Factors influencing personality in Prothonotary Warbler nestlings?

Animal personality is defined as consistent expressions of an individual’s behavior when exposed to stressful conditions. Avian nestling personality traits can be determined through simple stress handling tests that measure breath rate and docility. Individuals with lower measures tend to be more bold and aggressive adults, traits that are correlated with increased fitness. Other developmental factors that correlate with increased fitness include egg size, parental provisioning rates, and body condition. The objective of this project was to determine if there is a relationship between handling stress and: egg size and parental provisioning in the migratory songbird, Prothonotary warbler (PROW). This research focused on a long-term study of a prothonotary warbler population nesting in boxes along the Lower James River. Detailed morphometric data were collected for the eggs and nestlings throughout the breeding season with regular nest checks. Nestlings were weighed and banded when they were 5-6 days old. Just prior to banding, simple docility and breathing rate stress tests were conducted. Video recordings of parental provisioning were completed and used to determine the feeding rate of each nest. No relationship was found between egg mass and the breath rate or docility stress measures. There was also no relationship between rate of provisioning and stress measures. However, there was a relationship between nestling body condition (nestling mass adjusted for age) and breath rate. It is known that larger nestlings have higher survival probabilities, and our results suggest that this relationship may not only be the result of higher body condition, but also of underlying personality differences.https://scholarscompass.vcu.edu/uresposters/1055/thumbnail.jp