The focus in my lab is on animal behavior. The concept that drives our research is conflict, particularly sexual conflict. But our research touches on a wide range of behavior, including courtship, mate choice, dominance and aggression, sexual coercion, sexual selection, evolution and the hormonal basis of behavior.
In recent years, there is a growing understanding that sexual conflict between males and females is widespread among animal species, and can lead to evolutionary changes separate from those arising from traditional forms of natural selection and sexual selection (the latter involving male-male conflicts for females or females choosing males with preferred traits). At its roots, this conflict arises because males and females rarely invest equally in their offspring (e.g., the differential costs involved in producing eggs and sperm or the amount of time and energy involved in parental care). Moreover, as most species do not form lifetime pair-bonds, conflict also arises in from the fact that investment in current offspring often reduces the ability to invest in future offspring, particularly for females. Manifestations of this conflict can be subtle or more overt.
Examples of the latter include species in which females eat their mates even as they copulate or species in which males physically force copulations on females; male coercion of females is far more common than the reverse. In one school of thought, it has been proposed that female resistance to coercion may actually serve to screen males, allowing only more preferred or stronger males to inseminate the female. Thus, it is suggested that females may benefit from such a system (in terms of traits their offspring inherit). Others, however, have argued that the direct costs to females of overt male aggression, in terms of injury or loss of reproductive output, outweigh any benefit to her offspring. Likely, both scenarios occur in nature, but which predominates and whether patterns arise depending on the overall life history and mating system of the species are entirely unknown.
In our lab we study conflict using mallard ducks, a species in which sexual coercion in the form of forced copulation is common, and whose basic behavior and physiology has been fairly well studied. Briefly, mallards court and pair during the fall and winter months, where the highly ritualized courtship displays usually occur on water and in groups involving multiple males and at least one female. Copulations can occur at this time even though the birds are not fertile. Following pair formation, males tend to guard their mates, which is thought to benefit females by allowing them to increase their foraging rates, which in turn increases their nutrient reserves for the spring breeding effort. During the breeding season, mate guarding may primarily protect females from forced extra-pair copulations (FEPC), which can negatively impact female reproductive success. Unlike many species, female waterfowl do not appear to solicit extra-pair copulations, so all extra-pair copulations during the breeding season are forced. Note that males have two options open to them for siring offspring: consensual copulations with their mate, and forced copulations with extra-pair females. By studying the mating system as a whole, including the hormones underlying aspects of mallard behavior, we can better understand the nature of sexual conflict and how it is manifested in species with complex social and mating systems.
Students work in my lab in a variety of ways, but foremost, we work as a team. Also, you have the choice of helping others with their projects if you just want to see if this kind of research is for you, or working on your own independent study or thesis. Students work together to capture and individually mark ducks in the fall, observe and record their behavior throughout the academic year, and collect blood samples for hormone assays. Data on pair formation, dominance interactions, mate guarding and forced copulation are usually taken for use in multiple projects. Additionally, specific projects may require additional data, experimental setups or video recording for later analysis in the lab. Hormone assays are also conducted in my Upham Hall lab.
*indicates UWW undergraduate author
Smith*, S. M. and Davis, E. S. 2008. Clicker increases resistance to extinction but does not decrease training time of a simple operant task in domestic dogs (Canis familiaris). Applied Animal Behaviour Science, 110: 318-329 (doi:10.1016/j.applanim.2007.04.012).
Kime, N. C., Whitney, T. K., Davis, E. S. and Marler, C. A. 2007. Arginine vasotocin promotes calling behavior and call changes in male Túngara frogs. Brain, Behavior and Evolution 69:254–265.
Marler, C. A., Trainor, B. C. and Davis, E. S. 2005. Paternal behavior and offspring aggression. In: Current Directions in Psychological Science 14(3): 163-166.
Davis, E. S. and Marler, C. A. 2004. c-fos changes following an aggressive encounter in female California mice: a synthesis of behavior, hormone changes and neural activity. Neuroscience 127: 611-624.
Davis, E. S. and Marler, C. A. 2003. The progesterone challenge: steroid hormone changes following an aggressive encounter in female Peromyscus californicus. Hormones and Behavior, 44: 185-198.
Davis, E. S. 2003. Mate guarding. Interpretive Birding Bulletin 4(2): 20-22 (invited paper).
Davis, E. S. 2002. Male reproductive tactics in the mallard, Anas platyrhynchos: social and hormonal mechanisms. Behavioral Ecology and Sociobiology 52: 224-231.
Davis, E. S. 2002. Female mate choice and the benefits of mate guarding behavior by male mallards. Animal Behaviour 64:619-628.
Davis, E. S. 1997. The Down-Up display of the mallard: one display, two orientations. Animal Behaviour 53: 1025-1034.
Every applicant for a faculty position in this department must submit a teaching statement, usually called a statement of teaching philosophy. (As my undergraduate major was in philosophy, I take some issue with that term, but that is another discussion.) With some trepidation, I began my statement with a mock quote that may be familiar to you. “Why do we need to know that?” Whereas this question can be annoying and short sighted at times to those of us on the receiving end, it is more justified than many people realize. And it is a question I keep in mind as I design and constantly redesign my courses. No course can cover everything, so why, indeed, do I choose to include some material and exclude others? There are, of course, a variety of reasons that come into play for any specific piece of content and the course as a whole, but there are overall two seemingly conflicting approaches that drive my ‘answer’ to that question, and which I try to balance in my course design. In the end, I hope my courses help you to become a solid, rational but creative thinker, one who will be better equipped to honestly and fully evaluate all that life throws at you once you leave here, and make wise, well informed decisions in your job and your relationships with others and our Earth.
