title: Geomagnetic imprinting predicts spatio-temporal variation in homing migration of pink and sockeye salmon.
abstract: Animals navigate using a variety of sensory cues, but how each is weighted during different phases of movement (e.g. dispersal, foraging, homing) is controversial. Here, we examine the geomagnetic and olfactory imprinting hypotheses of natal homing with datasets that recorded variation in the migratory routes of sockeye (Oncorhynchus nerka) and pink (Oncorhynchus gorbuscha) salmon returning from the Pacific Ocean to the Fraser River, British Columbia. Drift of the magnetic field (i.e. geomagnetic imprinting) uniquely accounted for 23.2% and 44.0% of the variation in migration routes for sockeye and pink salmon, respectively. Ocean circulation (i.e. olfactory imprinting) predicted 6.1% and 0.1% of the variation in sockeye and pink migration routes, respectively. Sea surface temperature (a variable influencing salmon distribution but not navigation, directly) accounted for 13.0% of the variation in sockeye migration but was unrelated to pink migration. These findings suggest that geomagnetic navigation plays an important role in long-distance homing in salmon and that consideration of navigation mechanisms can aid in the management of migratory fishes by better predicting movement patterns. Finally, given the diversity of animals that use the Earth's magnetic field for navigation, geomagnetic drift may provide a unifying explanation for spatio-temporal variation in the movement patterns of many species.
authors: Department of Fisheries and Wildlife, Oregon State University, 104 Nash Hall, Corvallis, OR 97331, USA nathan.putman@gmail.com.
authors: Nathan F
authors: NF
authors: Putman
authors: Pacific Salmon Commission, 600-1155 Robson Street, Vancouver, British Columbia, Canada V6E IB5.
authors: Erica S
authors: ES
authors: Jenkins
authors: Pacific Salmon Commission, 600-1155 Robson Street, Vancouver, British Columbia, Canada V6E IB5.
authors: Catherine G J
authors: CG
authors: Michielsens
authors: Department of Fisheries and Wildlife, Oregon State University, 104 Nash Hall, Corvallis, OR 97331, USA Oregon Hatchery Research Center, 2418 East Fall Creek Road, Alsea, OR 97324, USA.
authors: David L G
authors: DL
authors: Noakes
mesh_terms: D025041:Animal Migration / Q000502:physiology*; D000818:Animals; D001955:British Columbia; D005843:Geography; D006702:Homing Behavior / Q000502:physiology*; D007173:Imprinting, Psychological / Q000502:physiology*; D016014:Linear Models; D060328:Magnetic Phenomena; D008954:Models, Biological; D010140:Pacific Ocean; D012474:Salmon / Q000502:physiology*; D012903:Smell / Q000502:physiology; D013045:Species Specificity; D013696:Temperature; D014872:Water Movements
keywords: geomagnetic secular variation; homing; magnetic navigation; migration; movement ecology; salmon