I’ve finally made it out of the the USA. After two flights, a VERY long immigration line at the airport, and two and a half more hours in a bus through the mountains of Costa Rica (which was simultaneously beautiful and sickening), we arrived at La Selva Biological Station on Monday around 7 PM. At this point in the day time barely felt real, and this feeling was further exaggerated by the fact that it was already completely dark when we arrived. This sharp contrast in the length and time of daylight that I am used to and that of Costa Rica reminds me of an overused quote from the Wizard of Oz.
All cliché references aside, in the six days that I have been here I have been astounded by the many differences between wildlife here in Costa Rica and back home in America. Aside from the obvious differences in fauna such as the primates and myriad species of tropical birds, there are so many different species of flora than in the states. Not only are there different species here than there are at home, there is so much more variation in the species that you find. When you enter the forest, you are met with a seemingly infinite green and a new species of everywhere you turn. While one of the books that we read before coming here, Tropical Nature by Forsyth and Miyata, mentioned this feeling of being overwhelmed by green when you enter a tropical forest for the first time, reading about it did not prepare me for the reality of entering the forest for the first time. It’s almost too much diversity to be able to distinguish anything at first, but with the help of the awesome guides here at La Selva I have been able to learn a lot about the wildlife here and how to find them in the dense forest.
On our first full day here, we began with a guided hike through the second-growth area of the forest closer to the biological station. A second-growth forest is a forest that has been regrown after being cleared for various reasons. The oldest area of this secondary forest has been growing for about 50 years, and the newest has been growing for about 15. In this area, the canopy is not as dense and light is able to reach the forest floor. Here, we saw “blue jean” poison dart frogs (shown above), two-toed sloths (which can be distinguished from three-toed sloths by their brown coloring), termite nests, orchid bees, a male great curassow, and a family of tent bats!
In my opinion, some of the most interesting creatures that we learned about while on the hike were leaf cutter ants. I already knew a little about these ants, mainly just from what their name implies, but I did not know the intricacies of how they function. Basically, they create these superhighways using pheromones that allow all of the ants in the colony not to get lost, and they use these highways to go all the way up into the canopy, cut leaves using their mandibles, and then carry the cut leaves back to their colony. Here is where things get even more interesting, though, because they don’t actually eat these leaves. What they do is they place the leaves in a special “room” in their colony, mix them in with their saliva and feces, and farm the fungus that grows on these leaves. They then cut the fungus up and feed it to their larvae. They also do not eat at all after their larvae stage, and only live for about two weeks, aside from the queen. In addition to this complexity of their food system, there are multiple castes of ants in the colony. There is the queen and workers, of course, but there are also bodyguards who basically just patrol the highways that the workers move along and clear any debris in the way as well as ward off competition that may be trying to interfere with their leaf mining operation. There are also minima, the smallest of all of the leaf cutter ants, which I believe have the job of operating inside of the ant hill and tend to the larvae, feeding the fungus to them.
Going back to our day, we then went into the old-growth forest, which is older and more dense than the second-growth part of the forest. We saw some more wildlife here and learned about why there are different types of flora in older areas of forest. That night we went on another hike guided by the same guides, and we saw some millipedes, a fer-de-lance (a very venomous snake), and some other things that I’ll save until another blog post to talk about.
On the second day, a worker named Kenneth talked to us about the history of La Selva and OTS (Organization for Tropical Studies), which La Selva is a part of. Later in the day, during an activity where we attempted to calculate a rough estimate of species diversity in the forest area near our classroom we encountered our first group of howler monkeys, which was a really cool experience. A passerby with a nice camera showed us how to do the howler monkey howl, and they started howling back at us when we did it. Being so close to the wild primates was a pretty surreal experience for me especially since I have never seen one in person that wasn’t in captivity. They looked so free, traveling around the canopy so smoothly and naturally.
On the third day, I met with Dr. Wasserman and Dr. Libby to discuss my ideas for my research project for the month, and through this meeting was able to hone my ideas into a tangible research proposal. I will wait until next week when my research is fully solidified before talking about it here. We also started prepping for the howler monkey census which took place on day four.
The next day, we split up into about 25 groups of two, woke up at 1:45 AM, hiked about 2 miles into the woods, and stood in one place with our partners from 4-7 AM, recording when and approximately from where we hear the groups of howler monkeys. The idea of this is was to combine all of the groups’ data to get a good estimate of the number of howler monkey groups that are in the forest and then compare that number with the results of a study that took place at La Selva in 1992 and had the same methodology. We also presented our research proposals to the group in order to decide who we could pair up with to do conduct our actual projects.
And that takes me to today! I am writing this on Sunday the 29th of May, and I am looking forward to what this upcoming week holds for us.
Until next Sunday,
Tate
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