title: Experienced migratory songbirds do not display goal-ward orientation after release following a cross-continental displacement: an automated telemetry study.
abstract: The ability to navigate implies that animals have the capability to compensate for geographical displacement and return to their initial goal or target. Although some species are capable of adjusting their direction after displacement, the environmental cues used to achieve this remain elusive. Two possible cues are geomagnetic parameters (magnetic map hypothesis) or atmospheric odour-forming gradients (olfactory map hypothesis). In this study, we examined both of these hypotheses by surgically deactivating either the magnetic or olfactory sensory systems in experienced white-throated sparrows (Zonotrichia albicollis) captured in southern Ontario, Canada, during spring migration. Treated, sham-treated, and intact birds were then displaced 2,200 km west to Saskatchewan, Canada. Tracking their initial post-displacement migration using an array of automated VHF receiving towers, we found no evidence in any of the groups for compensatory directional response towards their expected breeding grounds. Our results suggest that white-throated sparrows may fall back to a simple constant-vector orientation strategy instead of performing true navigation after they have been geographically displaced to an unfamiliar area during spring migration. Such a basic strategy may be more common than currently thought in experienced migratory birds and its occurrence could be determined by habitat preferences or range size.
authors.affiliation: Department of Integrative Biology, University of Guelph, 50 Stone Road East, N1G 2W1 Guelph, Ontario, Canada.|School of Biological Sciences, Bangor University, Deiniol Road, LL57 2UW Bangor, Gwynedd, UK.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Kishkinev
authors.affiliation: AG Neurosensorik / Animal Navigation, Institute of Biological and Environmental Sciences, University Oldenburg, D-26111 Oldenburg, Germany.
authors.forename: Dominik
authors.initials: D
authors.lastname: Heyers
authors.affiliation: Department of Integrative Biology, University of Guelph, 50 Stone Road East, N1G 2W1 Guelph, Ontario, Canada.
authors.forename: Bradley K
authors.initials: BK
authors.lastname: Woodworth
authors.affiliation: Wildlife Research Division, Environment and Climate Change Canada, National Wildlife Research Centre, 1125 Colonel By Drive, K1H 0H3, Canada, Ottawa, Ontario, Canada.
authors.forename: Greg W
authors.initials: GW
authors.lastname: Mitchell
authors.affiliation: Wildlife Research Division, Environment and Climate Change Canada, 11 Innovation Boulevard, S7N 3H5 Saskatoon, Saskatchewan, Canada.|Department of Biology, University of Western Ontario, N6A 5B7, London, Ontario, Canada.
authors.forename: Keith A
authors.initials: KA
authors.lastname: Hobson
authors.affiliation: Department of Integrative Biology, University of Guelph, 50 Stone Road East, N1G 2W1 Guelph, Ontario, Canada.
authors.forename: D Ryan
authors.initials: DR
authors.lastname: Norris
mesh_terms: D025041:Animal Migration / Q000502:physiology*; D000818:Animals; D003463:Cues; D005843:Geography; D006040:Goals; D008280:Magnetics; D009864:Ontario; D000072458:Orientation, Spatial / Q000502:physiology*; D012621:Seasons; D012903:Smell / Q000502:physiology; D020308:Songbirds / Q000502:physiology*; D013686:Telemetry / Q000379:methods*