Hughes Mentor:  Stephen Emlen

Department: Neurobiology and Behavior

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Professor Stephen Emlen

Professor Stephen Emlen came from a biological family; his father did organismal, ecological biology. But originally he wasn’t interested in this work, and became a psychology major at Swarthmore College. He was inspired by several lecturers and did undergraduate research in a physiological psychology lab. But it was a bad experience because of a lack of supervision. And although the results were published, he was not confident in the strength of the study and some of his beliefs about science were shaken.

After this bad experience, Emlen’s interests shifted to biology. He spent one summer as an undergraduate in the Rockies doing field research and got hooked. He had always enjoyed being outdoors, and although his research during this summer wasn’t very successful, it was a great experience.

He graduated as a biology major and went on to graduate school at the University of Michigan at Ann Arbor. Emlen wrote his thesis on the mechanisms of behavior of nocturnally migrating birds. During this time he attended grad seminars and discussed several influential papers and books that focused on kin selection and were re-evaluating altruism. He was very interested, and says that these theories “spoke to the core of me.” Emlen began doing social behavior observations during the summer when no work was being done on migration.

After graduate school several universities offered him positions. Animal behavior was a very newly emerging field and few places had any faculty teaching in this field at all. Cornell offered him a position, and he was interested because of the beauty of the surroundings and Cornell’s amazing reputation at the time for organismal biology. But the position wouldn’t have allowed him to teach what he wanted to and so he turned it down. Eventually Cornell came back to him and asked him what he would really like to teach, so he agreed to come.

Emlen first worked with Eisner to create Neurobiology 321, a course which covered both neurobiology and behavior, and which in some ways formed the basis for the Neurobiology 221 which exists today. At the time it was one of the only courses in the country that focused on behavior.

Professor Emlen has studied many different social systems and organism. He admits that it has been difficult to switch topics, both in receiving funding because of a lack of experience in the new topic, and in managing time between reviewing papers on topics that he used to study and focusing on his new research. Yet he also says that it has had great rewards for him as a biologist.

He also says that feeling that there are important applications to your work is crucial for maintaining your excitement about the project. One of the reasons why he switched from focusing on migration to focusing on mating and social behavior studies is that he felt that there weren’t any direct human applications of migration studies. In mating and social behavior studies, however, broad patterns can be found with huge relevance to human situations. In his experiences many people have been resistant to the idea that evolutionary biology and behavior studies can be applied to human behavior. Yet he is more motivated by this resistance.

Emlen loves doing field work, and although it took a long time to work out the details, spends some of his time in Kenya. He has been able to combine his love of the outdoors with his love of science and thinks that his career path has been a great choice.

When asked what he does for fun, he responded that the great thing is that there isn’t a big distinction between what he does for work and what he does for fun. He also enjoys the wilderness and hiking, and likes traveling and experiencing other cultures. His wife is an avid photographer and he enjoys working with her photographs and arranging for her to take pictures.

Hughes Writing Assignment: A day in the Lab

Junior and Laura build a house and have twins. When the kids are young George and Barbra stop by frequently to bring gifts for the children or to care for the youngsters while the parents tend to other things. Obviously the four adults are more then just casual acquaintances, but what is going on?

I am using the first family as an example of what the cooperative breeding birds that I study do. George and Barbra are Junior's parents, and the twins are the grand children. Exchange the word “house” for “nest” and replace the human names for the unique color combinations that identify each bird in the study, and this is no longer a story of the first family, but now is observations from a nest in a straggly tree in the arid savanna of Kenya.

The birds in the study are Grey Capped Social Weavers, a unremarkable bird visually, except the comic effect of a grey cap on a stout frame that makes the bird resemble a plump balding man. What the members of the species are remarkable for are there social lives, which, we have seen, can resemble our own. The kind of social structure that is shared between Humans and Grey Capped Social Weavers is one with extended family units, meaning multiple members of a family have children and raise them in cooperation instead of competition. Such extended family units are exceedingly rare in the animal kingdom, so any incidence of them being a part of an animal’s social system has the potential to tell us about how we became the social species we are. This is why the Emlen lab studies these birds.

