This is the first in a three-part report on prairie Canada

Most of ducks harvested in the United States come from a place called the Prairie Pothole Region (PPR).  Although it encompasses just 10 percent of North America’s duck-breeding habitat, the PPR produces roughly 8 out of every 10 mallards killed in high-harvest states like Arkansas, Louisiana, Minnesota, North Dakota and Texas, and contributes ducks to the coastal flyways as well.

Two-thirds of the PPR—a.k.a. “the duck factory”—exists in Canada, and at one time the overwhelming majority of the region’s ducks originated there.  While the prairies of Manitoba, Saskatchewan and Alberta still attract more breeding ducks than anyplace else on the continent, prairie Canada’s contribution to the fall flight is a shadow of what it once was, and the situation isn’t likely to change anytime soon.

The Canadian portion of the PPR once attracted nesting ducks at a rate commensurate with its size: According to the breeding population survey conducted by the US Fish and Wildlife Service and Canadian Wildlife Service, two-thirds to as many as three-fourths of the mallards that nested in the traditional survey area back in the 1950s settled in prairie Canada.

That’s no longer the case.  The last time the Canadian prairies attracted even half the mallards in the breeding population was 1982, and during the duck boom of the 1990s only 4 out of 10 mallards set up housekeeping there.

Prairie Canada’s ability to attract and produce mallards has been steadily shrinking for half a century, and the billion-dollar-plus investment by conservation interests has failed reverse the trend. 

This issue of Delta Waterfowl Magazine will document Canada’s long-term decline in productivity and examine the frustrations of waterfowl managers struggling to slow the ongoing loss of habitat responsible for our north-of-the-border production woes. 

This may be a painful journey for those who believe Canada is a pristine wilderness teeming with habitat and producing ducks at its once-glorious pace, but before any problem can be corrected, we must first acknowledge that a problem exists.

“Prairie Canada is critically important to the future of ducks and duck hunting on the continent,” says Delta President Rob Olson.  “Thanks to a prolonged wet cycle and the Conservation Reserve Program, the US was able to pick up the slack for prairie Canada during the 1990s, but our best hope for a return to ‘the good old days’ of duck hunting lies north of the border, where 70 percent of the duck factory exists.”

How Good Were ‘The Good Old Days’?

Gordon MacQuarrie wrote of “the big flight”.  Others talk of “the freeze-up flight” or the “northern flight”.  Whatever you call it, the sight of new ducks descending from the sky like manna from heaven can make a waterfowler’s heart turn cartwheels.

Anyone who wasn’t hunting ducks back in the days when Eisenhower was president and Elvis was king can only imagine the fall flights of the 1950s.  Old-timers recall endless waves of ducks washing across the horizon as far as the eye could see for days on end.

Scientists dismiss such talk as anecdotal evidence, and well they should. After all, objects viewed through the rear-view mirror of time often appear larger than they actually were.              But while scientists can challenge the reliability of 50-year-old memories, it’s difficult to argue that Canada’s output of ducks isn’t what it was half a century ago.

There is no smoking gun in this assessment, no peer-reviewed scientific paper that spells out Canada’s waning productivity in indisputable terms.  What does exist is a large body of evidence pointing to the inescapable conclusion that prairie Canada isn’t producing ducks like it once did.

Breeding Population has Dwindled

One way to examine Canadian duck production is to decouple prairie Canada from the rest of the duck factory and compare the number of breeding mallards—one of the most reliable numbers scientists have at their disposal—that settled in the prairie provinces decade by decade since the first breeding population survey was conducted (see chart).

Between 1955 and 1958, an average of 6.9 million mallards nested in the prairie portions of Alberta, Saskatchewan and Manitoba.  There were almost as many pintails as mallards back in those days, and with nest success twice what it is today it’s easy to understand why old-timers have fond memories of sky-blackening fall flights of ducks.

Duck numbers went in a tailspin when the breeding grounds went dry in the early 1960s, but rebounded when conditions improved in the ‘70s.  Four million May ponds is considered wet in prairie Canada, and in 1970, ’71 and ’72 the provinces averaged 4.3 million ponds and attracted an average of 5.4 million nesting mallards.  Wetland conditions were even better between 1974 and 1976, with prairie Canada averaging 5.4 million May ponds but attracting only 4.5 million mallards a year.

The late-‘70s breeding population drop could suggest that significant landscape changes in the Canadian prairies were already underway or it could reflect a decline in productivity that typically occurs during the late stages of a wet cycle.  

Wetland conditions weren’t all that good in the 1980s, but prairie Canada had more than 4 million May ponds in 1985 and 1986.  Despite that brief wet spell, the mallard breeding population in the prairie provinces dipped, and the 2.3 million mallards that settled there in 1985 was the lowest total since the spring breeding survey was launched in 1955.  That dubious record would be broken just four years later when only 1.9 million mallards arrived on the prairie breeding grounds.

