translation.en: That's not in doubt -- a German couple of ornithologists, Wolfgang and Roswitha Wiltschko, in the 1970s, confirmed that indeed, the robin does find its way by somehow sensing the Earth's magnetic field, to give it directional information -- a built-in compass.
translation.zh: 毋庸置疑——德国的鸟类学家夫妇 Wolfgang和Roswitha Wiltschko在20世纪70年代确认， 知更鸟的确通过感应地球磁场来探路， 从中获取方向信息——这是一种内置的指南针。