Meeting Abstract

P2.39  Wednesday, Jan. 5  Ectoparasites, immune function, and development in European starlings EISNER-PRYOR, L.J.*; CASTO, J.M.; Illinois State University; Illinois State University ljeisne@ilstu.edu

We carried out an experimental study of the effects of nestling ectoparasite load on growth, immunity, circulating corticosterone levels, begging and parental provisioning in European starlings. We tested adaptive immunity by randomly priming half of the nestlings in the study with PHA or saline on day 5 followed by a wing web injection of PHA on day 16. We measured the elicited primary or secondary swelling response on day 17 to assess cutaneous immunity and immune memory formation characteristic of such adaptive immunity. We tested innate immunity by performing bactericidal assays on days 5, 10 and 15 of development. Parental provisioning and nestling begging were digitally recorded on days 11 and 14. Despite treatment to reduce ectoparasites in experimental nests, control and treated nests did not differ in nestling ectoparasite burdens. We found no significant variation between day 17 primary and secondary swelling responses to PHA yet found significant increases in bacterial killing capacity with nestling age as well as significant within- and between-nest variation at all three ages. In order to explain variation both within and between nests, we analyzed the relationship between bactericidal ability and nestling mass, blood glucose, hematocrit, and parental provisioning. None of these variables showed significant correlation with bactericidal activity. Continuing analyses will measure fecal and plasma corticosteroids, nestling begging behavior and ectoparasite loads in effort to further explain the observed variation.