“As painful as they can be for duck hunters, droughts are a necessary part of nature’s cycle,” says Olson.  “Drought recharges the little temporary and seasonal wetlands so critical to duck production.”

Wet and dry cycles are as predictable as death and taxes, and sure enough moisture returned to the prairies in summer of 1993.

The water came back, but the ducks didn’t—at least not at their previous levels. 

Between 1994 and 1999 prairie Canada averaged 4 million May ponds, but it attracted an average of only 3.5 million mallards, barely half the number that settled there in the 1950s and significantly fewer than the ‘70s.

But…but…but…you’re saying, what about those memorable hunting seasons in the ‘90s, the record breeding population, the 105-million bird fall flight and all-time high harvests?  Don’t they prove that Canada is still kicking out ducks like it did in the old days?

It’s true that duck hunting improved dramatically in the ‘90s, but as we’ll see, an increasing percentage of nesting mallards abandoned Canada in favor of the US, where the Conservation Reserve Program (CRP) provided large blocks of nesting cover and the Clean Water Act, the ducks stamp and the Swampbuster provisions of the farm bill preserved wetlands.

Percentages Steadily Falling

Canada’s waning productivity is even more dramatic when viewed as a percentage of the total breeding population.

In the late 1950s, 69 percent of the mallards counted in the traditional survey area settled in prairie Canada.  In the first half of the 1970s, the percentage of mallards nesting in prairie Canada was 57 percent, and by the second half of the ‘70s it averaged 53 percent.

During the wet cycle of the ‘90s, only 39 percent of the mallard breeding population took up residence in prairie Canada.  In other words, 7 out of every 10 acres of the duck factory exist in Canada, but by the ‘90s only 4 out of every 10 mallards settled there.

In the 28 years between 1955 and 1982, prairie Canada attracted 50 percent of the mallards in the breeding population 19 times, including seven years when more than 60 percent of the breeding mallards nested there. 

Since 1982 prairie Canada has failed to attract 50 percent of the mallards in the spring survey even once, and in 12 of the last 17 years fewer than 40 percent of nesting mallards have settled in the once-productive region.

“That’s a pretty powerful piece of information,” says Ron Reynolds, who heads up the US Fish and Wildlife Service’s Habitat and Population Evaluation Team (HAPET) office in Bismarck, ND.  

The US Picked up the Slack

But if Canada didn’t produce the ducks of the ‘90s, where did the birds come from?  A lot of them apparently came from the U.S.   During the 1960s, the average number of mallards that nested in North and South Dakota was just 610,000.  Between 1994 and 1999 the average number of nesting mallards that settled in the Dakotas was 2.2 million. 

Add in the sliver of northeastern Montana that’s part of the surveyed U.S. pothole region and that number jumps to 2.6 million—about four times more than settled in the US portion of the duck factory during the ‘60s.

In fact, if Minnesota’s breeding population survey is included, the US pothole region actually attracted more breeding mallards than prairie Canada in 2001 and 2002.  And when productivity is factored in, the US may have contributed as many or more ducks than Canada several times since 1994.

Research conducted by Reynolds showed that CRP alone contributed 2 million ducks to each of the fall flights from 1992 to 1997; those are ducks that wouldn’t have existed without CRP. 

Factor in the wetlands saved by the Wetlands Reserve Program (WRP), Swampbuster, the Clean Water Act and the federal duck stamp program, and it’s easy to understand how the US was able to pick up the slack for Canada.

According to research conducted by Fish and Wildlife, the US portion of the PPR attracts three times the density of breeding duck pairs as does the Canadian PPR. And a brood index developed by the Fish and Wildlife Service shows that hens nesting in the prairie provinces produced fewer broods than hens nesting in the US.

“That’s a staggering shift in production to south of the border,” says Delta’s
Scientific Director Dr. Frank Rohwer.  “I doubt any of the 50 some biologists I know would have predicted such a change in duck production.”

Make no mistake, Canada contributed ducks to the memorable flights of the ‘90s, but it produced far fewer ducks than it did in the ‘50s and ‘70s, and only slightly more than it did in the ‘60s (see related article).

Research Confirms Declining Productivity

Scientists say nest success—the percentage of nests that hatch at least one egg—must be about 15 percent just to maintain the existing population of ducks. 

Wendy Beauchamp compiled the available prairie nesting studies and found a shocking trend in duck nest success.  In the 1930s, prairie ducks had 33 percent nest success, but it had slipped to 21 percent by 1955, to 15 percent by 1972 and by the 1990s it was down to 10 percent.           

“Most waterfowl biologists suspected that nest success had dropped, but the Beauchamp study really made it clear how much nest success had declined,” says Dr. Rohwer.

But if nest success dropped across most of the pothole region, it got a huge boost from CRP on the US side of the border.  The Reynolds study (1992-97) showed that ducks nesting in CRP enjoyed a population-expanding 22 percent nest success, and as a result CRP added 2 million incremental ducks to the fall flights of the ‘90s.

