How do hatching patterns impact nestling development?

Variation in nestling growth and survival is often influenced by hatching order, with first-hatched offspring having an advantage over later-hatched younger siblings. This effect of hatching order is especially evident in asynchronously hatched broods and can lead to sex-specific differences in the size and condition of nestlings. Females appear to allocate the sex of their offspring across the laying order to capitalize on these differences.

I was interested in the mechanism behind these sex-specific differences, specifically the role of the primary metabolic hormone in birds, corticosterone. This work was done for my Master’s thesis in collaboration with the Avian Ecology Lab at Illinois State University.