Meeting Abstract
Relatively little is known about how large marine mammals, such as whales, accomplish their impressive long-distance migrations. An underexplored sensory modality is magnetoreception: the ability to derive positional and directional information from the earth’s magnetic field. Baleen whales are a candidate group for investigating magnetoreception in mammals due to their long migrations and the unique navigational challenges they face in the featureless open ocean. In this environment, it could be advantageous to derive navigational cues from the geomagnetic field because it is relatively constant and ubiquitous. While it is difficult to perform behavioral experiments on whales, it may be possible to use live stranding data (strandings in which the whale may have made a navigational error, rather than those in which a whale died at sea and washed ashore) as a tool for investigating their navigational senses. We used gray whale (Eschrichtius robustus) stranding data from the US west coast (n=186). We found that gray whales strand more often on days with high levels of solar radio flux (RF, p<0.0001) than on random calendar days. RF is strongly correlated with solar storms – sudden releases of high-energy particles from the sun that interact with parts of the earth’s magnetosphere. One hypothesized mechanism for magnetoreception, the radical-pair mechanism, predicts that magnetoreception can be disrupted by radio-frequency radiation, and RF noise has been shown to disrupt magnetic orientation in certain species. These results indicate a magnetic sense in whales, which may be mediated by a radical-pair mechanism.
