Moreover, the results tipped the scales in favor of another “liberal” hunting season for all four flyways.

But the findings raised new doubts about Adaptive Harvest’s predictive capability – a key decision-making factor for effective waterfowl management.

The surveys found 5.2 million potholes, nearly double the 2.7 million reported last year. The number of Canadian potholes jumped from 1.4 million in 2002 to 3.5 million this spring, a 145 percent increase. U.S. potholes totaled 1.7 million, a 30 percent increase from the previous year.

The total number of potholes is slightly above the long-term average. Thus, wetland conditions are neither bountiful nor poor.

The distribution of ducks this spring can be seen in the following graph.

Figure 1. The Canadian prairies posted an 88 percent increase this spring in numbers of breeding ducks. Declines were reported in the Dakotas and eastern Montana (-13 percent) and the North Country (-2 percent.) Source: USFWS.

The effect increasing numbers of ducks on the Canadian prairies and fewer ducks in the Dakotas will have on this year’s juvenile production and the fall flight is unknown. Many biologists today view the Dakotas as the most productive landscape. The great expanses of upland nesting cover resulting from the Conservation Reserve Program presumably increases nest success. The relatively sparse upland cover in prairie Canada is thought to make nests more vulnerable to predators, reducing juvenile productivity.

The total number of ducks increased from 31.2 million to 36.2 million, a jump of 16 percent. Moreover, biologists reported breeding populations of all species increased this spring, as you can see in the following graph.

Figure 2. All species of ducks posted breeding-population increases this spring. Shovelers and pintails posted the highest rates of increase, while mallards and scaup posted the lowest . Source: USFWS.

The rates of increase by species from 2002 to 2003 in descending order are:

Population Changes

Species Increase

1. Shoveler 56 %

2. Pintail 43 %

3. Blue-winged Teal 31 %

4. Green-winged Teal 15 %

5. Canvasback 15 %

6. Gadwall 14 %

7. Redhead 13 %

8. Widgeon 9 %

9. Scaup 6 %

10. Mallard 6 %

On a larger scale, the “total duck” count of 36.2 million is 9 percent below the 1999 peak of 39.8 million ducks. Mallards, pintails, widgeon and scaup remain below population goals.

We also can compare this year’s totals to peak numbers of ducks counted since 1994, the year water returned to the prairies following a long-term drought. A species-by-species comparison is shown in the following graph.

Figure 3. Despite an increase this spring in numbers of breeding ducks, most species remain significantly below their 1994-03 peak population.

Thus, the increased numbers of potholes, coupled with more ducks on the Canadian prairie and fewer in the Dakotas, suggests a slightly below average to average fall-flight this autumn.

Interestingly, the breeding population increases follow a hunting season of mixed success across the nation. U.S. Fish and Wildlife Service harvest data reveals last year’s “total duck” kill increased 9 percent in the Atlantic Flyway, declined 10 percent in the Mississippi Flyway, dropped 21 percent in the Central Flyway and showed no change in the Pacific Flyway.

Of greater importance is what the breeding population surveys reveal about Adaptive Harvest, which focuses on mid-continent mallards. Adaptive Harvest’s population equation predicted a 17 percent decline in mallards this spring. Thus, it not only failed to predict the general trend (an increase instead of a decrease), but missed the specific mark by 24 percent.

This strongly suggests Adaptive Harvest remains severely flawed and calls into question its continued use as a guidestar for waterfowl management.