This post originally appeared on Scientific American
We have to assume it was a squirrel, but we know how it died. It died squirming and convulsing in the talons of an owl, locked in by the bone ratchets the owl shares with other raptors. Based on what was left behind, we also know that the attacker was likely a Great Horned Owl or a Northern Hawk Owl with a wingspan between 86 and 87 centimeters. All of this we can glean from a striking impression of a deadly strike.
There is perhaps no evidence of a kill more beautiful than these wing-prints left in the frigid Timiskaming, Ontario snow. Like throwing flour on the invisible man, the snow lets us see the tracks of an invisible predator—invisible at least to the squirrel.
With hearing good enough to sense rodents and other prey inches under the snow, owls feed by plunging their talons deeply through the drifts and into their prey. In the summer, the last thing many small mammals see is the owl. In the winter, strategies change, and many owls supplement their mammalian meat with that of small ground-dwelling birds like grouse. No matter the food, the killing itself isn’t pretty. Hawk owls in particular eviscerate small mammals before eating their heads and organs, thereafter caching the remains.
An owl can triangulate a scurrying vole better than you or I ever could, but the kill is not always so graceful. The hole at this kill site is likely enlarged by the repeated digging that is necessary to finally pierce a vole or grouse.
Often in science, we are unfortunately relegated to tangential, rather than direct, observation. To test the most obtuse “multiple universe” theories, for example, we might be able to look for boundaries where universes affect each other, but never the universes themselves. We have never seen a single electron, but stipulate its existence because of how atoms interact and how chemical reactions progress. Likewise, we never saw this owl swoop from the sky to puncture a helpless squirrel, but the wing-prints tell the story, a story about survival. The owl’s wingtips etched a testament to this unseen battle in the Canadian snow.
Sitting happily atop the food chain, we are oblivious to the intricacies of animal survival until our attention focuses on it. It takes something striking to raise the minutia of daily subsistence to conscious wonderment. Sometimes it takes an impression of feathers, frozen, somber. It was the last thing the squirrel ever saw.
Image: Gavin Murphy
John Wyndham wrote in The Midwich Cuckoos:
“I wonder if a sillier and more ignorant catachresis than “Mother Nature” was ever perpetuated? [...] because nature is ruthless, hideous, and cruel beyond belief”
And yet we can see the the beauty in the picture above, and in the events that caused it.
Well said.
Awesome photo, and a good article, beautiful writing. But… “…the attacker was likely a Great Horned Owl or a Northern Hawk Owl with a wingspan between 86 and 87 centimeters.” The Northern Hawk Owl is much smaller than the Great Horned Owl, there is no way that the wingspans are comparable. The book I have at hand, The Sibley Field Guide to Birds of North America, 2003, lists the Northern Hawk Owl span as 28in/71cm, and the Great Horned as 44in/111cm. Other sources on the web give slightly differing figures, but as you can see the size difference is vast. Assuming that the measured width is correct, and accounting for the possibility that the bird’s wings may not have been at full extension when the impression was made, the Long-eared Owl (36in/91cm) or Short-eared Owl (38in/97cm) are a possibility. If the wings were nowhere near full extension then, of course, it could be a larger species such as the Great Horned, Great Gray, Snowy, or Barred Owl, but if it was a Northern Hawk Owl it would need to be on steroids.
And “We have to assume it was a squirrel…”? I don’t see any tracks leading up to the site of the catch, although admittedly there isn’t a lot of space between the bottom of the frame and the area that has been swept by the bird’s tail feathers. Instead of a squirrel I suspect it was something that was burrowing under the snow, perhaps a Meadow Vole.
Excuse me for seeming a bit pedantic, but we birders can be an obsessive lot!
Thanks for your input. You’re right, a number of the choices that I had to make for the piece were based on assumptions.
First, because of the range of wingspans, I had to guess at the owl. I’ll defer to your birding skills.
Second, whatever the animal was, it was definitely traveling underneath the snow, but I went with a squirrel because vole/grouse would likely be unknown to the reader.
I applaud your pedantry sir!