Meeting Abstract
P3.98 Tuesday, Jan. 6 Effects of an experimental immune enhancement, rather than an immune challenge, in a wild bird. MATSON, K.D.; CARLTON, E.D.*; HOWARD, J.L.; HUDAK, C.A.; LYNN, S.E.; MAUCK, R.A.; University of Groningen; Kenyon College; Kenyon College; The College of Wooster; The College of Wooster; Kenyon College k.d.matson@rug.nl
Experimental manipulations of the immune systems of wild birds most commonly take the shape of immune challenges. These challenges are intended to induce immune responses and to force tradeoffs among limited resources (e.g. energy). Instead of challenging birds, however, we endeavored to enhance immune function in nestling Eastern bluebirds (Sialia sialis). Immune enhancement was attempted by orally supplementing young birds with a lysozyme solution throughout the nestling period. Lysozyme, a natural antibacterial protein, functions by hydrolyzing cell-wall peptidoglycan, making Gram-positive bacteria particularly susceptible to its effects. This protein, produced by many animals, has been identified in avian blood and egg albumin. Furthermore, lysozyme concentrations are known to vary among individuals (in adults, nestlings, and eggs). We hypothesized that by providing nestlings with extra lysozyme we could increase this line of immunological defense without increasing the costs associated with its production. Furthermore, we hypothesized that the relative importance of lysozyme to nestling bluebird physiology will be reflected in concomitant effects on chick immune function, growth and development, and parental care. We collected and analyzed plasma samples to establish the degree to which lysozyme treatment impacts indices of immune function, we recorded body and feather measurements to determine the effects of treatment on nestling growth and development, and we quantified feeding rates to identify any compensatory adjustments in parental behavior in response to nestling condition. Preliminary results suggest immune enhancement affects some aspects of nestling physiology, while seemingly not others.
