I stopped at the Luther Jackson MS this morning before work.
When I arrived at 6:38 am there was no activity at the chimney (backlit by
clear pre-dawn sky). At 6:47 am Chimney Swifts began exiting the chimney at
an estimated rate of 100-120 birds per minute. This exodus continued at
this pace until 6:55 am when the rate slowed to a trickle. By 6:57 am there
were no additional birds leaving the chimney. Sunrise was at 6:51 am. At
7:01 am I left for work. As this represents approximately 800 to 1000
birds, whereas recent reports estimate at least twice that number entering
in the evening, I'm wondering whether some of the flock was "sleeping in"
and choosing to leave later in the morning.
Their mode of egress contrasts with their "funnel cloud" entrance. The
birds exiting would "bubble up" much like a pot boiling over, with
individual birds popping up in groups and seeming to fall over the sides of
the chimney only to swoop up again after descending 10 or 20 feet.
Dave Larsen
Haymarket
