One of the first questions people ask me here or at home is what exactly I do when I come down to Panama. The answer to that question has been slightly different every year (this is my fourth trip down here), but it has all been leading to this current trip. The basic premise of my research is to study where animals move in the canopy of the rainforest and why. Repeated use of the same pathways has been documented for several monkeys and a few other arboreal (tree-dwelling) animals. I often refer to these pathways as “canopy highways,” which conjures up an image something like this:
In reality, it’s still unclear whether it is individual branches that are used over and over again, certain trees that align into a path, or just general areas of forest that are easier to move through than others. In order to investigate this question I started thinking about what is required for an animal to move through the forest canopy. The answer is actually pretty simple – in order to get from one place to the next without touching the ground, you need some sort of above-ground structure. By mapping the three-dimensional structure of the forest in relation to routes that animals have already moved, I thought it might be possible to characterize the type of forest structure that is most suitable for use as a canopy highway. For this, I turned to several of very generous collaborators, who provided data on the movement patterns of three different monkey species (howler, capuchin, and spider; pictured below).
Another collaborator also provided three-dimensional forest structure data collected by airborne LiDAR (basically the laser version of RADAR). The video below shows a visualization of these data.
After a whole lot of reading, thinking, troubleshooting, coding, pleading for help from my labmates, reading, fighting back tears of rage, I finally produced a few models that mapped areas most likely to be used for movement based on forest structure that look something (though not exactly) like this:
In this image the low, medium, and high probabilities of use are represented by green, yellow, and red, respectively.
Now I essentially have a map that I think shows where animals are least likely to go and where they are most likely to go based on the structure of the forest. This in itself is a feat that at one time I never thought possible – I’ve never had much of a knack for programming and had to learn how to use all kinds of new software, but alas, it happened! The goal for this trip is to test how well the model works in real life, a step that is often not taken in the ecological modeling world. I am setting up cameras in areas of predicted high, medium, and low use and to see whether my predictions actually line up with reality. It might work, it might fail miserably, but at this point I’m just excited to have the opportunity to try it out. It has been a long haul so far and there is certainly a lot of work ahead of me (I’m hoping to install cameras in 20-40 trees in 10 weeks!), but I’m excited to keep you all updated as the project progresses.
I’ve spent most of my days so far walking through the forest looking for trees to use (the Prospecting Phase, as I called it in my proposal). I’m planning to start climbing and installing cameras early next week. Wish me luck, I’ll keep you all posted!