GRINDSTAFF, J.L.*; HASSELQUIST, D; NILSSON, J.A.; SANDELL, M.I.; STJERNMAN, M; Indiana University, Bloomington; Lund University; Lund University; Lund University; Lund University: Maternal effects of antigen challenge on offspring growth and immunity in wild birds

Maternal effects occur when offspring phenotype is a product not only of its own genotype and the environment it experiences but also of its maternal environment. Maternal antibody transmission is one example of a maternal effect with potentially profound effects on offspring phenotype and fitness. Maternal antibodies provide the primary form of disease resistance for offspring early in life, affect differentiation of the immune system, and influence offspring growth rates. In the present study, we manipulated antigen exposure in both females and nestlings of two wild bird species, blue tits (Parus caeruleus) and pied flycatchers (Ficedula hypoleuca), to assess the effects of the quantity and types of maternal antibodies on offspring growth and immunity. The implications of our results are discussed within the context of the role of the maternal environment in offspring development and the significance of environmentally based maternal effects for phenotypic expression.