The water area could be a wetland, river, creek, ditch or livestock dugout. Every duck observed within 220 yards of the road is recorded, whether it's sitting on a wetland or flying. Ducks are classified by species, and by their behavior characteristics. For instance, two drake mallards sitting together are listed as 2-0 under the mallard category for a particular wetland. Just because those drakes aren't with a hen, doesn't mean they aren't breeding.
Mallards are early nesters.
By the time the pair count starts in mid-May, most mallard hens are sitting on a nest. The drakes have likely already mated. Unless they are in a group or five or more, they count as part of a breeding pair. In those cases, Johnson says the hen probably lost her first nest to a predator, and has chosen a drake that had been just sitting around, as a new mate to initiate a renesting attempt. Stopping frequently and recording water areas and ducks can become a tedious chore, especially in wet years, but for a waterfowl biologist it could be termed a labor of love.