The Common Nighthawk has disappeared as a
breeding bird from many areas of southern Ontario. It is listed as
Threatened by the Committee on the Status of Endangered Wildlife in
Canada (COSEWIC). The Carden Alvar, however, remains an ideal
location to hear and see the spectacular territorial booming dives
of the nighthawk.
IDENTIFICATION: The Common Nighthawk shows
a conspicuous white wing patch in flight. When perched, its wingtips
extending to or past the tail tip distinguish it from the Eastern
Whip-poor-will, whose wings fall well short of the tail tip. The
nighthawk has short hair-like rictal bristles (barely visible) on
sides of the mouth, further separating it from the whip-poor-will,
which has long bushy bristles.
VOICE: The flight call, heard mainly on
the breeding grounds is a nasal peent given by both sexes, repeated
every three seconds for long periods. Calling peaks 30-45 minutes
after sunset. Caution: The ground call of the American Woodcock, a
nasal brizst, is sometimes confused with the nighthawk’s call.
Suspect a woodcock if you hear a nighthawk before mid-May.
HABITS: Despite its name, the nighthawk is
usually not active at night. It prefers the twilight (crepuscular)
being most active at dusk and dawn, and is sometimes active during
the day. In August, small migrating flocks are seen in late
afternoon and evening.
HABITAT: The Carden Alvar has ideal
nesting habitat for nighthawks, especially the open areas with bare
ground and alvar pavement.
VIEWING TIP: A warm summer evening on the
Carden Alvar watching nighthawks perform their thunderous booming
dives is an experience like no other. The booming is made by air
rushing through the male’s primaries as it pulls out of a steep
dive. Dives average one per minute. Wylie Road between the viewing
blind and Sedge Wren Marsh is a reliable spot to hear and see
ACKNOWLEDGMENTS: I thank Michel Gosselin
for proofing and Jean Iron for the photos.