This is the second year now that I have been helping Shannon Kearney-McGee, of the Connecticut State Department of Energy and Environmental Protection (click the link to access information on Chimney Swifts) to monitor, count, Chimney Swifts roosting in the chimney at the Mitchell School here in Woodbury, CT.
Most birding books describe Chimney Swifts as lookign like flying cigars, and after watchign them for two years now, it's a pretty good description. Watching them flying and maneuvering to catch insects, as well as circling around the chimney, reminds me of World War II fighter planes - like the P-51 Mustang. 
Last night, I counted, in 5-minute intervals, 144 Chimney Swifts going into the chimney to roost for the night - 98 in one 5-minute interval! The swifts begin to circle the chimney about 15 minutes before sunset and increase in numbers closer to sunset. Then about an half hour after sunset, they start to "fall" into the chimney for the night. To see a video I made last year of the swifts, click here.
Besides the swifts, I also saw a Common Nighthawk - it was showing the same erratic behavior of the swifts but was much larger. So I grabbed my binoculars and as it flew by I was able to see the swept-back wings and the white bars in the middle of the wings - Nighthawk for sure!
DATA: 7:46-8:46pm; 67F; cloudy; slight breeze
