The news from the North American nesting grounds is bleak. Declining numbers of breeding ducks, coupled with low numbers of potholes and inclement springtime weather, will result in a wispy fall flight.

Our 2004 fall-flight forecast calls for the number of ducks winging southward this autumn to decline 28 per cent from last year. The flight will be 30 percent below the most recent 10-year average (1904-2003). It will be 46 percent smaller than in 1997, the year that posted the largest fall flight of the past decade.

This tells us limit kills will be the exception, not the rule, and that we should reduce our expectations each day we go afield to avoid psychological disappointment.

To understand our predicament we begin by looking at pothole counts, beginning in 1994, the first year water returned to the prairies after a long drought.

Table 1. Biologists counted 3.9 million potholes across the North American breeding grounds in the spring of 2004. This total is 31 percent less than the previous year and 48 percent lower than the 1997 peak. Source: USFWS

As you can see, this year’s 3.9 million potholes total marks the second lowest total since 1994. Less than four million potholes signifies drought conditions.

Potholes, however, represent only part of the breeding equation. The second key factor involves numbers of nesting ducks. The following graph shows “total ducks,” tallies of breeding populations for eight of the 10 major species counted in the nesting-ground survey. (Only canvasbacks, redheads and incidentals are excluded.)

Table 2. This year’s “total duck” breeding population was the second lowest since 1994, totaling 27.4 million birds. This represents a 12 percent drop from 2003. Source: USFWS.

As the above graph illustrates, the “total duck” breeding population this spring declined to 27.4 million, a 12 percent drop from last year and a 28 percent decline from the 1999 peak.

The drought conditions on the prairies caused many early nesting mallards and pintails to over-fly the prairies to spend the summer in the north country. From 2003-04 mallard numbers on the prairies dropped 12 percent, while pintails decreased 32 percent. The number of mallards in the far north increased 38 percent. Pintails increased by 10 percent.

Importantly, both the prairies and the “north” geographical areas encountered inclement weather. On the prairies “snow and cold during May probably adversely affected early nesters and young broods,” the U.S. Fish and Wildlife Service said. “Birds that over-flew the prairies due to poor conditions encountered winter-like conditions in the bush, and nesting success may have been curtailed. This is especially true for mallards and pintails.”

Only Alaska escaped the ravages of spring storms.

What about later nesting species? They arrived on the breeding grounds following rains that occurred after the May surveys. Ducks Unlimited suggested “moisture conditions improved markedly since the surveys were conducted.” The state of Illinois declared that “late-nesting ducks and re-nesting ducks should do well.”

These optimistic comments contrasted sharply with a U.S. Fish and Wildlife Service official breeding-ground summary. “Many prairie areas received abundant water after May surveys, but it likely did not alleviate dry conditions, because this precipitation soaked into the ground,” the service said. “Overall production from the prairies was only poor to fair this year.”

Thus, three strikes – drought conditions, declining numbers of breeding ducks and inclement weather that reduced nest success and brood survival – limited juvenile production to a minimum.

Our fall-flight calculation, based on a somewhat complex equation involving numbers of breeding ducks, pothole counts, adult summer mortality and juvenile gunning vulnerability, suggests a 28 percent decline in the number of ducks that will wing southward this autumn.

Table 3. This year’s fall-flight index of 38.4 million represents a 28 percent decline from 2003 and a 46 percent drop from the 1997 peak.

As you can see, this year’s fall flight will be the smallest since 1994, the year water returned to the prairies following a long-term drought. It will be 46 percent smaller than the 1997 peak flight.

Importantly, our index figure of 38.4 million is not an estimate of the number of ducks we expect to wing southward. It represents a relative figure allowing us to compare this year with prior years. It includes population data for mallards, pintails, widgeon, gadwall, shovelers, green-winged teal, blue-winged teal and scaup.

Some of you may ask: How accurate is our fall-flight forecast? (The details of our fall-flight equation can be found in our 2002 fall flight forecast in the archives.)

Neither the U.S. Fish and Wildlife Service nor Ducks Unlimited produces a total-duck fall-flight index. The service, however, calculates one for mallards. This year the service’s mallard fall-flight index is 9.4 million. By comparison, our 2004 mallard fall-flight index is 9.7 million. Both represent declines from the previous year.

The message is clear. Flight after flight of ducks will not weave a living tapestry across North America’s skies this autumn. Instead, the flights will gossamer. Treasure each single duck that approaches your decoys. It may provide your only shot of the day.