A chimney swift is a small brown bird that weighs less than a heaping tablespoon of sugar and flies from North America to Peru every winter. In autumn the swifts form flocks to migrate southward, congregating above city roofs at dusk when as many as 5000 birds will spiral downwards into a brick chimney to roost.
Enter the US Navy.
Some far-sighted Navy scientists are trying to learn how these tiny birds can fly so close together without colliding. Why? Because the Navy has its own flock: not boats but drones.
It is a splendid vision the Navy has — unless you wonder how a sky full of drones flying close together might interact with a flock of chimney swifts.
Another splendid vision 40 years ago was a herbicide called Roundup, hailed as the farmer’s friend. Now we learn that Roundup may cause the extinction of another great migration — that of the monarch butterfly.
As darkness settles on Nash Square in Raleigh, a flock of chimney swifts descends tornado-like into a chimney on top of the Professional Building. Sometimes we may be better off appreciating the sweetness and wonder of nature without trying to grasp its secrets.
