There are three types of nighthawks seen in North America; the Common Nighthawk, Lesser Nighthawk and the Antillean Nighthawk. The Common Nighthawk is the most common among this group and is seen throughout North America. The Lesser Nighthawk is found in the southwestern states and its plumage is more brownish in colour than that of the Common Nighthawk. The Antillean Nighthawk covers the smallest range and is only seen in the Florida Keys and is much more common in the Caribbean islands.
Nighthawks are insect eaters and are usually seen in the evening and early morning skies when the insects are more active. With their long wings, these birds put on an aerobatic display like no other bird can. At one time these birds were far more common in towns and cities but this has changed over the last thirty years or so for various reasons.
ABA - American Birding Association This site represents an organization that maintains official records of all birds species that have been proven to have been seen inside the perimeters of the North American Continent and the surrounding bodies of water. Regular revised versions are posted to keep the bird list current at all times. This is the list used by all serious birders over their lifetime. You may be aware of the movie called the "Big Year". It was with this list that all the competing birders used in an attempt to set a new record as to how many bird species that could be seen by an individual birder in one calendar year.