We don’t yet know why Grey Capped Social Weavers evolved to be a social, but we do know that it is a trait, like big brains and being able to walk upright are traits, that is present in the population because it confers a benefit on the individuals that possess it. One idea for how being social benefits the birds is that because they live in a environment so harsh that very few young survive each year, and because having young is an large investment of time and energy, it is sometimes better to successfully to raise relatives then to have and lose offspring yourself. This is not the only explanation for the evolution of social behavior; another possibility is that helpers might be getting some hidden benefit, like secretly mating with one of the breeders. There is also the possibility of more complex foundation to social behavior, like reciprocal helping. Examples of this would be chimps grooming each other, or you lending your friend money. This is help that is given with the expectation of such behavior being returned in the future. The task in my lab is to figure out which mechanisms are supporting social behavior in Grey Capped Social Weavers.

To do this I use observations like the opening paragraph. Luckily, Grey Capped Social Weavers reproduce annually, and most become a breeder by two years of age, so a study of only a few years can capture many generations. With behavioral observations I can make a summary of a bird's social interactions (where it breed, where it helped, how much it helped). Gradually, using information from consecutive years, a social family tree can be made. This, combined with a genetic family tree that tells true parentage, provides the tools needed to begin to discern between the various explanations for sociality. When there is no more to gain from observations, or there is a hypothesis to be tested, experiments can be done to see an individual’s response to a change in its social structure. Such an experiment could involve removing a mate or eggs, and the result would have the property of supporting or refuting one hypothesis.

I am still doing the first stage. I use six years of data from four colonies and attempt to find the structure through the noise. Because a colony can have up to 220 individuals in it, this is a good deal more complicated then the first family example. People who take joy in finding patterns will be able to understand the appeal. It is an ultimate puzzle. The patterns here are not from a created mind game, but are truly unknown and waiting to be found. Having free reign in such untouched territory is exciting.

I got into the lab by excelling in an Animal Behavior class and Evolution classes. The way of thinking taught in those classes is necessary to succeed in my lab because without an understanding of the questions you won’t be able to find the data that answers them. The concepts taught in those classes will also be necessary when designing experiments for the field in the future. Interested students should also know that because of the nature of the study there is a great separation between the field season, which is the data collection, and work done in the lab, which is analyzing what was collected. This requires a level of patience difficult to maintain. The trade of is a wealth of data, and inclusion in a project larger then undergraduates interested in evolution or behavior usually find themselves in.

When the study is done we will better understand the evolutionary causes behind social interactions in birds, and this has the potential to tell us about the evolutionary causes behind our own sociality. Human society is full of detrimental social interactions, like crime and war, knowing more about how we got here is an important step to improving these problems in our society.

Meeting Stephen T. Emlen

What do jacanas, altruism, navigation, bee-eaters, communication, and avian social groups have in common? Professor Stephen Emlen. The Jacob Gould Schurman Professor of Behavioral Ecology at Cornell, he is an authority on animal social behavior, having explored everything from bird nocturnal migration to the costs and benefits of group living. Emlen obtained his undergraduate degree at Swarthmore College where he enjoyed close interaction with faculty, completed his Ph.D. in Zoology at the University of Michigan, and became a professor at Cornell shortly thereafter.

Although Professor Emlen’s research covers a wide range of topics and species, he has focused primarily on the adaptive aspects of social groups, which he became interested in during the 1960’s. “Ecology had been a field for a fair amount of time, but animal behavior was very different…it was very much a descriptive field in search of theoretical constructs until the 60’s, and I just happened to come along…I kind of came in on the ground floor…[when people were] addressing a whole new level of questions.” In addition, the majority of his research uses avian species, including bee-eaters, indigo buntings, bank swallows, jacanas, and social weaverbirds, as subjects. “I choose species…based on the question [we’re trying to answer]…they have to be practical, but there’s an emotional, aesthetic side to it [as well].”

When asked what he considered his most influential discovery, Emlen replied, “In terms of the impact, I suppose it would be developing a very broad conceptual model of mating systems.” Indeed, his model has worldwide applications, and accurately predicts mating systems across virtually every taxonomic group. However, he feels that another rich area is the evolution of cooperation and conflict in family groups, and predicts the development of a model to explain this aspect of social interactions within the next fifteen years. So what advice does this behavioral ecology veteran have for young people interested in the field? “It’s very important to have research experience…a lot of people are very attracted to working in the field…and that’s a wonderful first step…but it’s not all snazzy exciting adventures all the time…[you] have to really be interested in the conceptual issues…[and] research experience is critical.” As for undergraduates pursuing work in his lab, he stresses the value of intellectual curiosity. “The important thing is excitement about the area…[they must be] driven and curious…I look less at their grade point [average] and much more [at] their creativity and ideas.”