Within humans it is widely recognized that early differences in personality shape the development of behavior. For instance, extraverts commonly seek out interactions with unfamiliar individuals, while introverts consistently seek out interaction with fewer more familiar individuals. Thus, personality may shape an individual's behavioral development by exposing them to different social experiences from an early age. Recently there has been increasing awareness that like humans, animals also possess personality traits. The proposed research will investigate how variation in a personality trait, sociability, shapes behavioral development in Brown-headed Cowbirds (Molothrus ater). Cowbirds, like many other species, rely on social interaction in order to learn new skills and behaviors. Sociability describes an individual's tendency to seek out interaction with others. More sociable cowbirds will approach and interact with more individuals more often than less sociable cowbirds. Two studies will investigate if: 1) Variation in sociability predicts the development of adult like behavior in juvenile cowbirds, and 2) if early experience with more or less sociable adults shapes the development of juvenile personality traits. A new RFID based video system will be used in both studies to identify individuals and record their social behaviors over long periods of time. This system will allow measurement of the details of sociability and social behavior in a way that was unavailable to researchers before. Statistical time series models can be implemented to uncover how an individual's sociability reflects the development of new behaviors over the first year of life. In the second experiment, statistical time series models will be used to uncover if experience with more sociable adults can predict the emergence of adult-like behavior within a juvenile cowbirds' first year. These results will provide insights into how early personality differences shape the development of behavior by determining how individuals interact and learn from others.
Data will be stored and available at http://datadryad.org/