I often try to think of the concepts and skills that I can reasonably expect an intelligent person to retain years after graduating, and build my courses around them, using the course content as the substrate. For most people it is the broad ideas and ways of approaching problems and information that are retained rather than the many specific details that make up a course. The broader concepts however are often that last ones that students really tangle with, as they struggle to first master the details of the course. Details are important, however, (see next), and the great struggle for me in all of my courses is finding the right balance between learning basic content and having the time to get really messy with it. By the latter I mean working with content to develop a deep understanding of life processes and patterns, pulling material from within the course and without to create that understanding and developing a logical and skeptical (in the good sense) approach to your courses and your life.
I suppose I could just make a list of the larger concepts in each course, and be done with it all in about a half-hour. But that would be meaningless. You would then only learn such concepts as you learn small details, and not have any way of justifying the validity of those concepts to yourself (or anybody else, for that matter). Moreover, you would not develop any of the very important critical thinking skills that are so important in science and life. It is really only by studying the details that broad patterns can be discerned and inconsistencies found that can lead to new insights. Again, the challenge for me is to find the right balance so that students have time for both. Of course, the real work must be done by you.
The following list includes presentations given by students in my lab at off-campus locations, and so does not include any presentations given in the UWW Biology Colloquia or any UWW Research Symposia.
S. Coons 2010. Neural Regions Associated with Stress in Mallards. Poster presentation at NCUR, MT.
L. Leckwee 2009. The mallard DU display: Aggression or Appeasement? Poster presentation at the National Conference for Undergraduate Research (NCUR).
A. Stelzer 2008. Challenge, hormones and dominance in mallards. Poster presentation at the NCUR meeting in California 2008.
B. Darkow 2007. The challenge effect in mallards. Poster presentation at NCUR. Also presented at the University of Wisconsin System Symposium for Undergraduate Research and Creative Activities.
B. Darkow, R. Rugen, M. Toman 2006. Testosterone correlates with male attributes important to female choice in mallards. Poster presentation at the national meeting of the Animal Behavior Society.
S. M. Smith 2006. Clicker increases resistance to extinction but does not decrease training time of a simple operant task in domestic dogs (Canis familiaris). Oral presentation given at the Behavioral Interdisciplinary Seminar at UW-Madison.
S. M. Smith 2006. Clicker increases resistance to extinction but does not decrease training time of a simple operant task in domestic dogs (Canis familiaris). Poster presentation at the national meeting of the Animal Behavior Society. Won Honorable Mention in Undergraduate Poster Competition.
R. Rugen 2006. Dominance and testosterone in mallards. Poster presentation at NCUR, North Carolina.
M. Toman 2006. Correlates of mate choice in mallards. Poster presentation at NCUR, North Carolina.
The following is a list of lab members and their activities.
Sarah Coons lab member 2008-2010; independent study Spring 2010; recipient UWW undergraduate research grant $500; presented at NCUR and UWW Undergraduate Research Day 2010.
Lauren Leckwee – lab member Spring 2008-2009; independent study Fall 2008-Spring 2009; recipient UWW undergraduate research grant $500; presented at NCUR and UWW Undergraduate Research Day 2009.
Amy Stelzer – lab member 2006-2008; independent study 2007-8; presented at NCUR and UWW Undergraduate Research Day 2008, and University of Wisconsin System Symposium for Undergraduate Research and Creative Activity 2008.
Shay Zerfas – lab member 2005-2007; independent study 2006-2007; poster UWW Undergraduate Research Day 2007.
Shawn Smith – independent study, Fall 2005: poster BEST-TERP 2005; poster, national ABS meeting 2006 (winner, honorable mention in undergraduate poster competition); first author on resulting MS.
Brian Darkow – lab member 2005-2007; independent study 2005 – 2006; thesis student 2006 – 2007; recipient UWW undergraduate research grant $500, Spring 2005; poster, NCUR 2006; poster UWW Undergraduate Research Day 2006; poster BEST-TERP 2005; poster, national ABS meeting 2006; poster, NCUR 2007; Posters in the Rotunda 2007.
Rachel Rugen – lab member 2005-2006; thesis 2005-2006; recipient UWW undergraduate research grant $500, Spring 2005; poster BEST-TERP 2005; oral presentation, UWW Biology Colloquium (with Michelle Toman), Spring 2006; poster, NCUR 2006; poster UWW Undergraduate Research Day 2006.
Michelle Toman – lab member 2005-2006; thesis 2005-2006; recipient UWW undergraduate research grant $500, Spring 2005; poster BEST-TERP 2005; oral presentation, UWW Biology Colloquium (with Rachel Rugen) Spring 2006; poster, NCUR 2006; poster UWW Undergraduate Research Day 2006.
Greg Gehrman (in-service teacher): BEST-TERP Summer 2005 & 2006
Abby Bales (undergraduate from Mt. Mary College) BEST-TERP Summer 2006; lab member also summer 2007
Abby Adams (UWW undergraduate) Fall 2005 – 2007
Ed Schorsch (UWW undergraduate) Spring 2006 – 2007
Courtney Kipperman (UWW undergraduate) Spring 2007
Jeremey Sturgill (UWW post-undergraduate) Summer 2007
Gina Laur Summer (UWW undergraduate) 2007 – 2009
Amy Zientek (in-service teacher) Summer 2008
Kristina Shirk (UWW undergraduate) Fall 2009 – Spring 2010