Fachbereich Biowissenschaften, J. W. Goethe-Universität Frankfurt, Siesmayerstraße 70, D-60054 Frankfurt am Main, Germany.
J Exp Biol. 2011 Sep 15;214(Pt 18):3096-101. doi: 10.1242/jeb.059212.
The avian magnetic compass is an inclination compass that appears to be based on radical pair processes. It requires light from the short-wavelength range of the spectrum up to 565 nm green light; under longer wavelengths, birds are disoriented. When pre-exposed to longer wavelengths for 1 h, however, they show oriented behavior. This orientation is analyzed under 582 nm yellow light and 645 nm red light in the present study: while the birds in spring prefer northerly directions, they do not show southerly tendencies in autumn. Inversion of the vertical component does not have an effect whereas reversal of the horizontal component leads to a corresponding shift, indicating that a polar response to the magnetic field is involved. Oscillating magnetic fields in the MHz range do not affect the behavior but anesthesia of the upper beak causes disorientation. This indicates that the magnetic information is no longer provided by the radical pair mechanism in the eye but by the magnetite-based receptors in the skin of the beak. Exposure to long-wavelength light thus does not expand the spectral range in which the magnetic compass operates but instead causes a different mechanism to take over and control orientation.
鸟类的磁罗盘是一种倾斜罗盘，它似乎基于自由基对过程。它需要来自光谱短波长范围的光，直到 565nm 的绿光；在更长的波长下，鸟类会迷失方向。然而，当它们预先暴露在 1 小时的长波长光下时，它们会表现出定向行为。本研究在 582nm 黄光和 645nm 红光下分析了这种定向：春季鸟类更喜欢北方方向，而在秋季它们没有南方倾向。垂直分量的反转没有影响，而水平分量的反转则导致相应的位移，表明涉及到对磁场的极地反应。兆赫兹范围内的振荡磁场不会影响行为，但上喙的麻醉会导致迷失方向。这表明，磁信息不再由眼睛中的自由基对机制提供，而是由喙部皮肤中的磁铁矿受体提供。因此，长波长光的照射不会扩大磁罗盘运行的光谱范围，而是会导致另一种机制接管并控制方向。
