Hi,
Earlier in the week I saw Chimney Swifts in the center of town during the
period around sunset. During one of those times I noted that they were flying
low over a chimney at Vienna Elementary School. I didn't have time to linger
on either evening. But tonight I had time to watch the chimney to find out if
this is a roost site and how many birds are involved. It is being used as a
roost and the number is much bigger than I imagined.
I parked in the library parking lot at Center St. and Maple Ave. around 6:45.
Just a few swifts were overhead. However by 6:55 the number had grown to
dozens.
The first swift may have dropped into the chimney at 6:55 according to my watch
but it may not have entered at all. Sometimes it's hard to tell. Swifts kept
coming from somewhere, as the flock swelled to 500. Around 7:00 they all flew
in a clockwise direction - so cool to observe! A few minutes later they all
flew in the opposite direction. Always they were fairly low, near treetop
level. At 7:04 they definitely began entering the chimney, usually several
w/in a few seconds of each other. The pace picked up and at 7:08 the last bird
entered the chimney. It was fairly dark at this time.
As I walked to my car I noticed a lone swift, perhaps part of the flock, flying
off to the southwest.
I'm glad I got to witness this spectacle, only a mile from my house. The only
negative was that there was no one to share it with. I think that even
non-birders would enjoy a large swift roost. I wonder for how many weeks
they've been using this chimney.
Scott Baron
Vienna, Va.
