Based on that information Johnson schedules the statewide breeding pair count to roughly coincide with the peak of duck breeding activity. Knowing the route as they do, the two waterfowl biologists point out wetlands they haven't recorded for years, if ever. In the central part of the state, last summer's rains had a lot to do with that. In the 21 miles between Tuttle and Steele, the waterfowl survey vehicle with its flashing yellow caution light on top stopped 93 times. Imagine yourself as a rural mail carrier on a 20-mile route, with about five mail boxes per mile, and you get a pretty good feeling for that part of the survey.
Some wetlands are large and require several stops to thoroughly explore.
Some, like a flooded ditch, can be surveyed with the naked eye, but most require binoculars or a spotting scope. All the numbers put together at the end of the survey produce an index to the number of breeding pairs and water areas. One year's data by itself doesn't mean much, but when compared to other years and long-term trends, the index is a fairly accurate indicator of the duck production potential in North Dakota. Game and Fish biologists have surveyed breeding pairs of ducks since 1948, according to Johnson. The first few years transects were flown with an airplane.