The View from Heifer Hill: A midsummer night's scream

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It might be that I spend more time in the woods after dark than I do during the light — that's when much of the best stuff happens. For example, that's when baby beavers come out of their lodge.

One night this summer, I took some of my favorite people, Margaretta, Isabelle and their dad, David, out to visit some of my favorite beavers. The beaver kits made us wait until 9 p.m., but then put on a great show. It would take us an hour to hike back in the dark, so this would be a late night. The first part of the hike was an uphill bushwhack to get to the trail. We had gone just a bit farther than where I thought the trail should be, when the darkness was rent by an unholy shriek. I know there is nothing to be afraid of in the woods at night. I know it. Still, there was no preventing the curdling of my blood in that moment.

In the giddy wave of recognition that followed, I knew what would come next, the full-throated query of the Bard, the barred owl, that is: "Whoo cooks for YOU? Who cooks for YOU all?"

We are all familiar with this standard call of the barred owl, but that is only a small part of what barred owls have to say. When the pair (and sometimes their kids) get together for a "hootenanny," listeners are in for a treat. Researchers have identified 13 distinct barred owl vocalizations so far. The terms these scientists use to label the sounds — twitter, gurgle, two-phased hoot, inspection call — do nothing to evoke the astonishing quality of the sounds produced. Their sounds have been more graphically described as "maniacal cackling," "caterwauling," and "demonic monkey hooting." The owls' "hooOOOOAHHHs" put country music fans to shame.

Barred owls are among the few bird species in which the female also "sings." Because they mate for life and stay on the same territory year-round, you will hear the same birds and their conversations year-round, though they tend to be most vocal during the late winter breeding season.

David Kroodsma, author of "The Singing Life of Birds," has made some interesting observations about barred owls. He was the first to recognize that the female and male calls can be distinguished by the amount of vibrato on the "all."

The males end their standard hoots with a simple "YOU all," while the females (whose voices are pitched higher) drawl it out, "YOU aaaallllllllll."

Listen. Soon you'll be able to reliably distinguish the males from the females by the vibrato. Your friends will be impressed. If you listen closely to their duet performance, you will be able to distinguish her voice from his, and will hear some of the calls that are distinctly hers.

But what are they talking about? The scream we heard that night is called the "alarm shriek," so perhaps the owl was as startled as we were. But what about the crazy monkey sounds? Are they keeping their oral history alive?

The "Who cooks for YOU?" hoots often come as a call-and- response from distant parts of the woods. Are mates keeping track of each other? Wouldn't it be strange if human couples behaved this way in, say, grocery stores or at Gallery Walk?

The owls' din certainly seems to defeat the purpose of silent flight. The crazy caterwauling duets usually take place when the owls are together, and that ruckus may be letting other barred owls around know that they are a virtuosic team and not to be messed with. Regardless of the evolutionary purpose, it sounds like they're having fun.

Darkness comes earlier every day now, which gives us more time to be out in the woods at night. That's when much of the best stuff happens. There's nothing to be afraid of. What's not to love about a good spine-tingling scream.

Patti Smith is a naturalist at the Bonnyvale Environmental Education Center. The View From Heifer Hill, a feature on the nature of our region, appears in this space the first Saturday of each month. Patti welcomes your feedback at patti@beec.org.

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