Researchers in Japan documented carrion crows placing walnuts in front of cars stopped at traffic lights, then letting the vehicles crack the shells before retrieving the food — behaviour recorded repeatedly over 21 months.
A road junction in Sendai, Japan, in the early 1990s. The traffic light turns red, a line of cars stops, and a crow appears on the road just in front of a front tire. He drops a nut, then flies back to the sidewalk and waits. The light turns green, a tire passes over the … Read more
