It’s the Habitat Ecosystem, Stupid
By Dan Nelson, Delta Waterfowl Magazine Editor

“Maintaining waterfowl breeding habitat is the highest priority for the long-term welfare of populations in North America.” –Mississippi Flyway Council.

“It all begins with the habitat.” --Arkansas Wildlife Federation

“It’s the habitat, stupid.” --Magazine editor John Randolph, others

Most duck hunters understand the link between habitat and healthy waterfowl populations. That’s why they generously support the conservation organizations and agencies that have been working to secure waterfowl habitat since the 1930s.

But habitat is a somewhat vague, catchall word, and some who use it are guilty of depicting the goals of waterfowl conservation with paint-by-the-numbers simplicity. They sidestep the tougher questions like, what kind of habitat do ducks require? How much do they need? Where do they need it?

After 70 years, have we put enough habitat in place, and—if not—how much longer before the job is finished?

In reality, the habitats hunters have reached into their pockets to protect are components a larger whole known as an ecosystem. Half to three-quarters of the continent’s ducks originate in the prairie pothole ecosystem, which prior to white settlement consisted of hundreds of millions of acres of tall-, short- and mixed-grass prairie punctuated by countless wetlands and occupied by thundering herds of bison, elk, grizzly bears and wolves.

And ducks. But the prairie ecosystem that once produced sky-blackening flights of ducks has been systematically dismantled until only remnants remain, small islands of grass and potholes dotting a mostly fragmented landscape.

Much of the grass has been converted to crop production, many of the wetlands have been drained, and predators like wolves and grizzly bears have been replaced by foxes, raccoons and skunks.

During the first half-century of waterfowl conservation, our efforts were focused on a single habitat within the prairie ecosystem—wetlands. Sportsmen’s dollars were spent constructing permanent and semi-permanent wetlands in an attempt to drought-proof the prairies.

These well-intentioned efforts—inspired by the great drought of the 1930s—had little impact on duck production because they ignored the fact that an ecosystem is only as efficient as the sum of its parts.

‘So we ask ourselves, ‘how will the dollars invested in dams, dikes and pumps to make marshes bring about the recovery of the hundreds of thousands of mallards that came here (Delta Marsh) every fall?’ --Al Hochbaum, Delta Waterfowl, 1981

Ducks need a variety of wetland types—what biologist Carl Madsen called “a community of wetlands”—to see them through their life cycle. They need breeding water, molting water, staging water and wintering water.

But Hochbaum’s early research showed that when the birds return to their prairie breeding grounds, it’s seasonal and temporary wetlands that are most important. If the prairie ecosystem is a complex machine, small wetlands are the fuel that keeps it humming.

Seasonal and temporary wetlands aren’t glamorous, and often as not they go dry by the Fourth of July. But these little “wet spots” are essential because they provide the high-protein invertebrates nesting hens require for egg development, and ducklings need to get them started in life. Without them, most puddle ducks won’t even attempt to nest.

Yet as recently as the early 1990s, some conservation organizations still dismissed the importance of small wetlands, preferring to focus on dams and dikes.

“US and (if adopted) Canadian farm policy could go much, much further in protecting the 89.6 million acres of required nesting habitat than the cumulative efforts of conservation organizations”. –Arkansas Wildlife Federation.

‘A grassland…is hundreds, literally hundreds, of species of plants woven together in a complex fabric of interdependencies that extend then to insects, to birds, to a carpet of rodents, to predators, and finally to large mammals, of which humans are but one.’ --Richard Manning, Grassland.

As critical as they are for nesting ducks, small wetlands are but one component of the bigger ecosystem. For puddle ducks to nest successfully, they also need grass—lots and lots of grass.

A thoughtful report issued by the Arkansas Wildlife Federation (AWF) was destined to become the most talked-about waterfowl document of 2003. In Findings and Recommendations of the Arkansas Wildlife Federation Duck Committee, AWF said 89.6 million acres of nesting habitat were required in order to provide quality hunting for the state’s wildfowlers.

How did AWF arrive at the figure 89.6 million acres? A 1990’s study by Ron Reynolds of the US Fish and Wildlife Service showed that unless 40 percent of the landscape contains grass, ducks usually fail to achieve high enough nest success to maintain the existing population, let alone expand it.

Not coincidentally, 89.6 million acres is exactly 40 percent of the 224-million-acre prairie pothole region (PPR). In order to achieve the habitat threshold, conservation interests would have to conserve almost 90 million acres of grass across the Dakotas, western Montana and the prairie portions of Alberta, Saskatchewan and Manitoba.

Hens returning to the breeding grounds set up housekeeping where they find the most temporary and seasonal wetlands, but their ultimate success is determined by the availability of large blocks of nesting cover.

Half the ducks that settle in North Dakota take up residence in areas that fall well below the habitat threshold, and there are only a handful of places in prairie Canada that achieve the habitat threshold.

Hens that settle in areas that fall below the habitat threshold have a one in 10 chance of hatching a single duckling.

‘Our analysis suggested that predation processes on the breeding grounds were the primary proximate factors limiting population growth (of the mid-continent mallard).’ --Research conducted by Steven Hoekman, et al.

Native predators like wolves and grizzly bears didn’t pose much of a threat to ducks, but predator populations have evolved rapidly since European settlement, and today the prairies are over-run with small mammals like fox, raccoon and skunk.

Large tracts of grass help insulate hens from these prolific predators by making nests more difficult to locate and by providing alternate prey. Unfortunately, grasslands have been converted to crop production faster than conservationists can save them.

