FB Biowissenschaften, J.W.Goethe-Universität Frankfurt, Siesmayerstrasse 70, D-60054 Frankfurt am Main, Germany.
J R Soc Interface. 2010 Apr 6;7 Suppl 2(Suppl 2):S163-77. doi: 10.1098/rsif.2009.0367.focus. Epub 2009 Oct 28.
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 window around the total intensity of the local geomagnetic field and requires light from the short-wavelength part of the spectrum. The compass is based on radical-pair processes in the right eye; magnetite-based receptors in the beak are not involved. Compass orientation is observed under 'white' and low-level monochromatic light from ultraviolet (UV) to about 565 nm green light. (ii) 'Fixed direction' responses occur under artificial light conditions such as more intense monochromatic light, when 590 nm yellow light is added to short-wavelength light, and in total darkness. The manifestation of these responses depends on the ambient light regime and is 'fixed' in the sense of not showing the normal change between spring and autumn; their biological significance is unclear. In contrast to compass orientation, fixed-direction responses are polar magnetic responses and occur within a wide range of magnetic intensities. They are disrupted by local anaesthesia of the upper beak, which indicates that the respective magnetic information is mediated by iron-based receptors located there. The influence of light conditions on the two types of response suggests complex interactions between magnetoreceptors in the right eye, those in the upper beak and the visual system.
本文综述了鸟类在各种光照条件下借助地磁场进行定向的研究。可区分出两种基本不同的反应类型。（i）由倾斜罗盘控制的罗盘定向，使鸟类能够定位不同起源的航线。这种定向受限于局部地磁场总强度附近的狭窄功能窗口，并且需要来自短波长光谱部分的光。罗盘定向基于右眼中的自由基对过程；喙中的磁铁矿受体不参与其中。在“白光”和从紫外线（UV）到约 565nm 绿光的低水平单色光下观察到罗盘定向。（ii）在人工光照条件下会出现“固定方向”反应，例如更强烈的单色光，当在短波长光中添加 590nm 黄色光，以及在完全黑暗中。这些反应的表现取决于环境光照条件，并在“固定”的意义上不显示春/秋之间的正常变化；它们的生物学意义尚不清楚。与罗盘定向相反，固定方向反应是极磁场反应，并且在广泛的磁场强度范围内发生。它们会被上喙的局部麻醉所破坏，这表明各自的磁信息是由位于那里的基于铁的受体介导的。光照条件对两种反应的影响表明，右眼中的磁受体、上喙中的磁受体和视觉系统之间存在复杂的相互作用。
