Now is the time that Chimney Swifts start forming in communal gatherings before migrating south for the winter. This gives us an excellent opportunity to gauge their population numbers and try to assess trends for this species.
Unfortunately, according to the latest North American Breeding Bird Survey, the Chimney Swift population has declined by 72% in the past 50 years. By continuing to monitor these populations, we hope to learn more about how they are doing and identify important roost sites so we can find ways to help protect them. Because Chimney Swifts congregate in communal roosts before migrating in late summer/fall, it’s relatively easy to count them.
How to count swifts
1. Look for tall brick chimneys that are uncapped.
2. Pick one or more nights to monitor from early August in northern Wisconsin through mid- to late September in southern Wisconsin.
3. Observe the roost starting about 20 minutes before sunset until 10 minutes after the last swift enters the chimney. Please stay in one location, even if you do not see swifts right away. They may come to your site later, and you do not want to miss them. To be sure, stay 30 minutes after sunset to know if it was active or not. If you have zero swifts in your chimney, please record this. This is still valuable information.
4. Count (or estimate) the number of swifts as they enter the chimney. It’s useful to count in groups of five or ten when they enter quickly in large numbers.
When you do the count, you can help researchers access and utilize your data by entering the data on eBird. When prompted for a location, map your roost site to an exact address or point. After you enter the number of Chimney Swifts, please use the hash tag #swiftwi in the Chimney Swift details section. This will help us greatly in accessing the data.
If you want to go a step further, please add the following information in the Chimney Swift details section in this exact order, with semicolons separating the data: #swiftwi; the type of building (residence, school, church, business, hospital, apartment, swift tower/structure, etc.); the condition of the chimney (in good shape; in need of repair); any other notes (for example: #swiftwi; residence; chimney in need of repair; any other notes).
How to identify swifts
Chimney Swifts have slender bodies, with long, narrow, curved wings and short, tapered tails. (They look like a flying cigar.) They fly rapidly, with nearly constant wing beats, often twisting from side to side and banking erratically. Often, they give a distinctive high chittering call while in flight. They are the only bird that will roost in a chimney, dropping inside at dusk and emerging the next morning.