THE PRAIRIE CYCLE
Droughts, Ducks, and Man
What have we learned? What do we do?
By Scott Yaich, Ph.D.

. . . we believe it soon will be too late to save [wild-fowl] in numbers sufficient to be of any real importance for recreation in the future.

John Phillips and Frederick Lincoln, 1930,
From American Waterfowl: Their Present Situation and Outlook for the Future

Omigosh! Duck populations are how much lower than last year? How could this have happened!? Whos to blame for this? Weve got to fix this, and right now, before its too late!
Everyman, 1930s, 1960s and 1980s, from all over America

If the 2002 prairie drought continues, and if the passions displayed over the past 100 years are any indication, we may be facing d��vu all over again. As we attempt to manage ducks in reaction to the undeniable natural forces of drought, we should adopt an attitude of determination to channel our passions for waterfowl into the most beneficial actions.

To get ready for what the next dry cycle could have in store for ducks, we can benefit from a little historical review. A duck population cycle can take many years to play out. Thus, some historical perspective can provide more understanding than any of us can achieve with only our personal experiences as hunters or waterfowl managers. That perspective includes data concerning numbers of ducks, ponds, and hunters. But, it also includes the passions of those who have preceded us in sharing a love of waterfowling.

. . . [The mallard] is still found in great abundance, but according to experienced gunners is decreasing yearly in numbers.
Arthur Howell, 1911, from Birds of Arkansas

. . . the ducks are still fairly abundant.
W.J. Baerg, 1931, from Birds of Arkansas

At present the duck population is far below that of 20 years ago.
W.J. Baerg, 1951, from Birds of Arkansas

Arkansas sets record duck and mallard harvests during the 1999 season.
Arkansas Game and Fish Commission, July 2000

The first three quotes illustrate the feeling that things just keep getting worse, a sense that reappears with every duck population downturn. That may have been a reasonable generalization for the first half of the 20th century. However, the latter quote counters that the last half of the century saw some good times for ducks. In the face of ongoing habitat loss, how can this be?

In the mid-1800s, settlement first scratched the surface of the expansive landscape of prairie grasslands and potholes that fledge so many of North Americas ducks. Populations of most species were as high as anyone would ever see. But things changed quickly. With duck numbers apparently declining rapidly during the late 19th century, concern for the resource motivated actions that ushered in the modern era of conservation in the early decades of the 20th century. Although populations rose during the early years of the 1900s, 1915 brought dry conditions to the prairies. By the 1920s, populations were declining again, and with the early 1930s came the depths of the Dust Bowl. Those years may have seen the lowest duck populations in history.

The drought finally broke in 1935, and duck populations rebounded. But, dry periods continued to come and go, as they always have and always will. Generally correlating with water conditions on the prairies, duck populations were down in the late 1940s, hit record highs in the late 1950s, sank to lows in the early to mid-1960s, and experienced largely good years in the 1970s. More recently, many of us remember the very long, steady decline of the 1980s, and enjoyed the 1990s rebound to levels comparable to those of the 1950s.

Precipitation, however, is only part of the habitat equation driving duck populations. During the 20th century, man made dramatic, long-term changes to the canvas of the prairie parkland landscape on which the natural wet-dry cycles paint the habitat picture. Between 1901 and the mid-1950s, prairie Canada farmland grew from 5 million to 101 million acres. The same thing happened on the U.S. prairiesjust sooner, more quickly, and more completely. Although at a slower rate, habitat loss continued through the 20th century. Pothole basins were also affected. In the late 1800s, there were 9-10 million potholes in Canadas prairie parklands. Forty- eight percent were lost or impacted by 1930, and nearly 70 percent by 1964.

In the face of these tremendous habitat changes, some wonder how is it that ducks are not worse off than they are? After all, the late 1990s brought us total duck populations similar to the 1950s and some record harvests. We need to look at individual species to get a more complete picture. Mallards, gadwalls, and most other prairie species did indeed reach or exceed their population peaks of the 1950s. However, changes in their habitats prevented pintails and scaup from recovering to former levels. These species are going to need more focused attention in coming years.

