STRATTANVILLE – It’s been estimated that North America’s bird population has declined by 29 percent since 1970. Included in that decline, which represents almost 3 billion birds, is the common nighthawk, lending more importance to the recently concluded Seneca Rocks Audubon Society’s (SRAS) count of that species.
“They’re not listed by the U.S. Fish and Wildlife Service or any other agency as a species of special concern,” said Michael Leahy, a member of the SRAS’s leadership team. “In other words, [nighthawks] are not endangered or threatened, although their numbers have been decreasing, in some cases substantially.”
SRAS had two nighthawk counts in the area running concurrently from mid-August through early September, during the migratory period — one at the Oil City Marina to capture activity along the Allegheny River, and the other, more locally, at the Mill Creek Boat Launch near Strattanville to survey the Clarion River.
The Oil City nighthawk count has occurred for the past 22 years, while the Mill Creek watch has taken place since 2017.
“As far as I know, the nighthawk watches they are doing in Oil City and Mill Creek are the only organized nighthawk watches in existence in the United States, especially in Pennsylvania,” Leahy said. “There are some people [elsewhere] that will go out on an evening just to see nighthawks, but there’s no coordinated effort, no continuous effort.”
The common nighthawk breeds in North America, but migrates from Canada to South America in late summer and early fall, crossing the United States along several different routes.
“Nighthawks follow rivers [during their migration] because they’re bug eaters and there’s lots of bugs over rivers,” contributed Malcolm “Mal” Hays, an SRAS leadership team member. “They do fly at night, but they’re actually not in the hawk family; they’re in the nightjar family [a family of medium size birds, such as the whippoorwill].”
Hays started the count at Mill Creek Boat Launch six years ago, his curiosity being the impetus.
“I went up and helped them [at Oil City] with their watch. I asked them one day, ‘I wonder if they navigate the Clarion River like they navigate the Allegheny?’ They said, ‘Well, the only way you’re going to find out is go down there and watch.’
“I went down to the [Clarion] river in 2017 with Larry Towse and, by golly, we had nighthawks flying overhead. We’ve been counting ever since.”
The 2022 watch began on Sunday, Aug. 14 and continued nightly, rain or shine, from 6 or 6:30 p.m. until dark and until no nighthawks were counted for several consecutive days. The final count came this year on Wednesday, Sept. 7. Including Hays and his almost constant counting partner, Towse, 26 individuals joined the watch.
“Larry [Towse] and I were down [at the boat launch] almost every night and then different members of our group came down various nights. We’re usually sitting in lawn chairs with our binoculars and counting them as they go,” reported Hays.
“They do fly in the rain, though we aren’t out there if it’s an absolute downpour or if it’s thunder and lightning. We usually sit in our cars until it passes over and the rain slacks off and then we’ll get out and start watching again. The 17th of August it rained the whole time Larry and I were down there counting, that doesn’t keep them from flying.”
This year saw the second highest count since Hays began watching along the Clarion River, with 672 nighthawks observed. Despite the high tota, the general trend has been one of declining numbers — 329 in 2021, 394 in 2020, 560 in 2019, 719 in 2018 (the most counted), and 567 in 2017.
The general decline is attributed to a loss of nesting habitat and insecticides which are killing the nighthawks’ primary source of food, flying insects.
Nighthawks don’t build nests, but rather lay their eggs on the ground or amongst gravel which provides natural concealment, particularly in areas where vegetation is sparse. Because of this, changes in the way roofs are constructed may have actually also played a role in the declining numbers.
“[Nighthawks] like to nest on flat roofs. It used to be flat roofs were made with layers of wood and overlaid with tar paper. They would pour tar and embed gravel into the tar to hold the tar paper down. These were a preferred nesting area, [nighthawks] would move a few pebbles to make a depression and lay their eggs directly on that. The eggs were camouflaged by the gravel,” explained Leahy.
Continued Hays, “The gravel roofs on buildings were the perfect habitat for the nighthawk to lay eggs. When people stopped putting gravel roofs on buildings and replaced them with rubber or metal or whatever, they lost a lot of their nesting habitat.”
This year’s nighthawk count will, as in previous years, be submitted to the Pennsylvania Society for Ornithology (PSO). In some respects, the PSO serves as a repository of data and other information, available to both the general public and others interested in conducting more professional research.
“What we’re doing is a thing called ‘citizen science.’ Although we do have scientists in our midst [in the SRAS], most of us are not scientists, although we’re doing scientific research to a degree. We’re looking at the long-term effects of not only habitat loss, but climate change, all kinds of things. We’re compiling all this information and submitting it so hopefully actual scientists or ornithologists might be able to use it,” commented Leahy.
“As ‘citizen scientists’ we are kind of keeping our fingers on the pulse of things to help the environment and the animal world and scientists in general.”