On the prowl for owls

Research & Scholarship

Biology graduate student Justin Biggerstaff M.S. '26 releases a barred owl, nicknamed "Nyx," after retrieving a data tag the owl wore on a tiny backpack. (Photo illustration courtesy of Karl Neiswender. Original photo taken by Vitek Jirinec M.S. '15)

A high-pitched screech cuts the night air. Then silence. Minutes pass with only the low drone of crickets. Then you hear it, a soft, crescendoing hoot.

"There she is," says Matthias Leu, chair of William & Mary's biology department.

By "she," he means the female barred owl he and two students have come to capture. Two months earlier, they trekked out to the same spot of woods deep inside Newport News Park and caught this owl. After gingerly equipping her with a backpack that tracks GPS location, activity and temperature, they let her free. Tonight, they're back for their second attempt to retrieve the data.

The information she carries could help answer a question that reaches far beyond this forest: How is wildlife adapting to an increasingly human-shaped world?

Barred owls are just one of many species threatened by what scientists call the "Sixth Mass Extinction" - the rapid, human-driven loss of biodiversity catalyzed by climate change, pollution, habitat destruction and more.

Urbanization is a key culprit spurring that loss. Global urban land expansion, projected to cover up to 1.53 million square kilometers by 2050, could threaten the survival of more than 800 species, according to a 2022 study.

Leu and his students are studying how this urban growth is reshaping life for barred owls, an important avian predator in forest ecosystems. Once thought to live only in rural woodlands, growing evidence shows they now occupy more developed, infrastructure-dense landscapes.

"If we can understand how they use this habitat - where they roost, where they hunt and what areas they avoid - we can provide valuable information about the types of landscapes that support coexistence between wildlife and people," said Justin Biggerstaff M.S. '26, the biology master's student leading the project.

"This is one of the few studies that looks at the presence and activity of barred owls over a specific geography," added Leu. "By comparing our data with research from California, North Carolina and Louisiana, we can begin to paint a broader picture of how these owls behave across ecosystems."

Roads and habitat use

Biggerstaff, a Midwest native and ornithology enthusiast, is particularly interested in how roads impact the location and activity of barred owls.

"Owls are very auditory based animals," he said. "Almost all their features are adapted for noise."

Large ear openings encircled in soft, delicate feathers allow these predators to detect the quiet scurry of prey in the underbrush. Homing in on the sound, they silently glide downward, closing their talons before the unsuspecting victim knows what's happening.

"We predict that in a high-noise environment, next to a highway for example, the owls will struggle to hear their prey and so might avoid these areas," said Biggerstaff. "Or it could be simpler - the road noise might just be stressful and annoying to them, representing another risk."

Unfortunately, this risk tends to be greater for younger owls.

"Collisions are pretty rare, but they happen more often for first-year owls," said Biggerstaff. "To find an unoccupied patch where they can settle, they have to cross large stretches of landscape. When they encounter roads for the first time, they're unfamiliar with the hazard - and some don't make it."

The team's anecdotal evidence, gathered while spending hundreds of hours in the woods trying to catch owls, supports the hypothesis that the birds aren't as active when traffic noise is high.

A methodology to the madness

To answer questions about activity and habitat use near roads, the researchers have themselves become night owls - quite literally.

On a typical outing, Biggerstaff, Leu and one or two undergraduates trudge into the underbrush of a local park or private property. Lugging bulky aluminum poles, two thick metal stakes, a bag of Beats Pill speakers and other equipment, they search for the right patch of forest.

"We need a clear corridor of forest," Biggerstaff explained. "The trees act as guardrails, steering the owl into our nets."

After finding a promising spot, they set about erecting the net, which stretches some 36 feet long and 20 feet high. It's made up of three smaller nets layered together, each with a narrow pouch of mesh running its length to ensnare the owl. Complete, their trap looks like a massive volleyball net, nearly invisible in the dusk.

Matthias Leu and Brennan Tingley '26 work to untangle a net before heading out into the field. (Photo by Catherine Tyson '20) Matthias Leu (left), Justin Biggerstaff M.S. '26 (middle) and Brennan Tingley '26 (right) search for a place to set up their net. (Photo by Catherine Tyson '20) The net is anchored by two aluminum poles placed about 36 feet apart. (Photo by Catherine Tyson '20)

To attract barred owls, which are the source of the famous melody "Who cooks for you? Who cooks for you-all?" the team plays a set of owl calls from three speakers positioned under and around the net. This tactic capitalizes on the territorial nature of the birds.

"Each owl has its own section of forest, which it sometimes shares with a mate," explained Leu. "They are very protective of this territory and don't like it when other owls invade their privacy. By playing the calls we're kind of challenging their claim on this area." He said it typically makes them pretty mad.

A recorded owl call followed by the female's crescendoing response.

This technique, taught to them by Vitek Jirinec M.S. '15, a former Leu mentee who now works at the Integral Ecology Research Center in California, has been fairly successful in luring the owls into the nets. Going out most Thursdays and Sundays since April, they've caught owls at 13 sites in and around Williamsburg, James City County and Newport News.

Once an owl is caught, the team carefully extricates it from the net and slips a hood over the animal's head to calm it. Then they outfit the bird with a backpack that Biggerstaff stitched together in the lab, designed to carry a tracker that measures location, activity and temperature.

This work is not without its hazards. Both Leu and Biggerstaff have suffered the consequences of a well-timed talon. One particularly ornery owl, caught behind Biology Professor John Allen's house, managed to bite both handlers and bit Leu again on recapture. Another, after being placed down on the ground to take off, hopped around to face Leu and flew right at him.

"I saw these big eyes get closer and closer," he said, recounting the story good-naturedly. "I stood my ground and at the last second she veered off."

Despite the sometimes painful nature of their research, both mentor and mentee are jubilant when their hard work and late nights pay off with a successful capture. About 60 days after they outfit the owls with the backpacks, they head to the same location to find them and get the data, ideally before the battery runs out on their trackers.

They hope to continue fieldwork until the rechargeable transmitters fail. Biggerstaff will then begin decoding the first iteration of the wealth of data.

"Analyzing activity patterns can help us understand how much energy the owls are using," said Biggerstaff. "Comparing energy use with habitat use gives us an idea of the habitat quality. Generally, higher activity equates to a lower quality habitat because they're having to move around more to get the resources they need to survive."

Since all their owl capture sites are close to roads, the team hopes to sketch a picture of habitat quality in relation to these features.

Outsmarted by the owls

After waiting patiently for nearly four hours, the team decides to call it quits. Though they've heard plenty of chatter from the female owl, she hasn't fallen for their trap. Hooting from all angles at the Beats Pills with her male counterpart, she's flown every possible direction except for right into the nets.

Tired and disappointed, the trio switch on their headlamps and head over to the net. As they break camp they're serenaded by the two owls, hooting out their victory. It's almost as if they knew what the humans were up to.

"Now they're just rubbing it in," says Leu, stuffing the nets back into their bags.

The owls get the last word tonight, but as Biggerstaff says matter-of-factly, "That's science." They'll try again next time.

Catherine Tyson, Communications Specialist

Subscribe to W&M Weekly

• share by email
• share on Facebook
• share on X
• share on LinkedIn

• share by email
• share on Facebook
• share on X
• share on LinkedIn

Related Stories