Prairie ducks have had 10,000 years and hundreds of droughts since the last ice age to adapt to their highly dynamic habitats. To illustrate that variability, a study area in Saskatchewan that supported only one breeding pair for every three square miles in the dry spring of 1959 held breeding duck numbers 220 times higher in the wet spring of 1965. Between 1959 and 1961, 5.5 to 7 million mallards were without a suitable place to nest on the drought-stricken prairies. What happens to those millions of birds? Well, to put it simply, a primary adaptation to prairie drought is to just keep on flyin north to the western boreal forest and beyond to the arctic river deltas. So, if the birds are still alive but just farther north, why do populations go down so much? The answer is that many of the drought-displaced birds fail to breed in those northern areas. Those that do attempt to nest produce far less, on the average, than when they nest on the fertile prairies.

During wet years, the ducks land on the prairies, go forth and produce. Most species have demonstrated they can still be explosively productive when the water and grasslands are present on the prairies together. For example, the mid-continent mallard population went from 6.6 to 9.3 million between 1993 and 1995 (+42 percent), and increased further to 11.8 million (+79 percent) by 1999. However, when the prairies cannot sustain the large populations built during the boom years, populations decrease to a level sustainable by the remaining habitats. When the rains return to the prairies, the cycle begins anew.

Drought is a necessary evil (see the September/October 2002 issue of Ducks Unlimited). Without periodic drying, pothole productivity declines dramatically, and the ability of the landscape to produce ducks declines with it, even when it is wet. Drought is one aspect of nature we cant control. So, lets accept that it may be happening again and ask ourselves: What we can do to help get waterfowl through leaner times?

Many hunters came home with empty bags. Others were more fortunate. The season was disastrous enough, however, to convince the true sportsmen among the duck hunters that something was seriously amiss. Nature magazine, April 1935, from A Closed Season: Now or Forever

It can be difficult to accept that there is nothing we can do to prevent populations from declining during drought. Literature of the past century is filled with impassioned pleas for something to be done now to save waterfowl whenever duck numbers declined. These passions led to the formation of Ducks Unlimited in 1937. Unfortunately, too much of the passion generated by each 20th century drought has lacked focus. Blaming fingers were first pointed in every direction, and much energy was wasted assigning fault. Then the search would begin for the silver bullet with which to reverse the continental duck population decline.

Pretty much the same ideas have surfaced with each drought. The idea of stocking pen-raised ducks makes a regular appearance. In 1935, William Adams, director of Fish and Game of New York state, said, Lets raise a duck for every one we kill. Through decades of trying throughout the continent, stocking was repeatedly shown to be ineffective for bolstering wild duck populations. Predator control is another management practice that gets increased attention during each population downturn. It can be an effective tool to temporarily benefit production from relatively small areas, but it cannot measurably affect populations on a large scale.

The issue of hunting has always fostered the greatest debates. In 1935, one organization stated the opinion that whatever the differing beliefs . . . as to the principal causes of . . . decline, the fact remains that control of killing of waterfowl by man is the only means we have of quickly contributing to the restoration of an adequate breeding stock. Thus, the passionate urge to do something and the desire to find the quick fix seem to triangulate on hunting.

Cries for closed seasons arose during the 1930s, 1960s, and 1980s. In April 1935, Nature magazine even stated that such a course must be followed if the dwindling species are to be saved from extinction. Although the duck season has never been closed, these calls invariably energize advocates of the other end of the philosophical spectrum who believe that hunting has no impact on the following years fall flight (see the November/December 2002 issue of Ducks Unlimited). Like most things in life, reality is somewhere in between and considerably more complex. In addition, the details of these relationships vary considerably among species.

Relatively recent data help illustrate why a completely closed season would not be the quick population fix that some have believed. From 1988-1990, the season length and mallard bag limit in the two eastern flyways was 30 days and two drakes (one hen). During that period, total annual mortality of adult hens was about 40-45 percent, and about 7 percent of the adult female population was harvested. Proponents of a closed season would quickly point out that most of those hens would be alive to breed if they were not harvested. True enough, but the small proportion of hens that would have been saved by closing a season at that time (up to 7 percent) would still have faced drought-parched prairies when they flew north. Like all the other drought-displaced hens, then, they would either not have nested or may have done so with limited success. Overall, the benefit to the following fall flight would likely have been less than a 1 percent difference in population size. Would that be worth the social and habitat costs of closing the season? Probably not, especially in light of the birds explosive potential to rebound when the water returns. However, even though closed seasons would not be a silver bullet for reversing low populations caused by drought, seasons must be appropriately conservative when population levels are low (see sidebar).

