What I did on my summer vacation, by Josie Chambers

I am just sending out an email to let you all know how everything is going in Costa Rica! I'm staying with a host family that consists of a mom, dad, five kids, cousin, rabbit, puppy, kitten, and 2 parakeets, so it can be pretty crazy at times in the house, but a lot of fun! My Spanish is already improving a lot, but I still have a lot more to learn. The family members are very friendly and patient with repeating phrases for me, and the 4 and 7 year old kids have already made me their "new best friend". The 17 year old taught me some salsa moves the other night!

I am working for a graduate student who attends Washington State (Meredith) and is doing her PhD research in evolutionary anthropology on the behavior & ecology of white-faced capuchin monkeys. Mark and Karlijn are the two other field assistants I am working with, and they are graduate students from Connecticut and Holland. The work has been very interesting so far and it's nice to work with such a wonderful group of people.

I have been working in Manuel Antonio National Park every day for two weeks now, and have learned to individually identify the group members of two different white faced capuchin troops in the park (26 monkeys total). There are 8 troops total that live within the boundaries of the park, but we are only focusing on three of the troops. Differentiating between the juveniles can be tricky, but it's amazing how many small differences you can use to tell them apart.

I have seen many interesting behaviors so far, and am learning more every day! We are collecting behavioral data on overall groups and individual group members for the three groups in the park that are the most exposed to humans to look at intragroup dynamics and individual behavior occurrences. We are especially interested in aggression as it relates to exposure to human food sources. Just in the past two weeks, I have seen multiple skin contacts between humans and individual monkeys, fur rubbing behavior with cleansing wipes stolen from tourists, and many cases of direct and indirect feeding of the monkeys by the tourists. On the second day of work, we noticed that one of the females of one of the troops had given birth overnight! There is also another female in the same group who is pregnant, and looks like she will give birth very soon. There are a total of 4 baby/infant monkeys right now across the three different troops we study, and they are very cute! I have recently established inter-observer reliability with Meredith, and am thus now able to collect data on my own through group scans, focal follows, and ad lib data.

I have also seen two cases of intergroup aggression between two different groups we are studying. When two troops encounterd each other, the females and juveniles faded deep into the forest while the males of one group banded together and chased after the males of the retreating group. After the initial chorus of aggressive vocalizations, the troops continued to stalk each other back and forth between one another's territory for the next half hour, constantly threat facing. The researchers I work with and I were split up in the forest, following different parts of each group and recording all information on a voice recorder.

One very interesting thing I have noticed is that one female from each of the groups we study, and an additional troop that lives near my host family's house has a distinctly dark colored crown. I have not seen anything about this in the capuchin books I am reading and am wondering if the crown reflects a dominant female position in the group. If so, if the appearance of the crown has a genetic component and/or is a product of hormone differences. I am not sure what is involved in measuring hormone levels across troop members, but am very interested in what the outcome would be between group members and groups with less or more exposure to humans. Combining behavioral and hormonal data could help determine if the presence of the crown has much significance to group dynamics, and potential differences in hormonal levels between groups more and less exposed to humans could shed light on possible impacts humans are having on the more accessible groups in the park. I am also wondering if the crown appears only among troops in this park, or more widespread. It is also possible that the dark crowned females are closely related, which could open up the way for interesting genetic and female dispersal studies. These would be additional projects from the one I am currently helping with, but could be very interesting!

My daily routine requires waking up early, eating a massive but incredibly delicious breakfast that my host mom makes for me, and then heading out to the park. My commute to the park in the morning takes about an hour and requires travel on foot, by bus, and by row boat! When we get to the park, Meredith tells us which troops we are each working with and we split up to find the groups. There have been days where I find a group in 5 minutes, and days where it takes 2 hours. Once I locate the group I am working with for the day, I perform group scans on behavior, and follow and record behavior on individuals and their nearest neighbors for 10 minute time periods at 1 minute interval. I note any additional interesting behavior I see, as it comes. The groups will often retreat behind cliff areas that we cannot easily reach on foot in the early afternoon, and we head home for the day. Once back to Quepos (the nearby town to the park), I enter my data in an excel spreadsheet/word document and then usually go back to my host family's house for dinner and spend time with the family and/or reading about capuchins at night.