A comparison of fecal sac removal rates of male and female Carolina Chickadees (Poecile carolinensis)

Abstract

Parent songbirds keep their nests clean by removing nestling waste in the form of fecal sacs. Removing fecal sacs is beneficial for the nestlings but energetically costly for the parents. The purpose of our research was to determine whether there was a difference in energy spent on fecal sac removal between male and female Carolina Chickadees (Poecile carolinensis). We collected data for this project at St. Anne Woods and Wetlands in Melbourne, Kentucky, where we made a total of 215 one-hour observations of 30 different nests. For each color-banded parent, we calculated both the number of fecal sac removals and the number of removals divided by the total number of nest visits per hour. Our results showed that males removed more fecal sacs per hour than females. However, this was only because they visited the nest more frequently, as the number of fecal sac removal visits per provisioning visit was the same between the sexes. This suggests that parental energy invested in fecal sac removal is closely tied to their investment in nestling provisioning visits.