The common nighthawk (Chordeiles minor) belongs to a groups of birds known as nightjars which are also reffered to as goatsuckers a name derived from an old wive's tale that they sucked the milk from goats. When I was a kid they were known to us a "bullbats". Mostly active during the early morning and late evening they feed on all sorts of flying insects such as flies, mosquitoes, beetles, grasshoppers, moths, and butterflies. On this day I was fortunate to witness the courtship ritual being performed by a male common nighthawk towards a female. The male began by approaching the female and performing a rocking motion while at the same time puffing out its throat displaying a large white patch. I was able to get a short (grainy) video of this. Afterwards he flew and begin circling over her and then carried out his diving aerial display. He would fly straight up into the blueness of the sky, stall and then plunge headlong like a stone. Moments before it appeared it was going to strike the ground it would arc upwards sharply. This arcing motion causes air to rush though its wing feathers producing a "HOOOOOV" sound. I was unable to record this, but found a sound recording which begins with the "peent" call and is followed by this "HOOOOOV" or "booming" sound. A cool observation to say the least.