Ryan Stutzman will defend his master thesis, "Stopover Decisions of Migratory Shorebirds: An Assessment of Habitat Use, Food Availability, Behavior and Phenology," at 1 p.m., Thursday, Nov. 8, in room 901 at Hardin Hall. His adviser is Joseph Fontaine.
Abstract:
Habitat decisions have important implications to individual fitness as well as population dynamics and community structure. Understanding how changes to ecosystem structure and function impact species and populations of conservation concern is essential for conservation delivery to be effective. During 2010-2011, I examined how long-distance migratory shorebirds have responded to extensive, agriculturally-driven alteration to wetland habitats. I focused on a suite of ecological conditions that are expected to influence migrant fitness including habitat preference, resource availability and behavior. Additionally, because land use change is expected to act in conjunction with climate change to alter wetland habitats, I examined a number of phenologic variables and made predictions on how migrants might be affected in the future.
Migrant shorebirds were more likely to use highly-altered, agricultural wetlands and did so in greater numbers. Preference for altered habitat was unexpected because these habitats had lower resource availability but preference may be explained by the role of mud flat as an influential cue, which would increase the attractiveness of agricultural wetlands. However, behavioral analysis indicates that migrants have adapted to using novel habitats through increased foraging efficiency. Despite their apparent adaptability to changing conditions, migrant shorebirds may still be susceptible to further population decline as a result of changes in phenology brought about by climate change. Results show that timing of peak migration is correlated with the availability of food resources. Given that shorebird migrants already prefer habitat with lower resource availability, any changes to either invertebrate or migration phenology that is not congruent in both magnitude and direction to the other could have severe impacts on migrant populations.