Thursday, August 5, 2010

PS 73-75: The interaction of forage preference and predation risk in seasonally-varying populations of small mammals

Ryan Rebozo, Rutgers University, New Brunswick, NJ and Alicia Shenko, Rutgers University.

Background/Question/Methods

The dynamic between predator and prey relationships is an important component of understanding whole-ecosystem function. Consequently, it is also important to understand what factors drive seasonal habitat shifts, including the abandonment of one habitat in favor of another during specific times of the year. Based on previous surveys, meadow voles (Microtus pennsylvanicus) in post-agricultural cranberry bogs are replaced by white-footed mice (Peromyscus leucopus) that typically inhabit the surrounding forest. This study aims to test the predator avoidance strategies of both species to better understand forage strategies, and the cost/benefit balance between leaving the seclusion of the forest to forage in the bogs. Forage preference is being tested seasonally with treatments of predator urine and simulated avian predation risk. Forage preference is determined by the amount of seed consumed from each treatment, and individual activity is monitored by movement on track plates.

Results/Conclusions

Our preliminary results show differences between meadow vole and white-footed mouse foraging preference, and the seasonal habitat differences between the species contributes to these differences. Results vary between open cranberry bog habitat and adjacent upland forest habitat for white-footed mice which may contribute to seasonal shifts seen with this species.