A biologist holds an eastern black rail in southern Louisiana coastal wetlands. Photo by Brian Hires/USFWS
The eastern black rail is one of the planet’s most wide-ranging migratory birds, with many populations flying thousands of miles annually to marshlands across the United States and Latin America. It uses salt marshes, shallow freshwater marshes, wet meadows and other types of flooded grassy vegetation across this broad range for cover, forage and nesting.
Following population declines of as much as 90 percent, the eastern black rail was proposed for protection as threatened under the Endangered Species Act (ESA) in 2018. Primary threats are the loss of its habitat across the United States and Latin America.
The bird is elusive, however. So much so that it even featured in the birding comedy The Big Year, as the only bird in North America the protagonists were unable to spot. It is so elusive that even dedicated biologists have difficulty locating and studying them, meaning that little had been known about them to date.
So how did the Service go about evaluating the status of this elusive wetland-loving bird?
Given that nearly half of all species protected under the ESA are wetland-dependent in some fashion, this is an important question for more than just the eastern black rail. Wetlands are home to countless fish, wildlife and plants—many of which are of significant commercial and recreational importance. These habitats are also critical to people. Wetlands recharge groundwater, mitigate flooding, provide clean drinking water, offer food and fiber, and support cultural and recreational activities.
The answer to the question involves some of the most highly visited Service webpages. Every week, thousands visit the Service’s National Wetlands Inventory (NWI) pages for detailed science, maps and statistics that are vital to their livelihoods. These stakeholders include scientists, city planners, citizens, landowners, developers, and decision-makers from local, state and federal governments, state wildlife agencies, conservation groups, industries and universities. Few outside this group of power users, however, know about this resource and its ability to bring American wetlands, wildlife and natural resources issues alive to anyone with a computer.
The NWI was initiated in 1974 to create the nation’s first comprehensive inventory of its wetlands and to monitor changes to ecosystems, wildlife habitats and natural resources.
Biologists with Audubon Louisiana gather rail data. Photo by Brian Hires/USFWS
NWI’s geospatial dataset captures wetlands from coast to coast, providing information on water fluctuations, vegetation and soil type, salinity, proximity to lakes and rivers, and human modifications, such as ditching. Among other things, this allows biologists to assess habitat for wildlife and develop strategies for conserving species. It also allows planners and landowners to make better-informed decisions, which not only protect their bottom line but also support conservation.
The development of the eastern black rail Species Status Assessment (SSA), a foundational scientific document that informed the rail’s ESA decision, serves as a powerful example of the role key factors play in ESA work. To determine the status of the rail, Service physical scientist Rusty Griffin used NWI data to analyze its habitat. The dataset helped him identify the rail’s habitat needs and assess the current conditions of available habitat within the species’ range — all important SSA requirements.
To determine possible future habitat conditions, Griffin used data from NWI Wetlands Status and Trends reports. These reports represent some of the most important scientific and conservation documents on American wetlands. Wetlands Status and Trends reports, renewed every five to 10 years, have catalyzed billions of dollars worth of wetlands restoration and conservation efforts across America. They helped turn around the rapid loss of wetlands and related wildlife that began in the 1800s and continued until the 1950s. Using the Wetlands Status and Trends data, Griffin worked with FWS biologist Whitney Wiest to develop habitat projection models.
The resulting models predicted future population numbers for the eastern black rail by projecting extinction and colonization rates for sites currently occupied by the rail. The result was a science-based finding that the rail faced the possibility of extinction in the foreseeable future, spurring conservation actions and research that have had meaningful impacts.
While there is much more to be learned about the eastern black rail and changes to the diverse wetland habitats that they call home, the NWI will no doubt play a central role in these efforts.
“Conservation of wetlands is critical for countless species, especially long-distance travelers like migratory birds and waterfowl, and conservation begins with good science,” says Megan Lang, NWI’s chief scientist. “Maps of important habitat and information on how that habitat is changing, are essential for supporting conservation across large areas.
“Good science and resources like the NWI, Wetlands Mapper, and Status and Trends reports, which that are available to stakeholders and citizens at any time and outline…are also the foundation of conservation partnerships, sustainable planning and endangered species conservation,” adds Lang.
“After all, you can’t protect what you don’t know exists,” Lang says.
BILL KIRCHNER, Science Applications, Pacific Region, and BRIAN HIRES, External Affairs, Headquarters