Meeting Abstract

84.2  Friday, Jan. 7  The woes of parenthood: the stress of an introduced nest parasite on Darwin’s finches KNUTIE, S.A.*; KOOP, J.A.H.; FRENCH, S.S.; CLAYTON, D.H.; University of Utah, Salt Lake City; University of Utah, Salt Lake City; Utah State University, Logan; University of Utah, Salt Lake City saknutie@gmail.com

The introduction of exotic parasites to an island ecosystem can reduce native host population size and biodiversity. Philornis downsi (Diptera: Muscidae) is an invasive fly, recently introduced to the Galapagos Islands, whose larvae parasitize the nestlings and adults of many native bird species. Studies show that larvae reduce fitness of many Darwin’s finches, however, there has been no test of the impact of P. downsi on host stress physiology or behavior. Although short-term elevations in corticosterone, a stress hormone in birds, may help to enhance survival through changes in behavior, chronically elevated levels of baseline corticosterone can be detrimental to the immune system and ultimately, fitness. The impact of parasitism by P. downsi on Medium ground finch (Geospiza fortis) stress physiology and how stress relates to parental behavior and ultimately reproductive success will be discussed. Our study enforces the importance of studying not only the effects of an introduced species on avian host population dynamics, but will encourage further studies on how the invader impacts host biology.