Department of Biological Sciences, Virginia Tech, 4100 Derring Hall, Blacksburg, VA 24061-0406, USA.
Proc Biol Sci. 2010 Jan 7;277(1678):45-9. doi: 10.1098/rspb.2009.1521. Epub 2009 Oct 7.
The sensory basis of the navigational map remains one of the most important and intriguing questions in animal behaviour. In birds, odours have been hypothesized to provide the primary source of map information. Convincing tests have shown that experienced homing pigeons rely on map information obtained at sites where they are exposed to natural odours, even if subsequently released (without additional olfactory information) at a different site. These findings have been interpreted as support for the olfactory map hypothesis. Using this 'false-release-site' (FRS) approach, we compared the effects of exposure to natural odours with that of exposure to a series of artificial odours lacking spatial information. Our findings show that olfactory exposure to either natural or artificial odours at an FRS caused pigeons to rely on map information obtained at the FRS, even if subsequently released at the true-release site in the opposite direction from the home loft. Because artificial odours did not provide map information, however, the findings clearly demonstrate that olfactory exposure provides no navigational information to pigeons whatsoever; instead it activates an independent non-olfactory map system. This test decisively contradicts the olfactory map hypothesis, which predicts that olfactory cues are the primary source of navigational information used by birds.
导航图的感觉基础仍然是动物行为中最重要和最有趣的问题之一。在鸟类中，气味被假设为提供地图信息的主要来源。令人信服的测试表明，有经验的归巢鸽依赖于在它们接触自然气味的地点获得的地图信息，即使随后在不同的地点释放（没有额外的嗅觉信息）。这些发现被解释为对嗅觉地图假说的支持。使用这种“虚假释放地点”（FRS）方法，我们比较了暴露于自然气味与暴露于缺乏空间信息的一系列人工气味的效果。我们的研究结果表明，在 FRS 处暴露于自然或人工气味都会导致鸽子依赖于在 FRS 处获得的地图信息，即使随后从真正的释放地点从鸽舍的相反方向释放。然而，由于人工气味不能提供地图信息，因此这些发现清楚地表明，嗅觉暴露对鸽子没有任何导航信息；相反，它激活了一个独立的非嗅觉地图系统。该测试断然反驳了嗅觉地图假说，该假说预测嗅觉线索是鸟类使用的主要导航信息来源。
