Nestling development is impacted by nutrition, parasites, and parental care. The objective of our study was to determine if nestling growth influences hematocrit ratio. From February through June of 2018, we collected physiological and morphological data from Eastern Bluebirds (Sialia sialis) and Carolina Chickadees (Poecile carolinensis) in the surrounding area of the campus of Islands High School, Chatham County, GA. We discovered that as age increases, hematocrit significantly increases as well. Also, morphological measurements and hematocrit levels are related.