Using Individual-based Modeling to Explore How Environmental and Anthropogenic Factors Impact Piping Plover Breeding Success

Cohen, Alexander J. M.S., Purdue University, December 2014. Using Individual-based Modeling to Explore How Environmental and Anthropogenic Factors Impact Piping Plover Breeding Success. Major Professor: Patrick A. Zollner. The Piping Plover (Charadrius melodus) is an intensively managed shorebird species which breeds in part along the Atlantic Coast. Major threats to Piping Plovers include habitat loss and degradation, predation, human disturbance, and vulnerability to the elements. Common management techniques include predator exclosures and symbolic fencing around nests to deter humans from entering nesting areas. However, Piping Plover productivity is highly variable even with management. Many siteand seasonspecific factors affect plovers and their interactions with other inhabitants of the beach environment. Variability in magnitude and patterns of human disturbance, plover behavioral tolerance of disturbance, and a variety of beach characteristics may have important impacts on plover breeding success. Accounting for each of these factors, along with their interactions, is a difficult task empirically. However, simulation modeling tools allow for creation of virtual worlds and the ability to simultaneously manipulate factors of interest. In this thesis, I apply two individual-based modeling tools to explore how plover productivity (e.g. survival, energetics, and behavior) is determined by the functioning of individual plovers, as well as their interactions with individual humans and, in the second model, individual predators. For the first model application, I employed the individual-based model SODA (Simulation of Disturbance Activities) to explore the implications of human disturbance on plovers. I created digital representations of 15 Massachusetts beaches and measured relevant spatial characteristics (e.g. beach width, configuration of symbolic fencing). I then created 20 combinations of