For the Birds Radio Program: Nighthawk migration

Original Air Date: Sept. 3, 1990

Nighthawks with the mantra, “Bolivia or Bust!” are passing through right now. Laura talks about how she cares for injured ones.

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Labor Day evening is a time to look skyward as the last of the season’s nighthawks silently wing their way toward South America. They never seem to hurry; they dart and flutter this way and that to snap up a myriad of insects, from giant dragonflies to bugs too tiny for human eyes to detect, fueling their 2 1/2 ounce frame even as they travel. Considering the many mosquitoes they eat, they apparently subsist, at least indirectly, on human blood.

In spite of the atmosphere’s entomological distractions, they make steady progress southward. If nighthawks wore T-shirts, they’d probably read “Bolivia or Bust.” Few will be satisfied with Central America, and many of our northland nighthawks will journey all the way down to Argentina.

Nighthawks eat flying insects on the wing. They zip through the evening sky at about 20 miles per hour with their capacious mouths hanging open, and bugs just pour in. There’s no need to swallow—at that speed the insects automatically go down. I’ve cared for at least ten different nighthawks, and not one has ever figured out how to eat when it’s grounded—each must be hand fed at least a dozen times a day. And it takes days or even weeks of patient throat-rubbing to teach adult nighthawks how to swallow. No matter how hungry they are, or how eagerly they run to me for their meals, they simply can’t get the food into their own mouths, and unless I stick the food deep into their throats, they just can’t get it down.

The nighthawk’s absolute dependence on flying insects is why it migrates so far—it must be guaranteed a constant food supply for the winter. By avoiding Central America, where the majority of North America’s insect-eaters winter, the nighthawk also avoids much of the competition.

Nighthawks spend their days resting on a horizontal perch, quietly observing the world. I never keep an injured nighthawk in a box or cage—I just set it on the windowsill in my office. It sometimes faces the morning or evening sun, sometimes follows the movements of neighborhood chickadees, sometimes just watches me work. Its somber gray plumage, quiet dignity, and incongruously comical, short-legged waddle make it the Charlie Chaplin of the bird world.

Last Sunday I set a nighthawk free. She’d bruised her wing crashing into a power line six days before, and her beak was bent crooked. All Sunday she sat calmly at my side while I researched important facts about her species, like that one nighthawk had 3,332 feathers, and that French Creoles in Louisiana call them “crapau volans,” or “flying toads.” She watched me but listened to her inner clock, which kept whispering that this was the day.

About six o’clock, nighthawks started streaming over, and suddenly she flapped her wings, anxious not to be left behind. So I brought her outside. She patiently posed for a few photos and then raised her wings and was of. She knew what she was getting into—she was an adult who’d made the journey back and forth at least once before. That same evening, Mike Hendrickson was counting 43,690 nighthawks in 2 1/2 hours at the Lakewood Pumping Station just up the shore from Duluth, and I counted more than a thousand in the next half hour, so I knew she’d be in good company. Bolivia will be richer for her presence.