Students investigate the return of the county’s elusive barn owls

ADDISON — Students at the Patricia A. Hannaford Career Center are tracking a celebrity.
Rodney Olsen’s students in the Diversified Occupations (D.O.) program aren’t much interested in traditional paparazzi darlings these days, though. The celebrity they’re hunting is an elusive barn owl, which in birding circles brings star power a-plenty.
Picking over scavenged feathers an owl pellets, Olsen’s class thinks they’ve found the first conclusive evidence of a barn owl’s presence in the county in 10 years.
The last sighting of a barn owl in Addison County wasn’t a sighting at all — rather, a Ferrisburgh bird enthusiast heard the owl’s call one night in 1999. And at least 10 years before that, a survey of nests and breeding sites in the area turned up just two barn owl nests in Addison County.
“They’re gorgeous,” Olsen said, gesturing to a photograph of the bird on his classroom wall. Attached to the glass frame of the picture was one large, mottled brown feather.
The feather, it turns out, came from a barn in Addison that Olsen and his students believe was used as a nest by a barn owl last summer and fall. They uncovered several others like it, as well as a white-wash of bird droppings — and a mountain of 87 owl pellets, the compact balls of fur and bones that owls regurgitate after ingesting their prey whole.
Olsen first began investigating the old barn for signs of the owl after the barn’s owner, an Addison farmer, voiced concern about what taking down the building would mean for the owl’s habitat. 
Olsen’s students and budding owl researchers are unfazed these days by the pellets, which they are methodically dissecting to learn more about barn owls’ diet.
“The first thing that went though my mind was, ‘Oh boy, this is going to be messy and gross,’” said Aaron Gratton, a Bristol student in Olsen’s class, looking up from the pellet he was picking apart. “But it doesn’t disgust me any more.”
Gratton held up the miniscule fibula bone that was, at one point, a meadow vole’s leg. Then he pointed out the “shark’s fin” — a tiny protruding triangle on another bone that helped him identify it as the mouse’s humerus.
“This is the jaw of the meadow vole,” he said, holding up another fragile bone with his tweezers. “I call this the battle ax.”
Having already identified more than 100 different critters from the pellets they’ve dissected so far, Olsen’s students are adept at naming the species and identifying each specimen’s bones.
Take the meadow vole, which accounts for over 90 percent of the animal remains they find in the pellets. Shoreham resident Alex Dragon explained that he can tell the skull of a meadow vole from that of, say, a shrew simply by paying attention to the creature’s teeth. Picking up a meadow vole’s skull, he pointed at the two jagged lines of teeth — “like broken glass,” he said.
Olsen’s classroom pays homage to exactly this sort of hands-on learning.
“To the lab!” Dragon cried after unearthing a moth larva from his pellet. He rushed over to the two microscopes in one corner of the room.
In that same corner, Vergennes student Hannah DeMatties fished a zip-lock bag from a small freezer. The bag contained the body of a bohemian waxwing bird, the dead bird’s feathers awash in soft colors. Classroom assistant Sally Thodahl opened the bag, tipped the bird into her hand, and then placed it in DeMatties’ palms. Together, they fanned out one of the bird’s wings, examining its coloring. 
There’s also the mysterious box perched in the back of the classroom — home, it turns out, to flesh-eating beetles. The class will occasionally toss a carcass or skull into the opaque aquarium, and after the beetles do their work, the students are left with picked-clean skeletons to examine.
“(The beetles) come in pretty handy, and there’s a high gross factor,” Olsen said. 
These are the sorts of skeletons they use now as comparative guides when the students identify the bones they cull from the owl pellets.
The barn owl’s rarity in Addison County boils down to two factors: first, Vermont marks the northernmost boundary of the owl’s territory, so the raptors tend to be more abundant south of the state. 
Additionally, the owls prefer open meadows and fields, where they hunt their favorite prey: meadow voles. In Vermont, those open lands are disappearing as fields cleared by early settlers and farmers in the state convert back to forest.
Olsen, an owl and raptor enthusiast, began placing nesting boxes around the county 14 or 15 years ago as a way to study the creatures. He’d approach farmers and ask permission to set up a box, and never once did he run into any opposition. His students at the career center took up the task of constructing and placing similar units in barns about five years ago.
In the absence of a barn, Olsen explained, barn owls roost and nest in hollow trees or caves — but the boxes provide a flat, clear space in old barns that encourages them to lay their eggs.
Olsen’s class is tight-lipped about the location of the Addison nest — in large part because Olsen is worried that an influx of birders would disrupt the owl.
But the students, at least, are confident about their find. Their evidence suggests that the owl vacated its nest over the winter, but already signs of feathers, pellets and owl droppings suggest that their feathered star has returned.
“Oh, it’s back,” Olsen said.

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