Document Type



Doctor of Philosophy



Date of Defense


Graduate Advisor

Robert E. Ricklefs, Ph.D.


Parker, Patricia

Schechter, Lisa

Klasing, Kirk


Mothers can alter offspring phenotypes through a variety of indirect effects, including the deposition of nutrients, hormones, and defense proteins in to the egg. Defense proteins, and antibodies in particular, may be tremendously important for neonatal defense against pathogens and the direction of resources into growth rather than immune responsiveness. Moreover, maternally derived immunoglobulins have been proposed to have an imprinting effect on the development of humoral immunity. In my dissertation, I explored a variety of ecological, life history, and developmental factors that could contribute to the evolution of yolk antibody allocation in a variety of avian species. In the first chapter, I measured yolk antibodies in the eggs of 23 species of small Neotropical birds from lowland Panama, and using phylogenetic regression and model selection compared among several hypotheses for life history effects on yolk antibody levels. In the second chapter, I investigate whether yolk antibodies have lasting effects on the immune response in a laboratory system of Japanese quail (Coturnix japonica). In the third chapter, I evaluate ecological factors affecting yolk antibody allocation in free-living clay-colored robins (Turdus grayi), and test whether the same patterns appear in neonatal plasma levels of maternally derived antibodies. In the final chapter, I investigate ecological variables and maternal effects on growth and immune development of clay-colored robins. Overall, I have developed several new techniques for the study of maternal effects on immunity in oviparous vertebrates, and found some evidence for developmental costs of yolk antibodies, and ecological factors influencing both the deposition and consequences of yolk antibodies.

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