The air is alive with activity on a summer night in downtown Keene. Above the brick buildings on the Keene State College campus, a pair of bats flit and fly, changing directions as their sonar pings, whipping this way and that. The pair bob off into the distance, and soon after, another winged creature takes their place, cutting a silhouette against the orange-hued clouds of sunset.
The ground is teeming with activity, too; when school’s out, the campus squirrels grow bolder, darting down the main drag. A rabbit even makes an appearance, stopping for a moment to nibble on some white clover and then hopping off. And, there’s some human activity as well – a group of 20-somethings with binoculars and clipboards, eyes trained on the skies.
A high-pitched “peent!” cuts through the night air, and that winged creature suddenly dive-bombs the group of observers. As it reaches the depths of its descent, the air rumbles, displaced, with a low booming sound.
“That was it!” one student shrieks.
The nighthawk continues its peenting, diving and booming, as the group frantically takes down notes.
For centuries, that “peent” has been a familiar call in New Hampshire cities. As the weather heats up, nighthawks return from their southern migration, and that cry rings out as the sun goes down.
“Each May, when I hear it for the first time again after the long winter, it always feels like a special welcoming of summer,” said Brett Amy Thelen of the Harris Center for Conservation Education.
Now, though, that call is heard less and less frequently. New Hampshire’s nighthawk population, which exploded in the 20th century, has been on a sharp decline for the past three decades.
In 1990, nighthawks were found nesting in 16 New Hampshire cities; now, they can only be found in four, including Keene.
Thelen has been on the forefront of Project Nighthawk, a statewide initiative of New Hampshire Audubon, since 2007. The project, headed by the Audubon’s Becky Suomala, observes and record nighthawk nesting activity around the Granite State.
“The species as a whole has declined significantly everywhere,” Suomala said, “and especially in the Northeast.”
During the Industrial Revolution, she explained, the birds thrived in cities, where the gravel roofs of mills and factories proved fertile nesting grounds. But as building owners convert their roofs to PVC or rubber, the nighthawks’ gray, white and black camouflage becomes ineffective, and the surface becomes too hot for a nest. However, that’s not the whole story, she said.
“We don’t know why nighthawks are declining,” Suomala said. “The conversion of stone roofs may explain why they are declining in our cities, but that may not be the reason. There might be pesticides that are being used more heavily on their migration path or their wintering area that may be reducing the amount of insects in those areas.”
Nighthawks are aerial insectivores, and their nesting and migration habits are driven by bug populations.
“These are birds that eat insects on the wing,” Thelen said. “The whole guild of birds which do that are on the decline.”
Nighthawks devour insects like mosquitoes by the bellyful. One study reported that the birds can eat 500 mosquitoes a night, and another reported a single nighthawk’s stomach was found to contain over 2,000 winged ants.
Thelen and her team of volunteers — mostly Keene State College students looking for some summer credits — spend their nights with their eyes — and ears — trained on the skies, searching for any evidence that nighthawks may be nesting nearby.
Recently, they’ve focused their efforts in Keene, where signs of courtship and nesting have been evident. A male nighthawk, Thelen said, will attempt to impress the female with its plaintive “peent” and thunderous boom, soaring and diving all the while.
Thelen said that we can’t know exactly what the female nighthawk sees in that behavior, but that it’s impressive, even to humans.
“I can say what I see in it,” she said. “They’re just incredibly acrobatic fliers so it’s a real thrill to watch. They’re kind of like a rollercoaster — they do these incredible dives 50-60 feet in the air and then pull up just before they crash.”
And that boom?
“When he reaches the very bottom of his dive,” Thelen said, “he pushes his wings down and air rushes through this specialized structure on his feathers to create that sound. To me, it reminds me of is the old Warner Brothers cartoons, where the Roadrunner is running way from Wile E. Coyote and he takes off into the desert with a “‘whoooom!’”
The nighthawk carries a certain cultural significance in New England. Henry David Thoreau spent nights on Mount Monadnock chronicling the activities of the nighthawk, likening the boom to “very distant thunder, or the fall of a pile of timber.”
With their mass migrations, Suomala said it’s possible to look out your window in late August and see a flock of over 1,000 birds heading south, a sight one’s not likely to forget. And even more unmistakable is the peent.
“With nighthawks, the peenting is so distinctive, that once you hear it once you can always recognize it going forward,” Thelen said.
It serves as a welcoming of summer, an announcement of dusk and, for one of Thelen’s summer volunteers, even a dinner bell.
“He knew as a kid that it was time to come home and stop playing outside when the nighthawks came out,” Thelen said.
The efforts of those volunteers paid off this summer, as a pair of courting nighthawks were spotted over the Keene State Campus, and another — with a fledged chick, was spotted downtown.
“We count ourselves lucky any time we find a nest and even luckier if we find one that has chicks that fledge,” Suomala said.
The on-campus nest appears to have been started and then failed — actually a “blessing in disguise,” Thelen said, as the building’s gravel roof was scheduled for replacement, and “it would have been really challenging to work around the bird.”
The other nest, in downtown Keene, yielded a fledged chick, but the outlook isn’t all blue skies; the last sighting of that chick placed it on the ground, having flown away from the nest and into the path of a number of ground-based predators. Still, it’s a positive sign.
“The fact that we found some and the bird hatched and fledged to the point that it could fly off the building was exciting,” Thelen said.
Efforts to locate nighthawks in Antrim and Hancock are ongoing as well.
Suomala said that one way to help preserve the nighthawk is to eat organic and support organic agriculture — not just here, but in South America, where the nighthawk migrates. The more pesticides used, she said, the more bugs that will be killed, depleting the nighthawks’ food supply.
“They’re part of this group that we don’t want to lose,” Suomala said. “We don’t want to know what its like to not have birds eating our flying insects. We want to figure out whats happening to them.”
For more information or to report a sighting, visit www.nhaudubon.org/project-nighthawk or email rsuomala@nhaudubon.org.