Conserving Chimney Swifts in the Wissahickon Valley
Chimney swifts (Chaetura pelagica) are one of the most distinctive bird species in North America, easily identified by their stocky silhouettes, chattering voices, and impressive aerial acrobatics. They are an integral part of a healthy environment, and some of nature’s most effective pest controllers; one bird can devour more than 1,000 mosquitoes in a single day. This helps greatly reduce the need for pesticide use. In the last few decades, however, chimney swift populations in the United States have dropped more than 50 percent – Canadian populations by 90 percent. This alarming decline is largely due to habitat loss.
Unlike many birds, chimney swifts are incapable of perching and spend almost their entire lives on the wing – this means they also have very specific habitat needs. In the past, hollow trees served as nesting and roosting sites, but with industrialization – and an increase in the removal of dead trees – they adapted to using human-made structures instead, thus earning their name (the photo on the right is of an active nest inside a chimney).
But, as alternative heating systems replace existing chimneys, as new chimneys are constructed in a way that makes them unusable to swifts, and as old remaining chimneys are capped, swifts have fewer and fewer places to go.
But there is good news! Habitat for these remarkable birds can be created in the form of artificial chimneys or ‘towers,’ which serve as essential nesting and roosting sites. Swifts occupy these towers during the summer breeding season and roost in them during fall migration – sometimes by the thousands. In July of 2017, WVWA finished the construction of our first tower at Crossways Preserve and we will be monitoring its use in the spring, summer, and fall throughout the coming years. We hope to build several more towers at other sites with appropriate habitat, and to continue our efforts to help further the conservation of this special species in the Wissahickon Valley.
Building a Chimney Swift Tower
Below are some photos of construction and installation. First, the bottom tower section was built and secured in the ground with a concrete footing. The remaining 4-foot sections were then built, stacked and secured on top of one another. Insulation was added on each of the tower's sides before siding - this helps keep the tower warm in the fall when birds are roosting overnight during migration, and keeps it cool in the summer when they are nesting. Finally, siding was added to keep out water and wind, and the tower's cap, which mimics the opening of a typical chimney, was secured on top.
More reliant on man-made structures than perhaps any other birds, chimney swift populations are also more easily helped by our actions than many. If you have a chimney, be sure to have it cleaned in March, prior to their breeding season (from May to August). If possible, leave it uncapped until the winter. And of course, help us spread the word about this amazing species and their need for conservation, and support WVWA in our efforts!
If you’re interested in learning more about chimney swift conservation and how you can help collect valuable data, contact our Stewardship Coordinator, Margaret Rohde, at firstname.lastname@example.org.