Vanishing Wings

Many of North America's bird species are declining dramatically. Successful efforts to conserve waterfowl populations can serve as a model for recovery.

By Tom Moorman, PhD


Imagine standing in a vast hardwood forest in the Wisconsin Territory in May 1848, just weeks before the state was admitted into the Union. The forest is a cacophony of birdsong. In the distance, you hear an approaching sound, at first hard to place. Then, as the sound draws closer, it rises to a roar, much like a mighty gust of wind, but there is only the slightest southerly breeze on this fine spring day. Suddenly, the bright sunshine is eclipsed, and the source of the sound is upon you—millions of passenger pigeons returning en masse to their traditional nesting grounds.

Now imagine yourself 66 years later, an old-timer, having moved from Wisconsin to Cincinnati, Ohio. It is 1914, and at the local zoo a single bird sits in a cage. She is old, the last of her species. Her imminent death will mean extinction for the passenger pigeon, which just decades earlier may well have been the most abundant bird species ever to grace the skies of North America. Conservation scientists and naturalists still debate the causes of this great loss, but it's likely that two factors interacted: overharvest by commercial hunters and conversion of forests to agricultural fields to feed the nation's growing human population. The debate over what caused the passenger pigeon's demise is not frivolous. In that discussion are lessons that can help us prevent the decline or extinction of other species.

Today, more than a century later, many of our bird species are experiencing similarly precipitous declines. In 2019, a team of scientists, led by Dr. Ken Rosenberg of the Cornell Laboratory of Ornithology, published a paper in the prestigious journal Science. That paper reported that North America has lost nearly 3 billion birds since 1970. The scientists analyzed long-term data sets as well as radar assessments of bird biomass during migration. Their research revealed that populations of many bird species—in 38 taxonomic families—have suffered significant declines. However, the authors also noted that some families of birds showed positive population trends during the study period. In fact, wetland birds increased by 13 percent, led by a 56 percent increase in waterfowl.

"Waterfowl were one of the bright spots in the results of our study, with a healthy increase in their population," Rosenberg says. "We attribute the increase to the success of conservation efforts, often funded by hunters through conservation organizations like Ducks Unlimited, which have protected and restored substantial habitat for these birds throughout North America. Waterfowl conservationists and supporters have shown us a path forward to stabilize and recover populations of other species that have declined. Now we must act to bring to bear the same passion and science-based planning—and secure funding—to recover other bird populations and conserve all of North America's bird diversity."

Since 1986 the North American Waterfowl Management Plan (NAWMP) has guided science-based investments in habitat protection and restoration across the United States, Canada, and Mexico to help sustain and increase waterfowl populations. A significant portion of the funding for those conservation efforts has been and continues to be provided by hunters and other waterfowl conservationists through the purchase of Migratory Bird Hunting and Conservation Stamps (federal duck stamps), state waterfowl stamps, hunting licenses, and contributions to conservation organizations like DU.

The North American Wetlands Conservation Act (NAWCA), which was established by Congress to serve as a funding mechanism for NAWMP, has also been a crucial source of money to pay for conservation work. Since its passage in 1989, NAWCA grants totaling more than $1.7 billion have leveraged $3.6 billion in matching funds and another $1.4 billion in nonmatching funds from thousands of partners. These contributions have far exceeded matching requirements, allowing for implementation of over 2,900 projects on more than 30 million acres of wetlands and associated uplands across North America. Ducks Unlimited Inc. (DU), Ducks Unlimited Canada (DUC), Ducks Unlimited de México (DUMAC), and Wetlands America Trust (WAT) have been strong partners in the NAWCA program since its inception.

Mother Nature has also benefited waterfowl populations in recent decades, providing abundant water on crucial nesting areas in the Prairie Pothole Region. In addition, some waterfowl species, such as snow geese, have benefited from the expansion of agriculture on migration and wintering areas, which has increased the birds' survival and breeding productivity. However, current waterfowl populations would not exist without the passion and dedication of hunters and other conservationists who have generously given their time and resources to conserve the birds' habitats in high-priority areas across the continent.

Although many waterfowl populations are currently healthy, it's important to note that not all species are faring well, and wetlands and associated upland habitats are still at risk on many important landscapes. Admirers of the northern pintail and lesser scaup are painfully aware that these species' populations have languished well below NAWMP population goals in recent years. Scientists are still exploring possible causes for the lesser scaup's decline, but northern pintails appear to be suffering from the loss of native grasslands and changes in agricultural practices in their core breeding range in the Prairie Pothole Region. The decline of these two popular waterfowl species serves as a reminder that our work as conservationists never ends. Crucial waterfowl habitats will always be at risk, and our commitment and resolve to conserve them must never falter.

