I like watching birds, an activity I developed while growing up in a forest village in Ghana where there were many different species of birds. In the city suburb where I now live, I recently observed the behavior of some crows that interested me. Flying toward a tree that had shed most of its leaves, the crows decided to take a rest. But instead of settling on the sturdy branches, they lighted on the dry and weak limbs that quickly gave way. They flapped their way out of danger—only to repeat the useless effort. Apparently their bird-sense didn’t tell them…