动物依靠地磁的行为研究

Nature 464, 1140-1142 (22 April 2010) | doi:10.1038/4641140a; Published online 21 April 2010

Q&A: Animal behaviour: Magnetic-field perception

Kenneth J. Lohmann¹

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Abstract

The ability to perceive Earth's magnetic field, which at one time was dismissed as a physical impossibility, is now known to exist in diverse animals. The receptors for the magnetic sense remain elusive. But it seems that at least two underlying mechanisms exist — sometimes in the same organism.

Is there a prospect of further progress?

Yes, but new techniques and systems might be needed to pave the way. Magnetoreception research began with behavioural studies on relatively large migratory animals, but these are not necessarily the best systems for investigating transduction processes. A promising development is that three model organisms (Drosophila, zebrafish and the neurobiological model molluscTritonia) are now known to respond to magnetic stimuli. Regardless of the system used, the solution to the magnetoreception mystery will almost certainly come from a fascinating interplay of biology, chemistry and physics.

Figure 1: Animal magnetism. 

Diverse species have magnetic compasses, including (clockwise from top left) the European robin, the loggerhead sea turtle, the brown bat, the Caribbean spiny lobster and the red-spotted newt. A few, including turtles, lobsters and newts, also have magnetic maps.

Figure 2: Earth's magnetic field. 

Field lines emerge from the Southern Hemisphere, wrap around the globe, and re-enter Earth in the Northern Hemisphere. Field lines are parallel to Earth's surface at the geomagnetic equator, but become progressively steeper as an animal migrates towards the poles. Field intensity also varies predictably across Earth's surface. Thus, different geographical regions often have unique 'magnetic signatures' consisting of specific combinations of field-line inclination and intensity, as indicated by the angle and length of the arrows on the right. Animals that have magnetic maps can exploit such information when navigating to particular areas. (Reproduced from T. Alerstam Nature 421, 27–28; 2003.)

许多动物要拥有比人类灵敏的直觉，这些直觉的机理是仿生学领域研究的重要内容。人类应该加强动物种类多样性的保护，不能以人类为中心，任由动物的继续灭绝！