| Autor: |
Gulson-Castillo ER; Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109.; Museum of Zoology, University of Michigan, Ann Arbor, MI 48109., Van Doren BM; Cornell Lab of Ornithology, Cornell University, Ithaca, NY 14850., Bui MX; Department of Physics, University of Texas, Arlington, TX 76019., Horton KG; Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, CO 80523., Li J; Department of Statistics, University of Michigan, Ann Arbor, MI 48109., Moldwin MB; Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI 48109., Shedden K; Department of Statistics, University of Michigan, Ann Arbor, MI 48109., Welling DT; Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI 48109., Winger BM; Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109.; Museum of Zoology, University of Michigan, Ann Arbor, MI 48109. |
| Abstrakt: |
Space weather, including solar storms, can impact Earth by disturbing the geomagnetic field. Despite the known dependence of birds and other animals on geomagnetic cues for successful seasonal migrations, the potential effects of space weather on organisms that use Earth's magnetic field for navigation have received little study. We tested whether space weather geomagnetic disturbances are associated with disruptions to bird migration at a macroecological scale. We leveraged long-term radar data to characterize the nightly migration dynamics of the nocturnally migrating North American avifauna over 22 y. We then used concurrent magnetometer data to develop a local magnetic disturbance index associated with each radar station (ΔBmax), facilitating spatiotemporally explicit analyses of the relationship between migration and geomagnetic disturbance. After controlling for effects of atmospheric weather and spatiotemporal patterns, we found a 9 to 17% decrease in migration intensity in both spring and fall during severe space weather events. During fall migration, we also found evidence for decreases in effort flying against the wind, which may represent a depression of active navigation such that birds drift more with the wind during geomagnetic disturbances. Effort flying against the wind in the fall was most reduced under both overcast conditions and high geomagnetic disturbance, suggesting that a combination of obscured celestial cues and magnetic disturbance may disrupt navigation. Collectively, our results provide evidence for community-wide avifaunal responses to geomagnetic disturbances driven by space weather during nocturnal migration. |