As noted in the Science article, conservation efforts completed under the NAWMP umbrella are important for many other bird species in addition to waterfowl. These include grassland birds, which have collectively suffered the largest population decline of any bird group. Given the importance of the Prairie Pothole Region to breeding waterfowl, the protection of native prairie grasslands with high densities of wetlands is among DU's highest conservation priorities. These same high-priority landscapes also support a suite of declining grassland birds, including the chestnut-collared longspur and Sprague's pipit. Both of these songbirds are grassland obligates, meaning they only breed in native grasslands and specifically seek out unique short- to mid-grass prairie that is neither too barren nor too densely vegetated with grasses and forbs. They are true grassland specialists, and both species can be found in native prairie that has been protected by DU, DUC, and WAT, either through direct purchase or via conservation easements secured from ranchers and others who sustainably manage native grasslands.

american-avocet

American Avocet

 

Shorebirds also benefit directly from waterfowl habitat conservation. These diverse and highly recognizable species, many of which have also suffered steep population declines, share many habitats with ducks and geese throughout the year. For example, the lesser yellowlegs, a medium-sized shorebird with a slightly upturned bill, nests on boreal wetlands from Canada's James Bay to western Alaska. For more than two decades, DU, DUC, and WAT have worked in the Boreal Forest with a broad coalition of partners, including First Nations, federal and provincial agencies, foundations, and corporations, to protect vital wetland systems and establish sustainable land-use plans in areas where natural resource development will take place. These efforts will help sustain not only healthy breeding populations of waterfowl but also shorebirds like the lesser yellowlegs and many other boreal bird species.

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Lesser yellowlegs often share wetlands and winter-flooded rice fields with ducks and geese.

 

During migration and winter, lesser yellowlegs frequent shallow wetland impoundments and winter-flooded rice fields managed by farmers with assistance from DU and its partners. Farther south, in Mexico, these birds spend the winter in mangrove swamps and shallow seasonal wetlands in that country's interior highlands, where DUMAC is actively working to conserve these important waterfowl habitats.

blackpoll-warbler

Blackpoll warblers visit a variety of waterfowl habitats during their epic migrations.

 

Even the smallest migratory birds have much to gain from waterfowl habitat conservation. A good example is the blackpoll warbler, which has declined by more than 50 percent during the past 40 years. Weighing only half an ounce on average, these diminutive songbirds nest across the vast Boreal Forest and migrate in fall along the eastern seaboard or over the Atlantic Ocean and Caribbean to wintering areas in South America. During their return migration in spring, some refuel on insects in DUMAC's mangrove forest restoration areas in northern Yucatán, and then make the nonstop 500- mile flight across the Gulf of Mexico before flying north through the continent's interior to their boreal breeding grounds. Along the way, many of these birds likely stop to rest and refuel on DU projects in the Mississippi Alluvial Valley, where forested wetlands have been restored on flood-prone former agricultural lands.

"The Migratory Bird Treaty Act (MBTA) has been beneficial to waterfowl conservation across their range in North America," Rosenberg says. "Reversing declines in species like the blackpoll warbler, whose annual movements cross multiple countries from Canada to several in South America, will require strong international cooperation and strong protections under the MBTA. We must now ensure continued and increased attention and focus on these species like the blackpoll warbler to achieve stable, sustained populations through appropriate conservation solutions."

It's clear that many kinds of migratory birds benefit directly from the conservation of wetlands and other waterfowl habitats. Supported by Ducks Unlimited's three affiliates and WAT, DU's work is delivered in cooperation with an array of conservation partners. That is the model upon which NAWMP was founded. This same approach can also be applied to successfully reverse negative population trends among other North American bird species. Of course, conserving the diverse habitats on which these species depend is a lofty goal, and funding will have to be increased dramatically, from a variety of sources.

Wetland and waterfowl conservationists have a deep sense of commitment to give back to the birds that so greatly enrich our lives. Sustaining waterfowl and their habitats, which also benefits other bird populations, is our passion, but ensuring that future generations can witness flocks of waterfowl winging south on a strong north wind or hear the boisterous chorus of birdsong on warm spring mornings is our obligation. While much work remains to be done, we should also reflect on what we have accomplished and thank the passionate conservationists who have generously supported our work for decades. Going forward, let's stay the course and invite more supporters to join us to increase the scope, scale, and rate at which we conserve wetlands and other important wildlife habitats across North America.


Dr. Tom Moorman is Ducks Unlimited's chief scientist. He is based at DU national headquarters in Memphis.


Waterfowl Research Foundation Supports Science-Based Conservation

Science is the backbone of Ducks Unlimited's mission, and it's what makes the organization the leader in wetlands and waterfowl conservation. The critical partners who fund our research efforts help lay the foundation for our future successes. The trustees of the Waterfowl Research Foundation (WRF) understand the importance of investing in strong research-driven conservation programs.

During the past five decades, WRF has provided close to $6 million in funding for research on Atlantic sea ducks, American black ducks, brood surveys, nesting conditions in the US Prairie Pothole Region, and the linkage between Canada's eastern Boreal Forest and waterfowl in the Atlantic Flyway. Through the foundation's investment, DU is able to protect the right kind of habitat in the right places, securing the future for North America's waterfowl populations.

In addition to the foundation's philanthropy, many of the trustees are longtime DU supporters themselves. The Waterfowl Research Foundation's past and current leadership has set a strong precedent for ongoing support of DU's continental conservation efforts.

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Photo © David Tipling Photo Library