But nest success across much of Canada continues to fall short of the level necessary to maintain the existing population.

A 1993-2000 assessment conducted by Ducks Unlimited’s Institute for Wetland and Waterfowl Research (IWWR) confirmed that mallards failed to achieve population-expanding nest success levels on all but a handful of areas, including many where significant management dollars had been spent.

The study assessed nest success on 27 sites—nine low-treatment, nine medium-treatment and nine high-treatment—across the three provinces during the 1990s “duck boom”. 

Mallard nest success was below 10 percent on 19 of the sites; and the percentage of mallard hens that died exceeded the percentage of hens that were successful on 19 of the 27 sites.

In 1998 and 1999, years when the mallard harvest set all-time records, mallard nest success on the eight Canadian sites monitored by IWWR ranged from one to nine percent.

With nest success below 10 percent and hen mortality from 25 to 37 percent, many of those high-treatment areas qualify as “population sinks”, which means more ducks arrive in the spring than migrate south in the fall.

IWWR called the 1998 results “sobering” and admitted that “predation negatively influenced production at all sites…”

“Many of us wondered how ducks could persist in southern Manitoba and other parts of prairie Canada when nest success estimates regularly fell below five percent,” Rohwer says.

One of Delta’s students, Dan Coulton, has been conducting research in the Minnedosa area of Manitoba.  Of the 200 duck nests monitored by Coulton in 2004, only one was successful. 

Nest-raiding predators—primarily fox, skunk and raccoon—were mostly to blame for the abysmal nest success at Minnedosa in recent years.

If mallards that nest on managed landscapes failed to consistently achieve population-expanding nest success during one of the most prolonged wet cycles of the 20th century, what are the chances of success for birds nesting on the more than 95 percent of the Canadian landscape that isn’t managed?

Problems Nothing New

Canada’s production woes are nothing new. Research published 40 years ago suggested that even back then conditions leading to high duck production occurred in 4 or 5 years out of 10 under pristine  conditions—which today are exceedingly rare—and only 2 or 3 years out of 10 in habitats altered by agriculture.

During 1982 to 1985, Ray Greenwood of the Northern Prairie Wildlife Research Center in North Dakota studied duck nesting in high-density duck areas of the PPR in Canada.  What he found is that mallards and pintails achieved the 15 percent nest success necessary for maintaining stable populations in just 8 out of 31 area-years, and blue-winged teal, shovelers and gadwalls achieved the 20 percent necessary to maintain their populations in just 4 of 31 area-years.

Back in the ‘80s, 77 percent of all nests initiated failed as a direct result of predation, and hen mortality from predation was also high.

Prairie Canada is Broken

When most hunters think of prairie Canada, they picture a vast, pristine wilderness virtually untouched by man. In realty, the Canadian portion of the breeding grounds is intensively farmed and ranched. 

According to figures provided by the Prairie Habitat Joint Venture (PHJV), about 120 million acres of the Canadian PPR exist in the prairie portion of the three provinces, the rest being parkland  Of those, about 63 million are tilled, 8 million are in hayland and 50 million are natural (native prairie, wetland vegetation and woodlands).

PHJV says increases in acres of tilled uplands and drained wetlands have reduced the Canadian PPR’s duck production capacity by 6.7 percent since 1971.  While some cropland has been converted to hayland and pasture, these gains seem to have been offset by the ongoing loss of wetlands and a hefty 30 percent increase in the number of cow/calf units utilizing those pastures.  Like farmers, livestock producers also must squeeze every bit of profitability from the land.

Modeling done by Michael Watmough of CWS shows that since 1971 prairie Saskatchewan has lost 6.69 percent of its wetland area, prairie Alberta has lost 4.59 percent and Manitoba parkland has 7.6 percent fewer wetland acres. 

It should be noted that Watmough actually provided wetland loss rates for 1985 to 1999, and concluded that wetland losses were constant from the 1970s to the present.  A PHJV documents suggests his wetland-loss estimates are believed to be conservative.

The resulting loss in duck carrying capacity ranges from 4.1 to 11.4 percent, but is as high as 90 percent in localized areas (the Royal Municipality of Leroy in Saskatchewan is an example), according to PHJV reports.

Estimates of wetland losses across prairie Canada since European settlement vary from 40 percent to as high as 71 percent, a figure that was documented by the National Wetlands Working Group for Minnedosa in Manitoba.

Reversing those trends is the challenge facing conservationists.

“The Canadian portion of the duck factory is broken, and fixing it will require the combined efforts of waterfowl managers and conservation organizations, and the support of duck hunters,” says Olson.

The summer issue of Delta Waterfowl Magazine will examine efforts to correct prairie Canada’s duck production woes, looking at measures that have been successful and some that have not.

Prairie Canada is critically important to the future of ducks on the continent.