Magnetic orientation and magnetoreception in birds and other animals
Publication Type: |
Journal Article |
Year of Publication: |
2005 |
Authors: |
Wolfgang Wiltschko, Roswitha Wiltschko |
Publication/Journal: |
Journal of Comparative Physiology A |
Keywords: |
amphibians, birds, chemical compass, fish, magnetic navigation, magnetite particles, magnetoreception |
ISBN: |
0340-7594 1432-1351 |
Abstract:
Animals use the geomagnetic field in many ways: the magnetic vector provides a compass; magnetic intensity and/or inclination play a role as a component of the navigational ‘map’, and magnetic conditions of certain regions act as ‘sign posts’ or triggers, eliciting specific responses. A magnetic compass is widespread among animals, magnetic navigation is indicated e.g. in birds, marine turtles and spiny lobsters and the use of magnetic ‘sign posts’ has been described for birds and marine turtles. For magnetoreception, two hypotheses are currently discussed, one proposing a chemical compass based on a radical pair mechanism, the other postulating processes involving magnetite particles. The available evidence suggests that birds use both mechanisms, with the radical pair mechanism in the right eye providing directional information and a magnetitebased mechanism in the upper beak providing information on position as component of the ‘map’. Behavioral data from other animals indicate a lightdependent compass probably based on a radical pair mechanism in amphibians and a possibly magnetitebased mechanism in mammals. Histological and electrophysiological data suggest a magnetite-based mechanism in the nasal cavities of salmonid fish. Little is known about the parts of the brain where the respective information is processed.