Thanks to Maddie for sending:
“I live in Lanier Heights and for the past few weeks, we’ve noticed birds (not bats, like some initially thought) start to congregate and circle around the building around sundown. This dance starts with a few dozen and in 20 minutes there are thousands flying in circles in one direction then quickly switching course, moving around slightly until they abruptly start flying into the chimney of the building next door.
Some of the residents of my building have become regulars and experts. We don’t think it’s been happening for more than a month and figure it won’t last forever, but I’m curious if anyone knows more about chimney swifts around DC. Are there other chimneys? Are they migrating south? Were they all in another chimney before? Where are they coming from?
None of us have seen them fly out in the morning but my guess is they disperse throughout the city.”