Fortunately, the passion that drives so many of us to need to do something has produced some positive results over the years. The challenge is to resist the urge to affix blame or look for the silver bullet, and to channel our passion and energies into positive attitudes and actions.

But, during periods of low populations, differing philosophies concerning the application of harvest restrictions often result in a drain of time, manpower and money to settle disputes between various interests. This situation is paradoxical. Less risk is affordable during times of low populations and duck managers [and sportsmen] should be more united in efforts to reverse downward trends. Ken Babcock and Rollin Sparrowe, 1989, from, Balancing Expectations With Reality in Duck Harvest Management

We have faced this problem before, such as in the 1960s when drought contributed to driving duck populations to previous lows. We have known for several decades that breeding habitat, and also migration and wintering habitat, were the key to both the short- and long-term welfare of ducks. Rollin Sparrowe and Ken Babcock, 1989, from A Turning Point for Duck Harvest Management

So, with parts of the prairies in droughts grasp, what do we do? We should first take some solace in appreciating that drought is necessary to maintain healthy prairie ecosystems. While in drought, the prairies are, in effect, recharging for the amazing recoveries that we have seen every time the water returned during the last century.
Despite the predictions of doom that arose with each population downturn, most of our duck populations are in good shape relative to the available habitat. To be sure, some species, such as pintails and scaup, require serious additional attention. The wet 1990s, just a handful of years ago, reminded us how productive most of these species can be, and how rapidly their population can bounce back when all habitat components are in place.

We need not just sit back and passively wait for the rains to return, however. We should, for example, be prepared to accept that when ducks are forced into the less productive northern areas, some commensurate reductions in harvest are necessary. We should all work to manage our expectations of this resource. For most of us, the good old days were fewer than five years ago. Duck harvests of the 1990s were comparable to those of the 1970s. However, there are only about half as many hunters now. From that perspective, we have become accustomed to seasons that are twice as good as those of a generation ago. While its reasonable to expect ever faster computers and improving cell phone coverage, it is not reasonable to expect continuous growth in the harvest of the renewable, but finite, duck population. So, if our individual hunting seasons dont go as well as those in recent memory, pausing to reflect on that inescapable reality might help us keep things in perspective (and increase our enjoyment of our time afield).

Finally, as agreed by virtually everyone since the early 1900s, habitat conservation is the key to helping populations through the inevitable droughts. Waterfowl have repeatedly shown that they can take care of themselves within the limits of the available habitat. To sustain and improve the long-term capabilities of those habitats we must aggressively protect existing high-quality habitats. We must increase the available habitat by restoring wetland basins that attract ducks to areas with suitable nesting cover, and establish cover where there are adequate basins that will fill again when the rains return. Recognizing that the millions of acres of Conservation Reserve Program lands were critical to the duck populations of the 1990s, we must focus strongly on singular opportunities such as federal farmland conservation programs. In effect, we must concentrate on keeping and restoring habitat so it can be explosively productive again when the water returns.

On another front, northern areas carry many ducks through the drought years, and there is a growing appreciation of the extent to which these habitats contribute to overall annual production. They are also the primary breeding habitat for some species. In recognition of emerging threats, Ducks Unlimited and its partners are placing increased emphasis on conservation programs in areas such as the western boreal forest and Pacific Northwest.

The passion that we all share for waterfowl can motivate us to accomplish great things. We must focus our energies on actions that will provide the greatest benefits, now and into the future, for the continents duck populations. Lets resolve to work together when we go through the next lean time, each of us contributing in the ways that we best can to address the primary challenges. And lets remember that the most important element in securing the long-term future of duck populations is to secure the long-term future of their habitats.

No one community, no one State, and no one nation can handle this . . . alone. Ira Gabrielson, 1943, from The Ducks, Geese and Swans of North America, by Francis Kortright
. . . a statement as true today as it was 60 years ago.