Thoughts on Theses: Joely DeSimone
Issue   |   Wed, 10/01/2014 - 02:07

Q: What is your thesis about?
A: I am studying the causes and effects of parasites, specifically blowfly larvae, on nestling birds. My three major objectives are to see the nest characteristics that predispose nests to parasites, the effects blowflies have on growth and development of birds, and whether blowflies stimulate an immune response from birds. I spent a couple months this summer in the College’s bird sanctuary with my adviser, professor Clotfelter, and two SURF (Science Undergraduate Research Fellows) students, Tiffany Lee ’16 and Lindsey Bechen ’16.

Q: How did you become interested in this topic?
A: I became interested in doing fieldwork as a thesis when I went to Costa Rica for Professor Clotfelter’s Seminar in Tropical Biology class. I was excited about working with my advisor and being outside to conduct field work rather than lab work. Professor Clotfelter had worked with tree swallows before, so the SURF students and I were picking up where he had left off. Since I had never worked with birds before, he helped and taught me about the procedure and how I should approach this thesis topic.

Q: How did you conduct your fieldwork over the summer in the bird sanctuary?
A: We went out to the bird sanctuary everyday for several hours. At the beginning, we were checking to see when the birds laid their eggs. Two weeks after that, we would return to the nests every three days to check the nestlings and their growth. We took their blood on certain days to measure their hemoglobin. Later on, we also conducted immune tests.
In the field, we had to do extensive work to account for control variables. One example is that parasites might be the main factor in abnormally small nests, but we didn’t know if they were also small because they weren’t being fed enough, so we had to conduct a feeding observation of the parents to see how often they fed their babies. Also, there was a bird sucker contraception that helped us get an idea of how many insects were available in the area.
There are 60 bird boxes out in the sanctuary with tree swallows in them, and each nest had five babies, so we were checking on a large number of birds during the fieldwork. I definitely needed my adviser and two SURF students’ help with data collection.

Q: What were some characteristics of the parasite (blowfly larvae) that you observed? What other observations have you made?
A: The blowfly larvae live within the nesting material, so we only sometimes saw them if they were clinging to a nesting while we worked with the nestlings. After the birds fledged the nest, I shipped the nests to a parasitologist at the University of Utah and she identified and quantified the blowflies for me.
I’ve collected most of my data, but have not yet started sorting through it and analyzing it. I predict that warmer nests will have more blowflies — other researchers have found that blowflies tend to like warmer nests. Both the structure of the nest and the direction that the nest box entrance faces contribute to nest temperature, so I’m going to look and see if there are any relationships among these factors. Some authors have found that blowflies increase nestling mortality and lower nestling body mass and wing length, but others have found no effect of blowflies on nestlings’ growth and development, so I’m excited to see what our results show. Parasitized nestlings are usually significantly anemic, so I measured the nestlings’ hemoglobin levels to quantify this piece of their fitness.

Q: When you were not collecting data in the bird sanctuary, what other work were you doing?
A: I was reading research papers when I wasn’t at the bird sanctuary, but it was tricky because we had to design our experiment as we were out in the field since we had to start soon after Commencement. There was a little bit of lab work for the birds’ blood that we collected, but it was mostly field work.

Q: What has been your favorite part so far?
A: The fieldwork has been my favorite piece so far. It is really fun to be out in the field, and working with the birds so closely made me become very invested in them. Also, reading papers about them has been great because it continues to confirm the close connection I feel to birds.

Q: Is this an area of interest that you would like to pursue after graduation?
A: I think that I will be going into public health, but this is still vaguely related in that the study of effects of parasites can be extended to diseases.

Q: What is the most difficult thing you came across during your senior thesis?
A: I think the tricky part was figuring out what to study while simultaneously conducting the fieldwork. For example, at one point, the two SURF students and I were not sure about how to do the immune test on the birds. Also, we decided to carry out an experimental manipulation where we sprayed bug sprays on a selection of nests to set aside some nests that would not have parasites. However, we had no idea how many blowflies were in the area, if nests would even have them or if they would be completely infested with hundreds of them.

Q: What is the most valuable lesson you have learned so far?
A: I’ve learned to take this project one step at a time. I tend to get overwhelmed by large projects with distant deadlines, but I’ve learned — and my advisor has helped in this regard ­— to break it down into week-by-week pieces, which makes it all manageable.

Q: Where do you stand in terms of the timeline?
A: I wrote most of my methods section over the summer while it was fresh in my mind and I just started writing my introduction section. My schedule is to be done with the introduction by the end of the semester.

Q: Do you think you were well prepared to write the thesis?
A: I think the science classes I’ve taken at Amherst have prepared me to write with a scientific tone and precision. I’ve also read a lot of scientific papers for classes, which helps with both the research and writing aspects of a thesis. I think enthusiasm for the topic is equally important. A thesis is much easier to work on if you are invested in your research topic.

Q: Do you have any advice for future thesis writers?
A: Generally for all majors, you need to be really invested in the topic you are researching because you spend so much time on it. If you are not interested in the topic, it’s really difficult to continue writing and spending a large part of your senior year writing the thesis.