Drought and the prairie cycle


". . . 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!? Who's to blame for this? We've got to fix this, and right now, before it's 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 "déjà 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?

Taking a look at history

In the mid-1800s, settlement first scratched the surface of the expansive landscape of prairie grasslands and potholes that fledge so many of North America's 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. prairies — just 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 Canada's 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.

The necessity of drought

Drought is a necessary evil.

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 can't control. So, let's 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.


Material from Ducks Unlimited.

Visit the web site at www.ducksunlimited.org