Great horned owls: Silent hunters leave their mark

It had been a rabbit, I was certain of that. Rabbit fur was blown evenly in a circle that extended widely in each direction across a cross-country ski track.

I was looking at a bunny explosion.

The answer was on the far side of the circle: wing marks in the snow, feather tips engraving evidence as the cause of the explosion pumped hard for lift.

It had to be a great horned owl.

It had come silently from the darkness of the previous night, hitting the rabbit hard with extended talons. Fur blew with the impact. The owl flew off with the rabbit impaled beneath it, talons instantly squeezing hard enough to break the backbone.

If ever it was true, the victim never knew what hit it.

This was in February, and my guess is that the hunter was a male owl hunting to feed its mate. She would already have been on their nest, incubating eggs, two or three. These owls nest very early in the year, months ahead of other Minnesota birds.

Two great horned owls live somewhere in our Orono neighborhood. I heard what I assume was courtship conservation in November. These birds call with the voice of an opera basso profundo.

Owl voices are deep and low because those sound frequencies travel best through the tangle of wooded land.

Often you hear one owl call, then wait and wait for an answer, if an answer is there. My courting owls answered quickly, without hesitation. They were the couple that finished each other's sentences.

Scientists call this duetting, common when the birds are establishing territory, anticipating nesting by a month or two.

The low nighttime hooting of these owls enters our house almost felt before heard. I don't hear the calls as much as become aware of them. Great horned owls calling on a winter night is a birding highlight for me.

The sturdy appearance of this bird, commanding from a tree-limb perch, holding you with nonsmiling eyes, belies its substance. The average great horned owl weighs only about 3 pounds.

This owl, however, can carry away a prey animal weighing 8 or 9 pounds. That's like a 150-pound man walking away with a 450-pound calf.

Great horned owls live everywhere in the Americas, from northern tree line to the bottom of the Western Hemisphere, Tierra del Fuego.

Given the known average population density of this owl in this part of the world, each pair probably has a territory of roughly 10 square miles. In theory, then, Hennepin County should be home to about 60 pairs of great horned owls.

Watch for large stick nests in now-leafless deciduous trees. Sometimes you will see a head poking from the nest. In winter months this is almost certain to be a great horned owl on eggs, or brooding young birds.

Lifelong birder Jim Williams can be reached at woodduck38@gmail.com. Join his conversation about birds at www.startribune.com/wingnut.