As a result, nest success has fallen precipitously over the years—from 33 percent in the 1930s, to 21 percent in the ‘50s, 15 percent in the ‘70s and just 10 percent in the ‘90s. Scientists tell us 15 to 20 percent is the minimum just to sustain the existing population.

Countless scientists over the last 40 years have identified predation as the cause of ailing nest success, but the prescription most of those scientists wrote called for an increase in the availability of grass nesting habitat, but stopped short of recommending any type of intensive management techniques to deal with burgeoning predator populations.

Some of these scientists questioned the social, political and economic acceptance of intensive management, while others called it a small-scale, band-aid-on-a-broken-arm alternative to the preferred habitat-based solution.

‘There was an undertone of anger in their voices…seething anger, simmering beneath the surface.’ –Outdoor communicator Tony Dean reporting on a (failed) bill in the South Dakota legislature to limit conservation easements to 30 years.

Anyone who thinks retiring productive cropland or taking perpetual easements on grasslands is more socially or politically palatable than checking the growth of the Johnny-come-lately predators that are over-running the prairie landscape hasn’t spent much time on the breeding grounds.

North Dakota has laws governing land acquisitions by government agencies, and a group of vocal South Dakota cattlemen recently tried unsuccessfully to strong-arm a bill limiting conservation easements to 30 years through that state’s legislature.

Canadian farm groups are working to place moratoriums on land purchase by conservation groups. Simply put, most farmers will only tolerate habitat projects at levels below the goals conservation groups set for success.

Most US farmers are finding it more profitable to raise crops than to raise cattle or set aside cropland. According to the AWF report, “…federal subsidies for soybean farmers enable the landowners to realize a net gain of $130.28 per acre,” and it doesn’t take an MBA to calculate that planting soybeans for $130 an acre is more profitable than putting land into CRP for $40 an acre.

It’s unlikely that Congress or Parliament will ever provide enough funding to allow conservation interests to secure the 90 million acres AWF says is necessary to meet our waterfowl production goals. And even if they did, it’s doubtful enough farmers would be willing to take their land out of production to achieve those goals.

In reality, we don’t even know what our habitat goals are. But if we don’t know how much habitat we need, there are two things that should be obvious: First, we can never stop trying; and second, we’ll never be able to restore the ecosystem to its original, pristine condition.

‘Despite nearly a century of propaganda, conservation still proceeds at a snail’s pace; progress still consists largely of letterhead pieties and convention oratory. On the back forty, we still slip two steps backward for each forward stride.’ -- Aldo Leopold.

Because of farm-program incentives and historically low cattle prices, soybean acreage in South Dakota alone increased from 2.7 million acres in 1996 to 4.5 million acres in 2001. Many of those acres were native prairie that had never been broken and had provided grass cover for nesting ducks since before the first Europeans arrived in the 19th century.

According to the National Resources Inventory (NRI), about 1.82 million acres of non-federal grazing lands were converted to cropland in South Dakota alone between 1982 and 1997. With 1.69 million acres enrolled in CRP since 1985, South Dakota actually experienced a net loss in grass cover.

The grassland easements taken the next few years will be critically important because they’ll help keep our heads above water, but it’s unlikely they’ll actually expand the habitat base because grasslands are being broken as fast as we can secure them.

With 2.2 million acres of CRP in the Dakotas set to expire in 2007 and the future of the program in question, we may slip another step or two in the wrong direction.

‘American conservation is, I fear, still concerned for the most part with show pieces. We have not yet learned to think in terms of small cogs and wheels.’ –Aldo Leopold, A Sand Country Almanac.

‘Conservation biologists should be as proficient at eradicating exotic species as they are at saving endangered species.’ --Stanley Temple in Conservation Biology.

‘We still have not got it through our heads that all of life is a complex of checks and balances, driven by both growing and dying, and that anything we do to tilt the system will spin through a place in waves of catastrophe for whole generations.’

--Richard Manning, Grasslands.

The prairie pothole ecosystem is an intricate tapestry of flora and fauna, described by Leopold as, “…one humming community of co-operations and competitions” that evolved “…through ten thousand years of living and dying, burning and growing, preying and fleeing, freezing and thawing…”

A healthy ecosystem is a chain, its members inexorably linked, feeding on one another and in turn keeping each other in balance.

The elimination of any of part of the community or the introduction of exotic species can tip the system hopelessly out of balance. Just as leafy spurge—which has no natural enemies on the prairie—jeopardizes the integrity of the native grasslands, so the expansion of predators that existed in limited numbers—or not at all—has had a dramatic impact on populations of ground-nesting birds.

Our early efforts to drought-proof the prairies were ineffective because they focused on a single habitat and ignored the ecosystem. Will our efforts to save grass and small wetlands produce the desired results if we don’t also address the unnatural mix and density of nest-destroying predators?

Predators are not a sidebar issue, but rather an essential component of a functioning—or malfunctioning—ecosystem. Is it possible to keep the vast prairie duck machine humming without maintaining all the cogs and wheels?

Conservation interests will never be able to “fix” the prairie ecosystem. We must continue raising money for habitat and must keep lobbying Congress and Parliament for programs that conserve our grasslands and wetlands, but we also must recognize that despite our best efforts, some of the most intensively farmed portions of the PPR will never achieve the habitat threshold.

In those areas where we can’t conserve enough grass to increase production with landscape-level solutions, we have two choices:

One option is to write off as a lost cause those ducks that ignore the habitat we’ve conserved, and continue to nest in areas where they very little chance of being successful.

The other is to recognize that the predator community is as much a part of the ecosystem as grasslands and wetlands, and attempt to restore the ecosystem to a more natural state by reducing predator populations where landscape solutions are unrealistic.