Orientation and migration are behaviors that exploit a variety of sensory cues from the environment, many of which still are very poorly understood. The discovery that the electroreceptive systems of sharks may allow the swimming fish to detect aspects of magnetic fields has opened a controversial area for geomagnetic behavior. There are field data that suggest hammerhead sharks may use local geomagnetic variation of the seafloor for cues in homing behavior after extensive foraging trips. This project uses a laboratory setting to train juvenile sharks to orient to an artificial magnetic ridge that can be changed in its topography. A related field study will test whether sharks relocated during their return homing trips will follow a predicted path given the local magnetic environment. These results will have an impact in the controversy about geomagnetic behavior, and be important for sensory neuroscience. It also may have practical application in the location and capture of important commercial species of fish.
