Pennsylvania Northern Harrier Project Seeks Public’s Help to Protect Threatened Bird
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Asia Tabb
aired; July 21, 2026
A coalition of conservation organizations is asking Pennsylvanians to keep an eye on the skies—and the grasslands—as a new statewide effort works to better understand one of the Commonwealth’s rarest birds of prey.
On The Spark, Sean Murphy, ornithologist with the Pennsylvania Game Commission; Jen Sliko, landscape program specialist with Audubon Mid-Atlantic; and Bracken M. Brown, biologist-naturalist with Hawk Mountain Sanctuary Association, discussed the Pennsylvania Northern Harrier Project, a collaborative research effort aimed at protecting the state’s threatened northern harrier.
Often called the “marsh hawk,” the northern harrier is unlike many of Pennsylvania’s more familiar birds of prey.
“It’s a very unique raptor, especially in Pennsylvania,” Murphy said. “They feed over wetlands and open grassland habitat, primarily on small mammals like mice and voles, and they’re listed as a threatened species under state regulations.”
Unlike red-tailed hawks and many other raptors that nest in trees, northern harriers build their nests directly on the ground in expansive grasslands and marshes—a behavior that makes them especially vulnerable as Pennsylvania’s landscape continues to change.
Researchers say the bird’s population has been declining for decades.
“The second Pennsylvania Breeding Bird Atlas documented a 43% decline in confirmed harriers across the state,” Brown explained. “More recent research suggests that decline is now closer to 50 percent.”
Brown said the loss of large grasslands, changing farming practices, suburban development and even routine mowing during nesting season have all contributed to the species’ decline.
“We might be assisting the decline of harriers through accidentally mowing them to death because most people aren’t expecting a hawk to be nesting on the ground,” Brown said.
The northern harrier also serves as an important indicator of ecosystem health.
“Raptors are great indicators of healthy ecosystems,” Brown said. “If you have enough prey items lower in the food chain to support the predator, that’s a good indication of a healthy area.”
Sliko said scientists still have significant gaps in their understanding of the species, making the project especially valuable.
“One of the reasons it’s important is because we don’t know a lot about it,” she said. “There has been a decline in northern harriers, but we’re not entirely sure why. This project will help us understand what’s happening and what we can do to bring them back.”
Over the next several years, researchers will revisit historic nesting sites, investigate new sightings, study nesting habitat and, for the first time on the East Coast, use GPS transmitters to follow Pennsylvania’s breeding northern harriers throughout their annual cycle.
“We’ll be riding along with these birds for the next three years,” Brown said. “We’re trying to fill in a lot of information gaps about where they’re nesting, where they’re going and how we can better protect them.”
A key part of the project depends on public participation.
The research team is asking birdwatchers, hikers, farmers and anyone spending time outdoors to report possible northern harrier sightings, especially during the breeding season.
“We really rely on a strong volunteer effort,” Murphy said. “If people are out in suitable habitat and they see a harrier, we’re looking for them to report it so we can follow up and hopefully identify nesting birds.” 
Sliko emphasized that expertise isn’t required to help.
“It’s okay if you’re wrong,” she said. “We’re going to double-check everything. We’d rather receive too many sightings than not enough because people were afraid to report what they saw.”
The project also highlights the important role private landowners play in wildlife conservation. Because most of Pennsylvania’s open spaces are privately owned, researchers hope future findings can help farmers and landowners balance productive land management with habitat conservation.
“If that’s the case, how can we work with landowners so they can still have profitable land but manage it in a way that’s not mowing over baby birds?” Sliko said.
For those hoping to spot a northern harrier, Brown recommends visiting large grasslands, marshes and reclaimed mine lands, particularly along the Susquehanna and Delaware river corridors. The birds fly low over open fields and are recognizable by a distinctive white patch at the base of their tail.
The researchers say every observation helps—and every Pennsylvanian can play a role in protecting one of the state’s most unique and threatened raptors.