Slip Sliding Away By Scott Kirkwood
National parks in the East provide ideal habitat for cerulean warblers, but land-use decisions outside the parks—and outside the country—pose a serious challenge.
As night falls on thousands of classical musical lovers spread across the lawn of the Blossom Music Center—the summer home of the Cleveland Symphony Orchestra—a few concertgoers are fortunate enough to hear the call of the cerulean warbler in between movements. The popular amphitheater is nestled in the middle of prime forest habitat within the confines of Cuyahoga National Park. But like one-third of the 33,000 acres within the park's legal boundary, it's private land not actually owned and operated by the Park Service. That poses a challenge for those trying to preserve habitat for a species making a rapid decline. Fortunately, classical music fans appreciate the natural setting, and the symphony does all it can to manage the property consistent with Park Service recommendations. But not everyone is so willing to go along with the plan.
Ceruleans and many other migratory birds divide their time between two continents, spending their summers in the United States and the remainder of the year in the South American mountains of Bolivia, Columbia, Peru, and Venezuela. Increased development in those nations, including coffee plantations, is fragmenting prime cerulean habitat. Meanwhile, a few hundred miles south of Cuyahoga National Park, coal mining just outside of the Big South Fork National River and Recreation Area is destroying forests and waterways in the region, home to the largest concentration of cerulean warblers on the continent.
There was a time when cerulean warblers were so plentiful that birders wouldn't have taken much notice of them flitting through the nation's eastern forests. But development and habitat fragmentation in recent decades have driven the species' numbers down more than 70 percent since the 1960s. That staggering statistic and the bird's penchant for neck-craning locales atop the forest's canopy have made it a birder's holy grail.
In fact, biologists aren't even sure where to look for them anymore. Volunteers at Cuyahoga helped the park conduct a sampling in 2001, yielding enough detail to predict the presence and absence of certain species, including the cerulean warbler. Park employees now use that knowledge when pointing birders toward prime habitat, and they consider several factors when deciding where to remove trees for new campgrounds, trails, and parking lots.
One thing that's clear is the bird's preference for mature deciduous forests throughout the Appalachians, from southeast Pennsylvania to West Virginia, eastern Kentucky and Tennessee's Cumberland Mountains. More than 70 percent of the breeding cerulean warblers live in the Cumberland Mountains, which has seen a resurgence in mining in recent years.
According to Ken Rosenberg, lead researcher for the Cerulean Atlas Project, the most serious threat, by far, within the breeding range of the cerulean warbler is the practice of mountaintop removal mining. As much as 10 to 20 percent of the known cerulean population may be directly eliminated by proposed and permitted mountaintop mining alone. The impact has been felt by mussels, several threatened fish species, and six other migratory bird species in addition to the cerulean warbler. Voids left by underground mines are often flooded by inflows of surface water or groundwater, then collapse, releasing contaminated water into the watershed. The results have devastated water quality and biodiversity in the Big South Fork National River and Recreation Area in Kentucky and Tennessee. Surface mining, another popular method of extraction, destroys the steep slopes and mountain ridges favored by the birds and fragments large tracts of land that make up its ideal habitat. Once the damage is done, it's nearly impossible to reforest the land in any reasonable amount of time.
NPCA, Audubon, and the Southern Environmental Law Center are petitioning the Office of Surface Mining to bring an end to the destruction and protect the surface waters of the Big South Fork. Several years ago, more than 20 advocacy organizations petitioned the Fish and Wildlife Service to list the cerulean warbler as threatened under the Endangered Species Act, and a ruling is expected in the coming months. Both of those proceedings certainly offer some promise for the cerulean warbler, but the question is: Will the remedy come soon enough?
Scott Kirkwood is senior editor for National Parks magazine.
