Walcott C, Green R P
Science. 1974 Apr 12;184(4133):180-2. doi: 10.1126/science.184.4133.180.
Homing pigeons were equipped with a pair of small coils around their heads. Birds with an induced field of 0.6 gauss and the south magnetic pole up, oriented toward home normally under both sun and overcast. Birds with the polarity reversed oriented toward home when the sun was visible but often flew away from home under overcast.
信鸽头部周围被安装了一对小线圈。感应磁场为0.6高斯且南极向上的信鸽,在晴天和阴天都能正常地朝着家的方向飞行。极性颠倒的信鸽在有太阳时能朝着家的方向飞行,但在阴天时常常会飞离家的方向。