Common Nighthawk, Chordeiles minor

Wednesday, July 15, 2009

Nature Notes
by Bob Thomas

One of my favorite sounds of early evening in summer is the flight call of the common nighthawk (Chordeiles minor), often called the bullbat in reference to its bat-like erratic wing flapping and twisting flight. I see and hear them each summer evening flying through the lights on Loyola's Marquette Hall. Their call is "speek-speek," repeated at short intervals.

This species has a slightly forked tail and long, narrow wings. Aside from its characteristic shape and flight pattern, common nighthawks have obvious white bars across the wings. They also have large eyes.

They are migratory, arriving in coastal Louisiana each April and leaving in September.

Common nighthawks are typically crepuscular, meaning that they hunt at dawn (aurorall, matutinal, or matinal) and dusk (vespertine or vesperal), but they are more noticeable at dusk. Although they are often seen feeding in lighted areas at night, they typically rest in the evenings, usually sitting on objects (rarely on the ground), and they love flat roof tops.

During their courtship displays, the males dive straight toward the ground and turn back up about six feet off the ground. The wind blowing through their stiffly held wings creates a booming sound.

They don't construct nests, but simply lay their eggs on the ground. Both sexes incubate the two eggs, but the females give the offspring more attention. The eggs hatch in about two weeks, and the young (fledglings) fly three weeks after hatching.

Common nighthawks are members of the Caprimulgiformes, an order of birds whose members typically have extremely large mouths that are surrounded by rectal bristles, hair-like modified feathers that help direct prey into their mouths. They feed on insects which they catch in their large open mouths. Specimens have been found with as many as 500 mosquitoes in their stomachs, and 2100 flying ants. I hope they like Formosan termites!

Also published in Delta Journal, The Times Picayune, September 30, 2007.

                                  

Common nighthawk (Chordeiles minor)                                   Common nighthawk in flight.
resting on a wire. All photos taken in                                       Photo by Thomas Finnie.
Calcasieu Parish, Louisiana.
Photo by Thomas Finnie.

                                 

A pair of common nighthawks flying                                       Common nighthawks continuing their
synchronously.                                                                      joy of flight!
Photo by Thomas Finnie.                                                     Photo by Thomas Finnie.