Herndon — Visitors to Runnymede Park over the past few weeks might have noticed a new feature in the median of the parking lot, a freestanding chimney. The structure was recently installed by the Friends of Runnymede Park with hopes that it will attract the chimney swift, a small, high-energy bird that spends the warm seasons in the area.

“Every fall my husband and I go into Arlington and watch these huge clouds of chimney swifts swirl around and go into a chimney there,” said Carol Hadlock, president of the Friends of Runnymede Park. “But there aren’t many around here. They don’t seem to use a chimney that’s in Fairfax anymore, and they used to go to Herndon Middle School, but not anymore. These birds don’t have anywhere to go at night.”

The chimney swift is a bird with a cigar shaped body, scythe-shaped wings and legs too small to support their body, so the birds must rest by hanging upside down.

“Their feet don’t allow them to perch, instead they cling to a vertical surface,” Hadlock said. “The inner chamber of the chimney is made of T1-11 plywood, which has a rough surface that they can grasp.”

HISTORICALLY the birds have nested in hollow trees, but as forests declined in the area, they started moving into chimneys.

“In the mid-90s, people started capping their chimneys, and new construction techniques used a slippery surface on their interiors, as well as metal flues,” Hadlock said. “Since the mid-90s, the population of chimney swifts in the area has declined by 55 percent.”

The chimney was built by a Friends of Runnymede board member who is a carpenter, using plans published by the Driftwood Wildlife Association.

It has a concrete base with legs to support the structure, which stands 14 feet tall. It has Styrofoam insulation to keep it from overheating, as well as a metal guard to keep snakes out.

“Each chimney will host one pair of birds that will build a nest, and others might periodically roost there,” Hadlock said. “In the fall, hopefully we’ll start to see, and eventually we’ll start to see them gather around the chimney and form a funnel, like a tornado, and they’ll all go through the chimney. It’s quite a sight.”

She said that the chimney was likely installed too late in the seasons for the birds to get a sense of it this year. They will migrate to South America over the winter, and Hadlock says she hopes they’ll start to investigate the new structure upon returning in the spring.

In addition to the spectacle, the birds offer other benefits to the park. Chimney swifts consume 30 percent of their weight every day.

“Runnymede Park is home to over 450 native plants, and as a result, there are a lot of insects, primarily mosquitoes,” said Dave Swan, a board member of the Friends of Runnymede Park, when pitching the idea to the Town of Herndon’s Architectural Review Board earlier this year. “The biggest predators for those insects are chimney swifts.”

The Friends of Runnymede had to receive approval from the town, who owns the park property.

Raymond Ocel, a planning and zoning administrator with the town, said the location near the parking lot is chosen due to its proximity to the fields, where the birds will hunt for food during the day.

THE FRIENDS OF RUNNYMEDE PARK will host an official ribbon cutting ceremony during the Oct. 6 NatureFest. It will take place at