Effects of Captivity on Foraging Behavior and Survival in the Wild of Microtus Pennsylvanicus

Abstract

Human activity has caused wildlife populations worldwide to decline making it imperative for conservation biologists to develop captive breeding and reintroduction programs. These programs, however, have had limited success. Captivity has been shown to select for behavioral traits that are maladaptive in the wild, such as inability to recognize optimal food resources, thereby minimizing survival. I developed this study to explore the mechanisms involved with behavioral change in a systematic and hypothesis-driven framework. I captured, housed and later tested meadow voles (Microtus pennsylvanicus) in a foraging test to measure behavioral differences as a function of environment and time. Animals were housed in either a simple or complex environment for greater than or less than 1.5 months. Analysis of behavioral data from the foraging test suggests the complex environment may maintain appropriate foraging behaviors for sexes and a short time in a simple environment may maintain appropriate responses to unpredictability. All subjects along with a wild cohort were subsequently released into outdoor enclosures and survival was monitored. Analysis of mark-recapture data suggests environment and time do affect survival and recapture of individuals differently; animals housed in complex environments (for less than 1.5 months) maintained similar survival rates as wild individuals. My study suggests that captive individuals may benefit from additional complexity (for short time intervals) within the captive environment to maintain wild behaviors and increase survival upon reintroduction.