Utvenko Gleb, Gorvat Polina, Grebenkova Anastasia, Pakhomov Alexander, Chernetsov Nikita
Biological Station Rybachy, Zoological Institute of the Russian Academy of Sciences, 238535 Rybachy, Kaliningrad Region, Russia.
Department of Vertebrate Zoology, Lomonosov Moscow State University, 119234 Moscow, Russia.
J Exp Biol. 2025 Feb 1;228(3). doi: 10.1242/jeb.248169. Epub 2025 Jan 30.
Every year, billions of birds migrate to optimize their foraging, shelter and breeding. They use an inclination compass, which, unlike the technical compass, distinguishes between the directions towards the magnetic equator from the magnetic pole based on magnetic inclination angles, which range from ±90 deg at the poles to 0 deg at the equator. During autumn migration, some species cross the magnetic equator, where field lines are horizontal, i.e. the inclination angle is 0 deg. At this point, the avian magnetic compass becomes ambiguous, because the birds can no longer distinguish 'to the pole' from 'to the equator'. Experiments with bobolinks and garden warblers have shown that these birds adaptively change their orientation when exposed to a horizontal magnetic field. We tested this in marsh warblers and spotted flycatchers, but they showed no such response, suggesting they may use other cues. This indicates that different species may rely on varying stimuli, and the current experimental models may not be universally applicable.
每年，数十亿只鸟类迁徙以优化它们的觅食、栖息和繁殖条件。它们使用一种倾斜罗盘，与技术罗盘不同，这种罗盘根据磁倾角区分朝向磁赤道和磁极的方向，磁倾角在两极处为±90°，在赤道处为0°。在秋季迁徙期间，一些物种会穿过磁力线呈水平状（即倾斜角为0°）的磁赤道。此时，鸟类的磁罗盘变得模糊不清，因为鸟类无法再区分“向极”和“向赤道”。对食米鸟和花园莺的实验表明，当暴露在水平磁场中时，这些鸟类会适应性地改变它们的方向。我们在沼泽莺和斑姬鹟身上测试了这一点，但它们没有表现出这样的反应，这表明它们可能使用其他线索。这表明不同物种可能依赖不同的刺激，并且当前的实验模型可能并非普遍适用。
