed us to predict that leafcutter ants may be removing around 10,750 kg of biomass per year!
Some of us ended the day with a bumpy trip in the back of Cathy’s rental car to the top of the field station, with an elevation gain of about 1,000 feet. On the way, we encountered an unexpected form of wildlife: a domestic horse. It trotted in front of us for several hundred meters, and then disappeared into the rainforest. Once there, we checked the last 6 butterfly traps (finding them empty, of course). Driving along the top, were surprised to see several peccary leap in front of the car as they ran downhill.
We ended our excursion with a tranquil view of the hills rolling down to the Pacific Ocean, and the persistent call of an unidentified bird in the trees above us.
Sarah and Juliette