A high-rise for birds is being built on Sparkle Island in Allentown's Muhlenberg Lake.
City officials expect the 20-foot-tall tower will become the home of mosquito-eating chimney swifts.
"Hopefully, it will become occupied next spring, and the colony could grow to several hundred birds,” said John Mikowychok, director of the city’s parks and recreation department.
The project is being done by the city, the Lehigh Valley Chapter of the National Audubon Society and the Friends of the Allentown Parks.
Chimney swifts, described as "sleek, sooty-gray birds with elongated bodies," cling to the insides of large, hollowed-out trees, explained city officials. In North America’s urban areas, they have adapted to living in chimneys during the summer.
They don’t conflict with a chimney’s traditional use, because they migrate each fall to western South America for the winter. However, capping chimneys with squirrel guards or closing them in favor of other home-heating methods has greatly reduced their habitat.
“The tower mimics a chimney,” explained Mikowychok.
“Our volunteers are building it to be very effective – it drafts at the bottom, for air circulation. It has insulation panels to prevent the chimney from getting too hot in late spring, which could threaten the eggs or young chicks. And, it will have concrete siding, weather-proof capping, and cedar corners to protect it from the elements.”
Volunteers began construction of the tower in Allentown on Sept. 28, National Public Lands Day. The Friends of Allentown Parks and students from nearby colleges provided labor to also plant dozens of native trees, shrubs and grasses on the island. Area business provided materials free or near cost. The tower should be completed by the end of October.
The project is seen as desirable by bird enthusiasts and offers substantive environmental benefits.
Said Mikowychok: “With the recent decline of an estimated 90 percent of Pennsylvania’s bat population due to white-nosed fungus, the ecology of Pennsylvania’s wetlands and ponds is changing, albeit slightly.
"A bat will eat thousands of insects, including mosquitoes, each summer evening. With the collapse of Pennsylvania’s bat population, mosquito populations are likely on the rise.
"Since a large flock of chimney swifts provides a similar mosquito control as bats, creating habitat for them provides another solution to controlling mosquitoes, particularly near still-water ponds like Muhlenberg Lake.”
Mayor Ed Pawlowski lauded the groups’ efforts: “This is a prime example of the synergy between environmental groups, park users and Friends, and our parks and recreation staff in using new technologies and creative ideas to solve environmental problems.”
The idea of a chimney swift tower for a public park in Allentown was first conceived by Scott Burnet, habitat committee chairman for the Audubon Society’s local group.
“I had constructed one on the side of my garage, as a means of providing roosting shelter en masse for the birds,” he said in a news release. "In reality, it’s the equivalent of the old Purple Martin houses, only for Chimney Swifts.”
Burnet had borrowed a book from Peter Saenger, curator of the Acopian Ornithology Center at Muhlenberg College and president of the local Audubon Chapter, entitled ‘Chimney Swift Towers: New Habitat for America’s Mysterious Birds,’ by Paul and Georgeanna Kyle. In it, he learned of the details for fabricating the bird chimney without an adjoining house.