Avimor resident Shon Parks and his son Ian observed a Common Nighthawk last night. They were up on one of the hills when they saw it. They report that they were close enough to hear the sound of the air through its wings.
This is the Cool Fact from All About Birds about the sound:
The male Common Nighthawk has a dramatic booming display used during the breeding season. He flies around at a moderate height, then dives straight toward the ground. Somewhere just about two meters from the ground he turns upward. At the bottom of the dive he flexes his wings downward, and the air rushing through his wingtips makes a deep booming sound. The dives are directed at females, young nighthawks, intruders, and even people.
This is the first official record of the Common Nighthawk on Avimor's life list. The long wings with the prominent white patch on the underside of the wing make this bird easy to identify. They are usually seen at dawn or dusk. If you are lucky, you might find one nesting or resting on the ground, on a branch perched parallel, on a power line, or a post. In spite of its name, it is not a hawk at all.