The swirling hurricane of thousands of tiny black birds plunging into the Masonic Temple chimney at the gateway to the southside of Bethlehem is certainly a beautiful and haunting sight. It is also a reminder of the ways that nature has adapted to the structures we build for our own human purposes. These tiny dark birds swirling in the evening sky are chimney swifts. They can be seen in such vast numbers in Bethlehem during their migrations in April and October. The swifts are important to the ecologies of Bethlehem and the surrounding areas, and are fascinating for their unique adaptations which make the chimney their home. Sharing their incredible story is part of an initiative for Bethlehem to save our swifts and the habitats in which they thrive.
As of February 2nd, Chimney Swifts have been adopted as the bird of Bethlehem. Yet recognizing them as beautiful creatures that live alongside us isn’t enough. Their home was in danger. The chimney attached to the former Masonic Temple off 378 was in danger of being torn down earlier this year. This one chimney is home to an estimated thousands of migrating chimney swifts each year. Relocating the chimney wasn’t an option, as the birds have a specific knowledge of the chimney’s location, and relocating the chimney wouldn’t necessarily result in the birds finding their home again. Yet local bird lovers and developer John Noble were determined to save the chimney for the swifts! A team from Bethlehem that includes Jennie Gilrain, members of the Audubon Society, South Side Iniative, and others worked with the developer to explore ways to save this chimney and ultimately found a way to preserve the chimney even as the Temple was demolished. Today, the swifts’ home is all that is left on the site.
There is a lot to love about these little birds. They are five to six inches long, but they fly so high above our buildings and heads that they often only register as tiny specks in the sky. They are not perching birds—they spend most of their time aloft and are actually physically incapable of perching on a branch or even standing on the ground like most birds. Instead, chimney swifts have evolved very long and sharp claws that allow them to cling to vertical surfaces. Before the colonization of the Americas, these little birds roosted in hollowed out trees. Due to all the deforestation that accompanied the colonization of North America, their traditional habitat was much scarcer, so they adapted and started nesting in chimneys—incredibly abundant architectural features in early American architecture. But as Americans started capping chimneys, chimneys started becoming less available to the swifts.
Aside from valuing chimney swifts simply in terms of ecological diversity, these birds are very helpful little creatures. An individual swift eats up to 12,000 flying insects—like beetles and mosquitoes—every day, keeping bug populations under control and reducing the ever increasing risk of vector-born diseases that humans face. The chimney swift also has a very sticky, glue-like saliva, which they use to attach twigs and branches to the sides of chimneys as nests. They range widely in their migration, living in the Eastern half of the United States during the warmer months, and flying 3500 miles to Brazil, Peru, and the Northwestern quadrant of South America during our winter months. They are very fastidious and clean. Many homeowners unsuspectingly host chimney swifts for years! Finally, not much is known about the relationships between chimney swifts. While mating pairs are monogamous while nesting and raising their young, chimney swifts have been seen to host a third bird during their nesting phase. These mysteries are also part of the joy of coming to understand these quirky birds.
The chimney swift as a species has seen a 72% decline over the last 50 years, due in part to habitat loss like chimney capping (or making chimneys out of steel, which they cannot cling to), but also due to decreasing populations of their favorite food, beetles, thanks to widespread pesticide use. Without chimneys to roost in, these birds are in danger of predators and harsh weather. Saving the chimney at the site of the old Masonic temple is one way John Noble and the residents of Bethlehem have helped our chimney swifts thrive.
The Lehigh Valley Audubon society also has been helping chimney swifts thrive, creating chimney swift towers on public land for the birds to nest in. Swifts tend to nest singularly and migrate in groups, so the Masonic Temple chimney is a key way-station, a gathering place, on their migratory path, but the Audubon’s nesting towers are just as important. Part of the Save Our Swifts initiative (which includes partners such as Bethlehem Area Public Library and Bethlehem’s Environmental Advisory Council in addition to the organizations listed above) is raising money to make the restoration and incorporation of the old Masonic Temple chimney into the new development feasible. Another part is simply to do what ornithology (or the study of birds) has always done: incorporate the science and observations and passion of amateurs to learn more about the ways birds live in our world. And ultimately the mission of the initiative is to identify ways that people and developers can support swift habitat in our community, building a city that is truly for the birds and ourselves, through cooperation between activists and developers in other contexts.
While we may have helped save the swifts’ chimney, the birds in turn have taught us a lot about what it looks like to adapt plans to consider them, too.
Hannah is a grad student in English at Lehigh University and is a regular contributor to The SouthSider, which focuses on SouthSide Bethlehem’s community and culture. After she completes her M.A., Hannah hopes to continue teaching about environmental imagination and anti-racist practices in the outdoors industry.