Title: Magnetic Orientation and Magnetoreception in Birds

Speaker: Wolfgang Wiltschko, Ph.D（Johann Wolfgang Goethe-University Frankfurt）

Time: May 17 2016 (Tue) 13:00-14:30

Venue: R1113, Wangkezhen Building, PKU

Birds use the direction of the geomagnetic field as a compass which is characterized by the following properties:

(1) it functions only in a biological around the intensity of the local magnetic field;

(2) it is an inclination compass, based on the axial course of the field lines and ignoring polarity;

(3) it is light-dependent, requiring light from the short-wavelength range of the spectrum up to 565 nm.

These unusual characteristics of the avian magnetic compass imply a very special reception mechanism. The Radical Pair Model, suggesting spin-chemical processes with cryptochrome, a flavoprotein, forming the crucial radical pairs, is in agreement with these observations. Cryptochrome 1a is found in the outer segments of the UV cones in the retina of birds and appears to provide the basis of the avian magnetic compass. Birds are also able to record the intensity of the geomagnetic field and use it as a component of the navigational map determining position. This ability seems to originate in magnetite-based receptors in the upper beak. - Birds thus have two receptors for sensing different aspects of the geomagnetic field, one for sensing magnetic directions in the eyes and one for sensing magnetic intensity in the beak.

Host: Dr. Yi Rao and Dr. Can Xie