Meeting Abstract

P3-116   -   The pre-fledge edge: Investigating the effects of natural variation in ectoparasite load in European starling nestlings Lusk, EP*; Price, NA; Casto, JM; Illinois State University ; Illinois State University ; Illinois State University elusk@ilstu.edu

Ectoparasitism in nestling birds can have long-lasting effects on their growth and development by inducing trade-offs. These trade-offs have been detected as decreases in measures of physical development, hematocrit and hemoglobin production, and bacteria killing ability, and increases in blood glucose, interleukin-6, and corticosterone levels. Previous research in our lab has focused on the effects of experimental manipulation of ectoparasite load to study trade-offs but has typically relied on the addition or reduction of the blood-feeding Northern fowl mite (Ornithonyssus sylviarum) and has yet to directly examine unmanipulated levels of ectoparasitism. Surveying unmanipulated mite loads in nestling birds may give us a clearer picture of the prevalence and severity of ectoparasitism and its associated trade-offs. In this study, we examined natural Northern fowl mite burdens and their relationship with the growth and development of European starling (Sturnus vulgaris) nestlings. Nests were scouted for egg laying across four different nest box colonies over 3 months, and once nestlings hatched, they were followed throughout their early development. At 10 and 20 days of age, nestlings were examined for ectoparasites, assessed for physical growth, and blood was collected to determine parameters of hematological development and corticosterone levels. On day 20, one day prior to when starlings typically leave the nest, the nestlings were sexed and their brains were collected and, 24 hours later, nests were sampled for Northern fowl mite abundance. We are currently assessing nestling structural growth as well as hematocrit, hemoglobin, and corticosterone levels. This combined with ectoparasite loads (which awaits final quantification), nestling sex, nest location, and brood data will better inform us on the effects of natural levels of ectoparasitism.