Chimney Swift Communal Roost

I saw on Facebook this morning that the Baltimore Bird Club was sponsoring an evening field trip to Baltimore to observe a known chimney swift communal roost.


I’ve never observed a communal roost, and based on Wednesday reconnaissance performed by the Bird Club, the likelihood for this phenomenon happening was high.


We arrived to the Hampden Bookbindary at 3100 Elm Street, Baltimore, MD 21211 at about 6:40 PM, and others were arriving too.  We walked around to get our orientation and found our vantage point.  Occasional chimney swift were flying overhead and near the chimney roost site.


This is a photo of the building and the chimney, and you can see the swifts beginning to congregate . . .


. . . birders began to congregate too!  By 7:00 PM it was dusk and the group grew from about 20 to 60 onlookers.

At about 7:15 all of the birds began flying in tight circles and dropping into the chimney.  It was at this point that I began filming the activity, and it took thousands of birds all of 4:49 minutes to descend into the chimney for the evening.  Absolutely amazing!



Chimney Swift (Chaetura pelagica) breed throughout the northeast United States and winter in South America.  In September they stage in communal roosts, feed heavily and begin thinking about migration, to ensure a plentiful source of insects to feed upon.  The average life span of a chimney swift is 4.6 years, and both sexes look nearly identical.  Nearly the entire life of this bird is spent airborne, feeding and drinking on-the-wing.  They have a characteristic choppy, stiff, fixed wing beat, and can not perch like most birds.  Instead, when they land, they must cling to vertical structure.  In late summer, thousands of individuals roost in chimneys, gathering in spectacular flocks overhead at dusk, and this is exactly what we observed this evening.

To finish off the evening, Michelle, Tom, Jennifer and I went to Birroteca for a few beers and pizza.