Interior Least Tern Taken Off Endangered List

The U.S. Fish and Wildlife Service (USFWS) announced January 12 that the interior least tern has officially been taken off the endangered species list.

When the interior least tern was listed under the Endangered Species Act (ESA) in 1985, there were fewer than 2,000 birds and only a few dozen nesting sites scattered across a once-expansive range that covered America’s Great Plains and Lower Mississippi Valley. Today, the agency says, there are more than 18,000 interior least terns at more than 480 nesting sites in 18 states.

The action is important to waterways interests because the job of protecting nesting sites of the interior least tern was given by Congress to the Corps of Engineers. To protect threatened species like the interior least tern, along with fish species on the list, like the pallid sturgeon, the Corps made changes to waterways structures on the Missouri River and elsewhere. Some property owners along the Missouri River have successfully sued the Corps, charging that its species-protection measures interfered with its flood control mission to the point where it made floods more frequent and worse.

The USFWS said that according to the best available science, the efforts of local, state and federal stakeholders across the interior least tern’s 18-state range have helped ensure that populations are healthy, stable and increasing into the foreseeable future. The tern will continue to be protected under the Migratory Bird Treaty Act.

“The Trump administration and Secretary [of the Interior David] Bernhardt are committed to the recovery of our nation’s imperiled species,” U.S. Fish and Wildlife Service Director Aurelia Skipwith said. “Dozens of states, federal agencies, tribes, businesses and conservation groups have worked tirelessly over the course of three decades to successfully recover these birds.”

To help ensure the species’ continued success, the Corps, which has jurisdictional authority over much of the interior least tern’s range, has made formal post-delisting monitoring and conservation commitments that encompass about 80 percent of the breeding population.

In 2005, the Corps coordinated a range-wide monitoring event that confirmed tern populations were increasing over the previous two decades. The Corps also funded, with the assistance of USFWS, the development of a habitat-driven, range-wide population model for the species. This complex model, developed with the American Bird Conservancy, considers interior least tern status and population dynamics with and without continued management at local, regional and range-wide scales across a 30-year period.

“The U.S. Army Corps of Engineers is absolutely honored to play a role in a partnership that serves as a model for the potential delisting of other species in the future,” Maj. Gen. Diana Holland, commander of the Mississippi Valley Engineer Division, , said. “For over 30 years, we have partnered with the Service to monitor, conserve and recover this endangered species along the Lower Mississippi River. That partnership demonstrates that, through collaboration, we can protect and recover an endangered species while continuing to provide critical navigation and flood control benefits to the nation.” 

“Without the commitment and partnership of the U.S. Army Corps of Engineers, the recovery of the interior least tern would not have been possible,” USFWS Regional Director Leopoldo Miranda said. “The Corps has implemented conservation measures over the course of decades that have improved habitat for terns along some of America’s largest rivers, such as the Missouri and the Mississippi, and these actions have been central to the tern’s recovery.”

“Today’s announcement is welcome news for conservationists in Wyoming and around the country,” Sen. John Barrasso (R-Wyo.) said. “After years of hard work and collaboration, the interior least tern will be officially removed from the endangered species list. Since its listing in 1985, Wyoming, Colorado and Nebraska have worked in good faith with landowners, conservation groups and the federal government to preserve critical habitat and recover this bird. The Platte River Recovery Implementation Plan played a critical role in this success story. It now serves as a model for future conservation efforts.” 

Least terns are the smallest members of the tern family and feed primarily on small fish. They are generally considered seabirds, but several species are also found along rivers, lakes or other wetlands. They nest along more than 2,800 miles of river channel habitat across the Great Plains and the Lower Mississippi Valley and winter in the Caribbean and South America.

Tern colonies occur in Arkansas, Colorado, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Mississippi, Missouri, Montana, Nebraska, New Mexico, North Dakota, Oklahoma, South Dakota, Tennessee and Texas.

In the late 19th and early 20th centuries, least terns were decimated by harvest for their feathers, which were used for making hats. Their nesting habitats were also flooded or degraded by dams and other forms of large river channel engineering during the mid-20th century. Due to the impact of these threats, the bird was listed as endangered under the ESA in 1985 as a distinct population segment.

The ESA requires the agency to implement a post-delisting monitoring plan for the tern for a minimum of five years after delisting to ensure that it remains stable. The plan will include a commitment by the Corps to continue monitoring the species as an indicator of healthy river ecosystems. The USFWS said it will publish a notice of availability when the post-delisting monitoring plan becomes available.