At the Crossroads: An Interview with Interdisciplinary PhD Julia Greenberg
If you’re anything like me, you fell in love with nature and the basics of biology before you decided to work in conservation. The elegance of evolution and the fascinating diversity of animal species and animal behaviors had you hooked – and then you learned what humans have done to the natural world and decided to work in conservation. If this sounds familiar, you might also have felt torn between interest in pure scientific research and searching for solutions to today’s problems. Fortunately, there is a solution. Fields such as conservation behavior and conservation physiology are at the crossroads between pure biology and applied science.
Julia Greenberg, a PhD candidate in Kay Holekamp’s research group at Michigan State University (MSU), works at these crossroads: conservation behavior and physiology. She is utilizing these two fields to better understand how spotted hyenas (Crocuta crocuta) in Kenya’s Maasai Mara are coping and adapting to environmental change through the MSU Hyena Project. Julia initially began her career in research by primarily studying primate cognition, working at the Lester E. Fisher Center for the Study and Conservation of African Apes After and the Max Planck Institute for Evolutionary Anthropology in Leipzig. Recently she made the leap from studying primate cognition to conservation behavior and physiology in hyenas. After hearing Julia give a lecture at Lincoln Park Zoo, I decided to interview her to find out more her current work and the path that led her to her research.
How do you define conservation behavior and conservation physiology?
These fields lie at the intersection of basic and applied science. Both focus on how the behavior and physiology of organisms are shaped by environmental changes and disturbance as well as how knowledge about the behavior and physiology of organisms can be utilized to address applied conservation problems.
What made you interested in conservation behavior and physiology?
My interests have always been interdisciplinary and at the intersection of basic and applied questions. I think these qualities make these fields a good fit for me. They require me to integrate information from multiple fields, apply methods from different disciplines, and take into account the real-world implications of my findings.
Can you give a brief overview of your research?
I am interested in how the behavior and physiology of organisms are shaped by environmental change. I am also broadly interested in social behavior and the development of behavior and physiology during ontogeny. Both developmental and social processes may afford individuals flexibility in adjusting to change but may also act as constraints. I believe that understanding these processes will not only help us to predict adaptive and non-adaptive responses for conservation purposes and to understand population-level patterns but also to answer fundamental questions in behavioral ecology.
Spotted hyenas make an excellent model system in which to study mammalian responses to environmental change due to their remarkable flexibility. Dr. Kay Holekamp and the MSU Hyena Project have documented behavioral and physiological changes in adult hyenas that are associated with increased human disturbance. We can study these changes by conducting: 1) longitudinal analyses of how our study populations have changed since our project began in 1988, and 2) cross-sectional analyses of hyenas living in areas with different degrees of human disturbance.
In my dissertation research, I am exploring how the spotted hyena’s unusually protracted developmental period helps to shape this flexibility. Specifically, I am testing the hypothesis that spotted hyena females transmit information to offspring about environmental disturbance through maternal effects. I predict that the temperaments and life history trajectories of young spotted hyenas are shaped, in part, by maternal behavior and stress physiology. I also hope to shed light on whether such maternal effects may serve an adaptive function and be one of the mechanisms underlying hyenas’ ability to exist in a variety of habitats and adjust to changes in their environments.
To test this hypothesis, I am integrating several approaches including behavioral observations of mothers and cubs, GIS analysis of maternal space use, field experiments to assess cub temperament, longitudinal analysis of changes in life history patterns, and assays to measure concentrations of faecal glucocorticoid (stress) hormones.
What made you interested in studying hyenas and their response to urbanization in the first place? Were you interested in how wildlife reacts to urbanization and increased human disturbance and environmental change in general, or were you specifically interested in how Africa’s most flexible carnivore is dealing with increased environmental change?
Applying to graduate schools, I saw spotted hyenas as a potentially great model system for examining questions of how animals respond to environmental change. I was intrigued by findings from previous work in my lab that adult spotted hyenas were showing behavioral and physiological changes in response to increased human disturbance, but no demographic decline as we suspect has occurred in sympatric carnivores.
I am also particularly interested in development and spotted hyenas have some interesting features of their life histories. They have an unusually protracted period of development relative to other carnivores and show pronounced maternal effects. These two features combined made me interested in how such flexible responses might be shaped during their long developmental period and what generalizations we might be able to draw from understanding these mechanisms.
