Hi Tweets,

One hot and humid Labor Day evening years ago, a girlfriend and I were
watching a ball game at the old Exhibition Stadium in Toronto when a huge
globe of Common Nighthawks Chordeiles minor numbering well over a thousand
birds moved in from the close-by waterfront and settled to hawking insects
attracted by the stadium lights. Discovered that as with many migrant
species, notably raptors, this southbound staging of them at or near Toronto
along the shoreline was an mostly-annual event around Labor Day.

Besides the large number, what was interesting was that the birds retained
this spherical structure as they moved off along the waterfront when the
game was over and the stadium staff turned the lights off, like a single
giant atom of nighthawkium.

It's pretty clear from people's observations a couple of years ago that on
the Pacific Coast migration nighthawks and Black Swift Cypseloides niger
often migrate in southbound association. But I'm not sure if there's an
eastern analogue, with nighthawks migrating southward with Chimney Swift
Chaetura pelagica, though seeing the two species foraging on a summer
evening over Toronto was a commonplace.

Michael Price
Vancouver BC Canada
mprice at mindlink.net