By Kate Crowley
By the time you read this they may have already passed further south, but Oh, I hope you looked up and saw the Common Nighthawks flying overhead this past week. You may have seen them and thought you were seeing gulls, but their sharply pointed wings and erratic flight patterns are unique. We saw the first flocks as we were driving around Bay Lake. I looked up and saw large flocks sweeping over the trees, probably hunting on the wing, which is one reason why their name includes ‘hawk’ in it. This particular type of hunting and eating insects is actually called ‘hawking’. It was mid-afternoon, not night when we saw the flocks, but I was first introduced to these birds when I was growing up in Minneapolis. I didn’t have a name for them at that time, but on warm summer nights when we would be playing kick-the-can out at the street corner, they would be a constant presence around the street lamps, diving down and sweeping upward and making a nasally ‘peent’ call. Today that memory resides in my mind along with all the other perfect images of balmy summer evenings.
Common Nighthawks belong to the Family Caprimulgidae, which includes Whip-poor-wills. A common feature in members of this Family are unusually large mouths that they open wide while flying fast (12 + mph) at dusk through clouds of insects. In this way they scoop up beetles, flying ants, caddis flies, bees, mosquitoes, wasps, and any other flying insect they encounter. Like a living vacuum cleaner, the bugs go straight to the back of the mouth and down the throat where they meet their end in the digestive juices of the stomach. The beak is actually quite small, for the size of the bird’s gape. Because of this large gaping mouth, they were in days of old referred to as “goatsuckers." Seen flying over herds of sheep or goats, people believed that they actually suckled goats.
Nighthawk plumage is gray, white, buff and black and is patterned in such a way that they are nearly perfectly camouflaged for nesting on gravel bars, forest clearings (from burns or logging) coastal sand dunes, and other patches of bare ground or sparsely vegetated grasslands. In urban areas they have often used flat, gravel topped roofs. They have large eyes and short necks which make their head look prominent. Bright white patches on both sides of the wing, near the bend are easy to pick out in flight.
DNA tests show that nighthawks are closely related to owls, and share many morphological structures as well as plumage – like rictal bristles around their beaks. Unlike the owls, the nighthawk has flat feet that are among the smallest and weakest, relative to its size, in the bird world. The claws are blunt and flattened and help the bird balance on flat surfaces, but are of no use for catching prey or defending themselves against predators. As ground nesters they are easy prey for feral and domestic cats, snakes, coyotes, fox, raccoons, ravens, and jays. Their cryptic coloration is their only real means of defense, although their erratic flight patterns made them more difficult for people to shoot when that was still allowed. If active during the day they may become prey for falcons and the accipters, which hunt birds smaller than themselves.
I wish I had been around on August 26, 1990, when 43,690 Nighthawks were counted in a two-and-a-half-hour period flying just north of Duluth. It is much more common to see several dozen individuals soaring in the sky. That’s what I continued to see last week. Hundreds were reported flying over Brighton Beach in Duluth last Saturday evening.
Like so many other migratory birds, Common Nighthawks are threatened with habitat loss, collisions with communication towers, and pesticide residues from mosquito control programs. Nighthawks are dependent upon emergent aquatic insects, so the pesticides are certainly responsible for reducing the birds’ prey base.
I will keep looking upward for the last of these graceful, aerial specialists. They are just one of many species of birds that are beginning that long and treacherous journey to South America where the bugs will flourish through our dark winter months.