Why did you decide to pursue your PhD? And what was the application process like for a PhD on such a high profile species? Would you recommend that students interested in pursuing their PhD do anything in particular to prepare to apply for and undertake their PhDs?
After college, I knew I was interested in research and would likely pursue a PhD, but I wasn’t sure in what field. So, I took time off from school to explore my interests, which is something I always highly recommend to undergraduates interested in graduate school. Once you get into grad school, it is a long path and in my experience, folks who take some time away from school enter a graduate program more confident they want to be there, they are more likely to be doing it for the right reasons, and they are a bit more mature at dealing with the challenges it presents.
In my case, I received a Fulbright Fellowship to conduct research on animal cognition in Germany. This gave me the opportunity to live in Europe, something I had been interested in doing, gain more hands on research experience, and explore what field I might want to pursue. In terms of the graduate school application process, I think it is important to recognize how different it is than the college application process. The most important factor, I believe, is your fit with your advisor. So, it is important to contact potential advisors and begin a conversation about your interests, their research program, and what you might be able to do with them. I think I a lot can be gleaned from interacting with potential advisors over email, through visits, and by chatting with their students, and often, you should trust your gut as to whether a person’s lab would be a good fit.
From what I know about your career in the path, you have mainly been involved in work with primates. How did you make the switch from studying cognition in apes to studying behavioral flexibility in hyenas?
During my research after college in the field of primate cognition, I realized that I was more driven by my research questions than by the particular species. I became interested in getting exposure to research outside the primate world and realized that I did not want to be pigeon-holed as a “primate person” for my entire career.
In thinking about embarking on a PhD, it was also clear to me that studying a non-primate could offer some logistical benefits if I wanted to look at developmental processes as primates have such a protracted period of growth. I was drawn to spotted hyenas, not only because of the questions I could ask using them as a model system of behavioral flexibility, but also because they share so many behavioral similarities to primates. Their social system is far closer to that of Old World Monkeys than to other carnivores. I found the hypothesis that spotted hyenas and such monkey groups have undergone convergent evolution fascinating and it was attractive that I would be able to draw from what I knew about primate behavior when studying a different species.
What have been the best and worst parts about working towards achieving your PhD? And (I know this is an awful and dreaded question, but I have to ask) what do you think you’ll do once you’ve been awarded your PhD? Will you continue to work in research or will you try something new?
I think one of the hardest parts of working towards a PhD is the lack of structure, especially in the later years. With no one “telling you what to do” it is often up to you to structure your time and decide on your priorities. Research is slow so it can often feel like you are making little progress and you often hit dead ends.
Long-term, I would like to work on basic and applied research topics at an NGO, a governmental position, or a zoo. I am interested in continuing to conduct research, but am also potentially interested in jobs that allow me to also work on topics in management, education, communication, and outreach—ideally I will be able to find a job that allows me to do all of these things!
When you are out in the field, what is your day like? And What is the most interesting thing/best thing you’ve done in the field for your research?
I feel fortunate to have observed many fascinating dramas in the lives of the spotted hyenas we study and I think that observing them make decisions, develop, and navigate their social world is endlessly interesting. However, I’d also say that milking hyenas is one of the coolest things I’ve gotten to do as part of my job and attending the wedding of a Maasai friend in Kenya was one of the most interesting experiences I’ve had.
How do you think your research will benefit conservation efforts? I don’t know if this is a very good question…are hyena’s really endangered? Or will your research help scientists understand why some species are better at adapting to environmental change than others?
It’s a good question, but also a hard one to answer. I believe that no single study by itself often shapes science or management very directly (and this is probably a good thing!) but I hope that the research I’ve conducted as part of my PhD will contribute to a body of evidence regarding various basic and applied questions.
For example, we have a much larger body of literature documenting the effects of urbanization on birds and small mammals, but relatively few on this topic in large carnivores. I hope that if others read my results in this area, they might be inspired to conduct similar work in other large carnivores and over time, hopefully general trends will emerge that we can use to more tangibly direct management or strategies to mitigate human-carnivore conflict.
Similarly, my work looking at the fitness implications of elevated stress hormone concentrations in early life for spotted hyenas by itself likely has little importance to conservation. However, there is a fundamental question that has not been answered regarding whether the non-invasive stress hormone monitoring that scientists and managers often invest money and time in can actually be used to project population trends. As more longitudinal studies on long-living mammals continue to be conducted year after year, hopefully this is a question that we can ask in many species and hopefully there will be some general trends that emerge.