For nearly half a century the pintail has steadily declined, a descent that has been largely ignored by waterfowl management, waterfowl conservation organizations and most hunters. North American breeding-grounds surveys in 1956 found a record 10.4 million pintails, compared to a record low 1.8 million in 2002 – a decline of 83 percent.

In 1997 the U.S. Fish and Wildlife Service initiated a harvest strategy designed to bring about the species’ recovery. But this strategy provides little comfort for waterfowlers concerned about the future of the species. The 1997 breeding-ground survey found 3.6 million pintails. Five years later the population had dropped to 1.8 million.

These alarming statistics raise the question: Can the pintail’s decline be reversed? Can it be restored to its former abundance?

The data suggests the answer is “yes.”

One look at the following graph reveals the sad fate of the species over the past five decades.

Figure 1. The North American pintail breeding population has declined 83 percent from its 1956 peak of 10.4 million. Only 1.8 million pintails were counted in the 2002 spring survey. Source: USFWS.

To determine if recovery is possible, we first must develop a “population model” – the biological equivalent of an accountant’s profit and loss statement. Ours is similar to the U.S. Fish and Wildlife Service model. We will use a variety of USFWS data and begin in 1974 – the first year the service counted prairie potholes in both Canada and the United States.

Our population equation goes like this: We begin with the spring breeding population, subtracting 30 percent for summer mortality (from banding data). This gives us the number of adult summer survivors. We multiply this total by the age-ratio (adjusted for juvenile gunning vulnerability) to determine the number of fledged young. The fall flight then equals the sum of surviving adults and fledged young.

From the fall flight total we subtract the harvest (adjusted for a 20 percent crippling loss) and then deduct 7 percent for over-winter mortality. The result is the predicted breeding population for the following spring.

We then compare the predicted population against the surveyed population to determine the accuracy of our prediction. The predictive accuracy will determine whether it is worthwhile to continue.

Figure 2. A comparison of our calculated breeding pintail populations (shown in brown) with the official surveyed totals (shown in black) reveals a very strong correlation. This confirms the reliability of our population equation.

As you can see in the above graph, our calculated breeding population closely tracks the surveyed estimates. (Correlation analysis provides an “r” value of .77.) This suggests it should be possible to manage the population.

In 1997, the U.S. Fish and Wildlife Service initiated a program to increase the pintail breeding population by six percent a year. It sought to achieve this by cutting the daily bag limit and reducing the kill. In recent years the limit has been one daily.

The data suggests that the gun accounts for approximately 37 percent the pintail’s annual mortality. The service hoped this would increase fall-winter survival and allow more pintails to return north to breed.

This effort has failed. Pintails continue to decline. The breeding population fell from 3.6 million on 1997 to 1.8 million in 2002.

The service noted recently that it had consistently underestimated the pintail kill from 1997 to 2001 particularly in the Central and Mississippi Flyways. This was partly due to adaptive harvest, the regulatory protocol that increased the season length from 60 to 107 days, depending upon the flyway, compared to a maximum of 50 to 93 days previously.

This prompted the service last autumn the service to create a “season within a season” for the pintail that cut the number of shooting days in half. What effect this will have on the kill remains to be seen. Harvest data will not become available until this summer.

But the numbers should raise concern, as you can see in the following table. It compares the 2001-02 kill with the maximum number of pintails I calculated (based on my population model) that could be killed during the past season to allow for a six percent population increase, assuming the prairies remain dry. It reflects the management goal of distributing the kill according to historic harvest percentages – Pacific Flyway, 55%; Central and Mississippi Flyways, 20% each, and Atlantic Flyway, 5%.

A glance at the above tables suggests halving the season length will fail to achieve the desired results, the lone exception being the Pacific Flyway. Further restrictions probably will be necessary in the three eastern flyways.

What is certain is that management has failed horribly in its responsibility to manage the species. The pintail has been below its North American Plan population goal of 5.6 million since 1975. As we have shown, there is plenty of unoccupied nesting habitat on the northern prairies. Age-ratio data suggests the number of fledged juveniles has gradually increased over the past quarter-century, thus higher predation rates cannot account for the losses.

Whether the U.S. Fish and Wildlife Service and the flyway councils have the resolve to further curtail gunning for a sufficient length of time to allow our pintail flocks to rebuild remains to be seen.