Great horned owls are chattering, hooting, clacking. What does it mean?

Earlier this winter just after midnight, my parents were binge-watching "Game of Thrones" when they heard a thunderous chorus of hooting outside their home in Shakopee.

My parents have relatively poor hearing, but the enthusiastic activity drowned out the din of the TV and startled them.

"It was so loud, and so clear, it felt like the sound was coming through the walls and roof," said my mom, Katie Ekblad. "And we keep the volume up high, because we're both pretty deaf."

"What the heck is going on?" My stepfather, Jeff Ekblad, wondered.

Intrigued and somewhat alarmed, they went outside and investigated. Listening from their backyard deck, two owls (one in the front, one in the back) hooted back and forth — a boisterous conversation of sorts that carried on throughout the night.

"It was incredible," said Jeff, recounting the story.

"Amazing," I said. "But I have questions." He did, too.

For example, Minnesota is home to at least 12 owl species, but which one, we wondered, was hooting in their backyard? Also, what, if anything, did the duo's nighttime conversation mean?

Call it a "hootdunit."

My parents are nature lovers — and they enjoy identifying birds at their many bird feeders. Their home has mature hardwoods and conifers, and their backyard is bracketed with hedges — an intentionally overgrown vegetative wall that provides solitude and privacy and wildlife habitat. My mother also maintains a backyard flower garden, among other plantings.

Suburban Shakopee isn't the wildlife reserve of the Serengeti, but my parents' backyard also borders a cemetery — a sprawling open area sprinkled with trees and grass that eventually runs into a local park (and a large pond) and the grounds of an elementary school. The combination of habitats attract myriad wildlife species to their backyard, from deer to raccoons to squirrels to jackrabbits and everything in between, including the occasional possum. Raptors, in particular, abound. Red-tailed hawks patrol the cemetery, picking off mice, gophers, cottontail rabbits and other critters. Bald eagles have perched in my parents' yard, a perfect vantage point overlooking the cemetery-slash-hunting grounds.

"We've even had a Cooper's hawk nest in a tree in the backyard, and we've also had an owl sit in a nest in one of conifers right next to our bedroom," said my stepfather. "We've heard it hooting a lot over the years, but we've never seen it. This winter was the first time we heard two owls hooting at each other."

Karla Bloem, executive director of the International Owl Center in Houston, Minn., is considered one of North America's foremost owl experts. Could she identify the mystery owls at my parents' house and explain the hooting?

"Well, it's definitely a great horned owl, but without hearing the vocalizations, I can only guess about the hooting," Bloem said. "I get questions like this all the time and tell people to get a recording. Even a bad recording can tell you quite a bit."

Nicknamed "tigers with wings," great horned owls are fearless and feared birds of prey. They are one of the few animals that will kill a skunk and have been known to attack cats, small dogs (although rare), waterfowl and other raptors, including other great horneds. Most of their diet is comprised of small mammals. They generally kill by impaling their prey repeatedly with their powerful talons.

Great horned owls are a special passion for the owl expert. Bloem has studied 10 captive birds throughout the years and currently cares for four. She's recorded the vocalizations of roughly 40 (captive and wild), including 25 over a period of time.

Most birding sources, Bloem said, misrepresent great horned owl vocalizations as simple screeches and hoots.

"This is an oversimplification," she said. In fact, the birds have several kinds of hoots, squawks and chitters. They also hiss and clack their bills. Bloem explained some: Chittering is like owl chattering ("quiet conversation through extreme annoyance"); hisses and clacks are a "get away" warning to other birds; and hoots are relative to mating or when birds are "excited … good or bad."

"We can tell wild birds apart from their hoots," she added. "We track them by voice, instead of banding like other birds."

Based on the news of the night in Shakopee, Bloem believed the hooting in my parents' backyard was either a territorial dispute between birds or a mated pair performing their annual courtship ritual. Winter is the great horned owl breeding season. Some call it the hooting season. The birds, which use the nests of hawks and other animals, will lay eggs throughout February and into March. Because of the cold weather, incubation is required nearly 24/7.

Secretive, nocturnal birds that are more likely to be heard than seen, great horned owls have big, yellow eyes and feather tufts on their heads called plumicorns that look like horns. Bloem said they are among the most recognizable owls. Their eyes don't move in their sockets, but they can swivel their heads more than 180 degrees. The so-called perch-and-pounce predator has superb night vision, with wide wings and soft feathers that allow it to fly stealthily.

"Most owls have a velvety pile on the top surface of their wings to help them keep quiet … It's like wearing a fleece jacket instead of a nylon one," Bloem said.

The owl species has adapted well to rural and suburban environments, Bloem said, making my parents' experience not all that unusual.

"What happened at your parents' house is common, and more people would hear the hooting and other vocalizations if they just got outside at night and listened."

Tori J. McCormick is a freelance outdoors writer. Reach him at torimccormick33@gmail.com.