NSF Award Abstract - #0216947

AWSFL008-DS3

C-RUI Shifts in Wolf Spider Reproductive Behavior under Predation Risk

Abstract

Shifts In Wolf Spider Reproductive Behavior Under Predation Risk Ann L. Rypstra, Miami University, Hamilton Campus

At every moment, animals must weigh trade-offs and make decisions about how to allocate time and energy into foraging and reproduction while trying to minimize exposure to risks such as predation. The wolf spider, Pardosa milvina, displays effective anti-predator behavior in the presence of information about one of its major predators: the co-occurring wolf spider, Hogna helluo. The anti-predator behavior is mediated through cues (putatively silk draglines and feces) that the predator deposits as it occupies an area. Using these cues as a surrogate for predation risk, the specific costs (predation or reduced reproductive success) can be experimentally decoupled from the benefits (survival and increased reproductive success). Through manipulation of the presence or absence of H. helluo cues (perceived predation risk) with or without a living H. helluo (actual predation risk), the behavioral trade-offs and relative risk of predation can be quantified for every stage in the reproductive process. In each stage one can quantify: (1) the susceptibility of the animals to predation, (2) the behavioral changes made in response to a perceived threat of predation, (3) the degree to which those behavioral changes provide some protection from predation, and (4) the impact of altering reproductive behaviors in response to predation risk on reproductive success and fitness (survival, egg production, and phenology). Experiments will be conducted in the laboratory and in the field at Miami University's Ecology Research Center. The intellectual merit of this study lies in the fact that it will advance the understanding of predator-prey interactions. In addition, it will lead to a clearer understanding of how natural selection through predation interacts with sexual selection in shaping mating strategies at each stage of the mating process. This study will also provide a deeper understanding of the factors that allow the coexistence of two important predatory arthropods inhabiting agroecosystems. This information will lead to an understanding of the mechanisms that maintain biological diversity and will have important implications for biological control in agricultural systems. The broader impacts resulting from the proposed research lie in the development of a collaborative research community including PhDs and undergraduates from two very different institutions: a two-year open admission campus of a large state assisted university (Miami - Hamilton) and a small private liberal arts college (Susquehanna). Recruiting efforts will target non-traditional students, students from local Appalachian populations, as well as traditional minority groups. This program will unite undergraduate researchers from the two institutions behind a common research goal and, in so doing, expose them both to the culture of a different educational environment. The research program consists of a number of technically straightforward experiments that can easily be undertaken by individuals or teams of undergraduates as independent projects. The beauty of such a research program is that undergraduates can take ownership of significant portions of the project and execute them to publication. When these various projects are considered together, a comprehensive understanding of the reproduction behavior of an economically important predator will be revealed. This research program will help build the research program of a new Assistant Professor (Persons), rejuvenate the research program of a senior faculty member (Rypstra) and help a recent Ph.D. (Postdoctoral Associate) learn how to develop a research program at an undergraduate institution. Undergraduates will explore the literature, write research proposals and papers, and present their findings to their peers and to professionals at regional and national meetings.