Meeting Abstract

56-8  Friday, Jan. 5 11:45 – 12:00  Sick birds don’t smell: Assessing the impact of haematozoan infection on avian preen oil chemical composition GRIEVES, L.A.*; KELLY, T.R.; BERNARDS, M.A.; MACDOUGALL-SHACKLETON, E.A.; The University of Western Ontario; The University of Western Ontario; The University of Western Ontario; The University of Western Ontario lgrieves@uwo.ca http://leannegrieves.com/

Haematozoan parasites such as avian malaria infect ~ 70% of bird species worldwide. Haematozoa negatively affect host fitness by decreasing reproductive success and survival. Thus, animals should experience strong selection pressure to assess the infection status of potential mates. Indicator models of sexual selection propose that condition-dependent auditory or visual ornaments, such as birdsong and plumage, can advertise infection status. Virtually nothing is known about chemical signaling of infection status in birds, despite much evidence in mammals for odour-based parasite recognition and avoidance, and despite evidence that birds produce, and attend to, odour-producing volatile chemicals in preen oil. We hypothesized that infection by malarial parasites alters the chemical composition of avian preen oil, potentially providing receivers with a chemical cue of health status. To test this hypothesis, we experimentally exposed song sparrows (Melospiza melodia) to Plasmodium parasites. We used gas chromatography to compare the chemical composition of preen oil from individuals experiencing acute infections, individuals that were exposed to Plasmodium but resisted infection, and unexposed control individuals. Perhaps surprisingly, preen oil composition did not differ significantly between groups. Although data from a broader range of parasite strains and host species are needed before chemical signaling of avian malaria can be conclusively rejected, our findings suggest that chemical signaling of haematozoan infection status may be less effective in birds than in mammals.