Surveying the hawk owls of Glacier Park's burns

It hunts by day, has a long tail and is a fierce killer with a sweet trill of a song. It’s the northern hawk owl, and it’s one of Northwest Montana’s most unique birds.

Researchers from the Owl Institute, a Charlo-based nonprofit dedicated to owl research and conservation, have banded 60 hawk owls since their research began in earnest in 2005, according Matt Larson of the institute.

Along with his wife Jess, the two have been scouring the woods of Glacier National Park for several years in search of the owls. To date, the couple and other researchers from the institute have located 30 hawk owl nests in the Glacier Park region.

Most of the nests have been inside the Park. The birds prefer burned areas, and the Robert and Wedge Canyon fires on the east side have proven to be valuable habitat. The Red Eagle Fire on the east side also has become hawk owl territory.

The owls prey on small rodents and birds inhabiting recently burned forests. As forests regenerate, the resulting grasses and forbs create ideal habitat for voles and other small creatures, prey for the owls.

“All of our observations are in burned areas,” Matt said.

Matt said he watched a hawk owl catch and kill four juncos in half an hour. The meals didn’t go to waste — hawk owls cache their kills to eat later. When they’re raising broods, as many as half a dozen chicks, adult owls hunt relentlessly to feed their young.

Montana lies in the southernmost extent of their range. Hawk owls are circumpolar and live primarily in Canada, Alaska, Russia and northern Europe.

Owls pair up in late winter and begin nesting in March and April. The Larsons have spent thousands of hours skiing and snowshoeing in Glacier Park’s burned forests. The owls are difficult to spot unless they’re perched high on a tree, which they do when hunting, or if they’re calling.

The owls are cavity nesters, using natural cavities or abandoned pileated woodpecker nests as homes. The female sits on the eggs for about three weeks while the male feeds her.

The young take another three weeks or more to fledge. They fall out of the nest virtually flightless for the first few days. The young call out often for food, and adults guard them from predators until they can fly.

Unlike most owls, hawk owls hunt during the day. Their long tail gives them a hawk-like profile, but their facial features are all owl.

The Larsons will continue their research in Glacier Park this summer, in part through a grant from the Glacier National Park Conservancy. They also will survey recently burned forests on the Flathead National Forest.

A question they’re looking into is whether hawk owls are here to stay or whether they are simply a visitor to the burns. As the forest matures and grasses are taken over by young trees, the number of hawk owl sightings seems to decrease.

Of the 60 hawk owls banded over the years, only one has been recaptured — a six-year-old male recaptured just two miles from where it was initially captured, Matt said.