
You don’t have to be a birder to recognize a duck call. The courtship whistles, odd cackles, and persistent quacking of ducks are some of the natural world’s most familiar sounds. In 2024, the U.S. Fish and Wildlife Service estimated that the North American population of wild ducks stands at around 34 million. Mallards, the most common duck species, are reckoned to number 6.6 million. Federal wildlife specialists arrive at these figures through annual surveys of duck breeding grounds, conducted from May to June, that allow them to forecast the fall flight, or the number of ducks that will migrate that autumn. Some scholars have suggested that an average fall flight before Europeans arrived in North America could have seen as many as 400 million ducks heading south. The cackling and quacking heard on the banks of the continent’s waterways in those days must have been deafening. For the Ancestral Puebloan people living in the Four Corners region near the San Juan River some 1,500 years ago, those calls seem to have taken on special resonance.