Ecoimmunology provides an evolutionary perspective on immunity through the examination of the costs and benefits of investment in the immune system. In this chapter, we review key research areas, techniques and future directions in ecoimmunology, particularly as these pertain to free-living birds. Assays to assess immune function in the field vary depending on the defenses and parasites of interest as well as the ability to repeatedly sample free-living individuals. Several new field assays seek to measure innate immune responses. These include the acute-phase response, which integrates physiological and behavioral changes following infection. Recent work on the major histocompatibility complex (MHC) in an ecological context has found that MHC diversity correlates with disease dynamics in several free-living bird species. Development of the immune system in free-living birds is still understudied, especially in altricial species that develop slowly in the nest. Maternal antibody transmission remains a critical area of study, as it can provide significant pathogen resistance benefits but may carry significant costs to offspring immune ontogeny. Lastly, we discuss the important role of immune system costs, both in resources and immunopathology, in driving life history trade-offs and variation in sexually selected signals. © 2014 Elsevier Ltd All rights reserved.

Publication Title

Avian Immunology: Second Edition