Abstract
Magnetic compass orientation in birds is based on light-dependent processes, with magnetoreception being possible only under light containing blue and green wavelengths. To look for possible intensity-dependent effects we tested Australian silvereyes during autumn migration under monochromatic green light (565 nm) produced by light-emitting diodes at various light levels. At intensities of 0.0021 and 0.0075 W/m2, the birds showed normal activity and were oriented in their seasonally appropriate migratory direction. Under low light of 0.0002 W/m2 the birds were less active; scatter increased, but they still oriented in their migratory direction. Under a high light level of 0.0150 W/m2, however, the test birds showed a counterclockwise shift in direction, preferring west-northwest instead of north. This change in behavior may reflect a change in the output of the magnetoreception system, resulting from a disruption of the natural balance between the wavelengths of light.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
Author information
Authors and Affiliations
Additional information
Received: 18 June 1999 / Accepted in revised form: 20 September 1999
Rights and permissions
About this article
Cite this article
Wiltschko, W., Wiltschko, R. & Munro, U. Light-Dependent Magnetoreception in Birds: Does Directional Information Change with Light Intensity?. Naturwissenschaften 87, 36–40 (2000). https://doi.org/10.1007/s001140050006
Issue Date:
DOI: https://doi.org/10.1007/s001140050006