Audubon Center at Riverlands: A Hemispheric Crossroads for Bird Migration and Bottomland Forest Conservation

The Mississippi is well worth reading about. It is not a commonplace river, but on the contrary is in all ways remarkable. 

— Mark Twain, Life on the Mississippi 

The Mississippi River is a globally significant ecosystem, often referred to as the “lifeblood of America” for both people and birds. Its vast watershed drains 41 percent of the continental United States, touching three-fifths of the nation’s states and two Canadian provinces. It forms the core of the Mississippi Flyway, a central migratory passageway supporting nearly 60 percent of North America’s migratory bird species. Despite this ecological importance, the river faces increasing pressures and was recently named America’s most endangered river. Long before this designation, Audubon and its partners have been working to restore, rehabilitate, and reimagine this iconic system—efforts that are now more urgent than ever. 

Just north of St. Louis, the Audubon Center at Riverlands sits at one of the most important migratory stopover sites along the Mississippi River. Nestled within the 3,700-acre Riverlands Migratory Bird Sanctuary, the Center and the surrounding landscape lie at a hemispheric crossroads for birds flying between the Arctic, the Mississippi River basin, the Gulf, and beyond. With more than 300 bird species recorded here, Riverlands is not just a sanctuary; it is a global lifeline for migratory birds. 

The Bird Migration Explorer reveals how connected the Center and the surrounding landscape truly are across the entire western hemisphere. Birds observed at Riverlands link this floodplain to more than 45 countries and territories from northern Canada to the southern reaches of Chile and Argentina. Data from more than 100 tagged species show connections like the Blackpoll Warbler’s connection to Cuba, the Cerulean Warbler’s ties to Venezuela, the Common Nighthawk’s reach into western Brazil, and the American Golden-Plover’s presence in Uruguay. And these birds aren’t simply passing through—being observed at Riverlands highlights the region’s role as a critical gateway, linking breeding and wintering grounds. It provides essential places for birds to rest, refuel, breed, and survive as they connect ecosystems across the Americas. 

At the foundation of this landscape for many species are bottomland hardwood forests—rich, seasonally flooded woodlands that once stretched broadly along the Mississippi’s banks. Today, more than 50 percent of these forests have been lost or degraded due to development, altered hydrology, and the introduction of invasive species, such as reed canary grass and Japanese hops, as well as diseases like Dutch Elm Disease and emerald ash borer since 1989. Although fragmented and diminished, these forests are more vital than ever, providing critical habitat in a landscape where such resources are increasingly scarce. 

For many landbirds, the Upper Mississippi’s bottomland forests are everything. They provide refuge and resources in a fragmented landscape, including a steady supply of food and the appropriate forest structure needed to raise their young safely. Regional species of interest, such as the Red-shouldered Hawk, Warbling Vireo, and American Redstart, depend on these forests for nesting, molting, foraging, and safe passage during migration. Cavity excavators such as the Red-headed Woodpecker rely on standing dead trees to create nesting sites. Once abandoned, these cavities can become prime real estate for Prothonotary Warblers, which nest above shallow water as the only cavity-nesting warbler in the East. 

From Riverlands, Audubon scientists lead long-term efforts to monitor, protect, and restore these declining forest habitats. According to the 2025 State of the Birds report, populations of eastern forest birds have decreased by 27 percent since 1970. While some species in mature forests are doing better than those in disturbed forests, the losses are widespread. This makes local conservation essential to bending the bird curve back toward stable populations. 

This work began in 2014 with the launch of a bird-monitoring program in the St. Louis region. It has since expanded northward, spanning from the confluence of the Mississippi and Missouri Rivers to the Twin Cities of Minneapolis-St. Paul. Field teams conduct annual breeding bird point counts and habitat and vegetation surveys to build a clearer picture of how birds interact with bottomland forests over time. These surveys reveal which habitat features—such as canopy height, tree density, and tree species composition—best support thriving bird communities. 

According to Tara Hohman, conservation science manager for Audubon Riverlands, these surveys are the baseline for regional conservation. “The value of this work has been critical to influencing the management of these forests for wildlife, along with forest health. Helping to build a system that benefits the ecology on a landscape level.” 

These insights guide conservation actions. Across 70 river islands and conservation areas, Audubon and partners—including the U.S. Army Corps of Engineers, U.S. Fish and Wildlife Service, Tribal Nations, and state agencies—are removing invasive reed canary grass, replanting native species like swamp white oak and black willow, and restoring the layered forest structure that birds need to thrive. To date, more than 3,000 acres of the floodplain forests in the region have been enhanced, with more than 160,000 trees planted. 

Looking ahead, Audubon aims to deepen and expand this work by continuing restoration and monitoring at current sites while filling critical data gaps elsewhere along the river. By understanding what makes a bottomland forest productive for birds and applying these lessons at scale, we can reverse decades of habitat loss and help stem population declines of forest-dependent species.  

For Hohman, this work is important for the future of local breeding birds and those migrating to other corners of the hemisphere. “Through this work, we strive to improve and restore bottomland forests for the health of the habitat and the birds that call it home. While we continue to fine-tune our understanding of the needs of our breeding birds within this system, we also hope to establish an understanding of the migratory bird needs and use of this special habitat.” 

As the Mississippi winds past Riverlands, the floodplain forest pulses with life. This stretch of river is more than a stopover—it’s a continental epicenter, where decades of work to restore bottomland forest habitat are shaping a brighter future for birds. In this critical stronghold, Audubon is stepping up to the responsibility and the opportunity to ensure that future generations of birds—and people—continue to thrive.