Meeting Abstract

19.5  Tuesday, Jan. 4  Fitness consequences of a parasite specific immune response in Darwin’s finches KOOP, Jennifer AH*; KNUTIE, Sarah A; OWEN, Jeb P; CLAYTON, Dale H; Univ. of Utah; Univ. of Utah; Washington State Univ.; Univ. of Utah jennifer.koop@utah.edu

The immune system has evolved as a defense mechanism for hosts against their parasites and pathogens. However, mounting an immune response can incur an energetic cost to the host. Ecoimmunology as a field aims to evaluate this energetic tradeoff between host immune response and host fitness. A recently introduced parasitic fly threatens the birds of the Galapagos Islands, including Darwin’s finches. Philornsi downsi is a nest ectoparasite that feeds on the blood of nestling and adult finches and has been shown to significantly decrease nestling growth and fledging success. We have recently demonstrated that adult medium ground finches, Geospiza fortis, are capable of mounting P. downsi-specific antibody responses. We experimentally manipulated P. downsi abundance in nests of medium ground finches to examine variation in both adult and nestling P. downsi-specific immune responses and subsequent fitness consequences. We aim to advance the understanding of why hosts vary in their immune responses and to better understand whether engaging the immune system is an effective defense against macroparasites.