Peter Thalau

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Migratory birds are known to use the geomagnetic field as a source of compass information. There are two competing hypotheses for the primary process underlying the avian magnetic compass, one involving magnetite, the other a magnetically sensitive chemical reaction. Here we show that oscillating magnetic fields disrupt the magnetic orientation behaviour of(More)
Animals make use of the Earth’s magnetic field for navigation and regulation of vegetative functions; however, the anatomical and physiological basis for the magnetic sense has not been elucidated yet. Our recent results from histology and X-ray analyses support the hypothesis that delicate iron-containing structures in the skin of the upper beak of homing(More)
The avian magnetic compass has been well characterized in behavioral tests: it is an "inclination compass" based on the inclination of the field lines rather than on the polarity, and its operation requires short-wavelength light. The "radical pair" model suggests that these properties reflect the use of specialized photopigments in the primary process of(More)
The radical pair model of magnetoreception predicts that magnetic compass orientation can be disrupted by high frequency magnetic fields in the Megahertz range. European robins, Erithacus rubecula, were tested under monochromatic 565 nm green light in 1.315 MHz fields of 0.48 μT during spring and autumn migration, with 1.315 MHz being the frequency that(More)
This paper reviews the directional orientation of birds with the help of the geomagnetic field under various light conditions. Two fundamentally different types of response can be distinguished. (i) Compass orientation controlled by the inclination compass that allows birds to locate courses of different origin. This is restricted to a narrow functional(More)
The magnetic field sensors enabling birds to extract orientational information from the Earth's magnetic field have remained enigmatic. Our previously published results from homing pigeons have made us suggest that the iron containing sensory dendrites in the inner dermal lining of the upper beak are a candidate structure for such an avian magnetometer(More)
Magnetic compass orientation of migratory birds is known to be light dependent, and radical-pair processes have been identified as the underlying mechanism. Here we report for the first time results of tests with European robins, Erithacus rubecula, in total darkness and, as a control, under 565 nm green light. Under green light, the robins oriented in(More)
Recently, oscillating magnetic fields in the MHz-range were introduced as a useful diagnostic tool to identify the mechanism underlying magnetoreception. The effect of very weak high-frequency fields on the orientation of migratory birds indicates that the avian magnetic compass is based on a radical pair mechanism. To analyse the nature of the magnetic(More)
Zebra finches can be trained to use the geomagnetic field as a directional cue for short distance orientation. The physical mechanisms underlying the primary processes of magnetoreception are, however, largely unknown. Two hypotheses of how birds perceive magnetic information are mainly discussed, one dealing with modulation of radical pair processes in(More)
By directional training, young domestic chickens have been shown to use a magnetic compass; the same method has now been used to analyse the functional characteristics and the physical principles underlying the chickens' magnetic compass. Tests in magnetic fields with different intensities revealed a functional window around the intensity of the local(More)