Avian olfactory displays: a hypothesis for the function of bill-wiping in a social context
- 392 Downloads
Bill-wiping, or the scraping by a bird of its bill along a substrate, has been observed in social contexts and cited as an irrelevant displacement activity. However, several behaviors once categorized as displacement behaviors have since been shown to serve adaptive functions. Here, we hypothesize that bill-wiping may function in social interactions by releasing odors from the waxy residue of preen oil on the bill. We assessed behavioral context associated with bill-wiping by comparing the frequency of bill-wiping by free-living male songbirds when presented with a caged male or female conspecific paired with playback; males bill-wiped significantly more often in response in a courtship context and in a mate-guarding context than in a territorial context. Bill-wiping frequency correlated with courtship behaviors, such as tail spreading and singing short-range songs, but not with aggressive behaviors. We also noted attributes of individuals that engaged in bill-wiping during courtship and found that younger, smaller males performed this behavior more frequently than older, larger males. Finally, we conducted a captive Y-maze experiment to test whether dried preen oil residue would be more detectable if it were manipulated (scratched to potentially release odor) or unmanipulated. Preliminary evidence suggests that males could be more responsive to manipulated preen oil, though stronger tests are needed. Taken together, our results suggest a functional hypothesis: bill-wiping during courtship may be an olfactory display that releases odor that may be detected by potential mates and rivals. We conclude by suggesting ways in which future work can test the olfactory display hypothesis.
KeywordsChemical communication Songbirds Preen oil Courtship
We are grateful to Ellen Ketterson for discussion and helpful comments on this manuscript. We also thank Elizabeth Schultz, Stephen Ferguson, Rebecca Koch, and Abby Kimmitt for their assistance in the field. This work was supported by the National Science Foundation (DGR was supported by NSF graduate research fellowship and DDIG IOS-1011145; DJW was supported by Cooperative Agreement DBI-0939454; work was also supported by IOS-0820055 with an REU supplement to Ellen D. Ketterson). We thank Grand Teton National Park, University of Wyoming-National Park Service Research Station, and Mountain Lake Biological Station, University of Virginia.
All work was conducted in compliance with the Bloomington Institutional Animal Care and Use Committee guidelines (BIACUC protocol 09–037 in 2011, protocol 12–050 in 2013) and with permission from the US Department of Fish and Wildlife, the Virginia Department of Game and Inland Fisheries, the Wyoming Game and Fish Department, the US Department of the Interior National Park Service, and the US Forest Service.
- Clark GA (1970) Avian bill-wiping. Wilson Bull 82:279–288Google Scholar
- Cohen J (1988) Statistical power analysis for the behavioral sciences, 2nd edn. Erlbaum, HillsdaleGoogle Scholar
- Ketterson ED, Parker PG, Raouf SA, Nolan V Jr, Ziegenfus C, Chandler CR (1997) The relative impact of extra-pair fertilizations on variation in male and female reproductive success in dark-eyed juncos (Junco hyemalis). Ornithol Monogr 1997:81–101Google Scholar
- Maxwell GR, Putnam LS (1968) The maintenance behavior of the black-crowned night heron. Wilson Bull 80:467–478Google Scholar
- Nolan V Jr, Ketterson ED, Cristol DA, Rogers CM, Clotfelter ED, Titus R, Schoech SJ, Snajdr E (2002) Dark-eyed Junco (Junco hyemalis), vol 716. The Birds of North America, Inc., PhiladelphiaGoogle Scholar
- Pyle P, Howell SNG, Yunick RP, DeSante DF (2001) Identification guide to North American passerines. Slate Creek Press, BolinasGoogle Scholar
- Reichard DG, Rice RJ, Schultz EM, Schrock SE (2013) Low-amplitude songs produced by male dark-eyed juncos (Junco hyemalis) differ when sung during intra- and inter-sexual interactions. Behaviour 150:1183–1202Google Scholar