Meeting Abstract

P2-60    Effects of partial cross-fostering on nestling and parental behavior in Eastern bluebirds Barreto, CT*; Gutiérrez, J; Zhao, X; Tomaszewski, A; Knutie, SA; University of Connecticut; University of Connecticut; University of Connecticut; University of Connecticut; University of Connecticut cindy.barreto@uconn.edu https://cindybarreto.github.io/

Cross-fostering experiments, for which offspring are removed from their biological parents and fostering with surrogate parents, are used by animal biologists to understand how genetics vs. the environment influences traits. However, cross-fostering the offspring of wild birds can present a stressful challenge among the fostered and resident nestlings, as well as the parents. The goal of our study was to determine the effect of cross-fostering on the behavior of nestling and adult Eastern bluebirds (Sialia sialis), which is a box-nesting bird species. We partially cross-fostered nestlings or not then monitored their behavior during the day with security cameras in the nest boxes. For nestlings, we quantified the % of time spent begging; for male and female adults, we quantified the % of time spent away from the nest, brooding, feeding nestlings, perching, self-preening, cleaning the nest, sharing food with mates, and standing at the nest. Treatment did not significantly affect nestling begging behavior, although the amount of time spent begging increased with brood size. Treatment also did not significantly affect adult behavior, but males spent less time feeding the nestlings, perching, preening and cleaning the nest, and standing at the nest, compared to females. These results suggest that partial cross-fostering does not have a significant effect on bluebird behavior and could be a powerful method to understand the effects of genetics vs. environment in this system.