In North America’s spring, a bubbly song burbles up from some grassy meadows, the song of the breeding male bobolink. It is a “bubbling, jangling warble with short notes on widely different pitches; ending faster, fuller, higher,” says the Sibley Guide to Birds.

Bobolinks fly up to 12,500 miles round trip to and from South America every year. With a white back, black underparts and a straw-colored head, breeding males are unusual. Some say they seem to be wearing a tuxedo backwards.

Bobolinks are one of three grassland birds that have been confirmed in a 50-acre closed part of Fairfax County’s I-95/Lorton landfill. The other two species are eastern meadowlarks and grasshopper sparrows. These are grassland specialists, birds not typically seen in other parts of Northern Virginia where meadows and grasslands are scarce. This part of the landfill is in effect a grassland. 

“More than half of bird species that depend on grasslands for breeding habitat are in steep decline,” concluded the recent State of the Birds report. Nationally, the U.S. Fish and Wildlife Service reports that grassland birds have dropped by 53 percent.  Most experts point to habitat loss as a major factor.

Grasslands Are Rare

Of the United States’ historical 550 million acres of temperate grasslands, 62 percent are gone. In April, the Cornell Lab of Ornithology found that the country is losing 2.5 million acres of grasslands a year.

Less Mowing

Some birds, like bobolinks, turkeys and pheasants, make nests, lay eggs and raise their young on the ground. At the urging of the Northern Virginia Bird Alliance (NVBA), in February, the Board of Supervisors directed the county staff to develop a plan to avoid mowing parts of the landfill property during grassland birds’ nesting season, generally April 1 and mid-July, and to identify a “no-mow” area. County staff then designated an area and significantly reduced mowing there.

Blair Evancho conducted a bird survey between Aug. 22 and Oct. 17, 2024, and issued a report on March 18.  Evancho documented 29 bird species in the study area. “The most recorded birds were grasshopper sparrow, savannah sparrow, American kestrel and eastern meadowlark, all of which are experiencing population declines,” says the county’s website. 

County officials announced that they will continue to limit landfill mowing during the nesting season, raise the mower blades to a height of eight inches and continue monitoring birds at the site. While some mowing is needed to access methane gas wells and for worker safety, the revised mowing schedule “should give grassland birds a better chance to thrive,” said Evancho.

Mount Vernon Supervisor Dan Storck, who initiated the effort with the Board of Supervisors, said, “The I-95 landfill is the largest and most important grassland in eastern Fairfax County. I was very pleased to work with Mount Vernon residents to bring a Board matter, which was very strongly supported by County staff, directing development of a plan to protect nesting grassland birds on the landfill. This action positions the County to be a leader in grassland management on landfills.”

The county’s report concluded, “Declining grassland bird populations are a threat to healthy and diverse grassland ecosystems. On a national scale, grasslands provide essential and significant habitats for mammals, pollinators, reptiles and other wildlife of commercial, recreational, scientific, aesthetic and cultural value. Healthy grassland ecosystems provide services such as carbon sequestration, carbon storage, drought and flood resilience, water filtration and water storage. 

“If conservation of native biodiversity is not enough of a motivator, these factors should provide motivation to be invested in efforts to reverse the decline of North American grassland birds. 

“Here on the East Coast, the vast majority of our natural grassland ecosystems have been erased leaving agricultural land and areas with enough open space and tall grass to attract grassland birds, such as I-95 Landfill Complex, as the only hope for grassland birds in this region to find suitable habitats. Implementing efforts to encourage the presence and health of grassland birds wherever they are found through monitoring and grassland bird-friendly land use is the best way to do our part in the growing effort to save these species from decline.”

Libby Lyons, President of NVBA, commended the county and said, “Grassland habitats are under threat across the country, so this work will not only help our local birds, but can provide bird-friendly practices for other landfills. NVBA has worked with Fairfax for several years, for example, putting up kestrel nesting boxes there.  NVBA volunteers and landfill staff will extend last year's study on how the new mowing regime impacts birds during their spring breeding season.”

Information

https://www.fairfaxcounty.gov/publicworks/recycling-trash/i-95-grassland-birds