There aren’t too many natural sounds that stump me around my home north of Fairbanks. After several years living here, and sixteen in Alaska, I feel like I’ve pretty much heard it all. So late last night, as Amy and I were just getting back home after an afternoon down in Denali National Park, I stopped dead when an unfamiliar screech echoed across our little valley.
Fox, I thought at first, perhaps a young one still learning to bark. But our dog, who dislikes foxes and takes great joy in a fruitless chase after them, showed no interest. Strange, so probably not a fox.
The sound continued every few seconds, eventually joined by a second. Listening, Amy and I were certain the sound was coming from the trees, so a bird seemed the most likely culprit. But what makes a sound like that? Still unsure, I went for my digital recorder and mic and made a quick recording. Here it is:
Scanning the tops of the trees, nothing revealed itself, but the critters, whatever they were, were certainly up high, probably perched on the very tops of the spruces. I was confident now, given the late hour, the dim light, and the genuinely odd sound, that we were dealing with an owl. My thought was Northern Hawk Owls, not a species that I heard vocalize very often.
I was right about the owl, wrong about the species.
A half hour later as we lay in bed, the sound could still be heard through the cracked window. Amy went to her iPad and started doing a little searching. Within a few moments I heard the distinctive hoot of a Great-horned Owl coming from her device, and then, as part of the same track, a screech identical to the one out our cabin door.
Juvenile Great-horned Owls, it turns out, do not share the calm, classic hoot of the parents. Instead, they screech. Apparently we had a pair of youngsters vocalizing in our yard. Mystery solved.
Here is a link to a set of vocalizations of Great-horned Owls from the Cornell Laboratory of Ornithology, where Amy solved our mystery. The juvenile calls can be found in the Calls section in the first track toward the end.
I knew of course, that Great Horned Owls make more calls than just the familiar territory-defining hoots. I’d heard wild owls clack their beaks when upset, and once or twice heard adults make bark-like sounds. But I wasn’t fully aware of the diversity of sounds. One researcher in the 1930s (Baumgartner 1938) referred to Great Horneds making “an indescribable assemblage of hoots, chuckles, screeches and squawks”.
Females in particular will utter hawk-like screams during nest defense, pairs will duet with slightly differing songs, young in the nest will screech, chip, whimper, and purr each in a maddening array of volumes and pitches.
No matter how much I think I know about the place I live, I find there are always, ALWAYS, new things to learn. Sometimes those new things screech from the trees right outside my door.
Information in this post I drew from the Birds of North America Account for Great Horned Owls:
Artuso, Christian, C. Stuart Houston, Dwight G. Smith and Christoph Rohner. 2014. Great Horned Owl (Bubo virginianus), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/372
And the quote comes from this article:
1938. Courtship and nesting of the Great Horned Owls.Wilson Bull. 50:274-285.
Same experience earlier this summer! Fortunately it was during the daytime. Was walking a river bank, heard this screech, and navigated around until we found two owlets along the bank. A great truism about our surroundings, there is always more to learn.