Irritable Owl Syndrome

The barn owl sat on top of the light pole, watching the small gulley.  As the sun set, the owl slowly opened its eyes—a more complicated move than you might think as each eye had three eyelids.  For several minutes, the owl studied the gulley, looking for food.  Even as the sun set, the owl continued to watch—owls' eyes aren't  really "balls" but more like tubes that have excellent night vision.

After several minutes, the owl let out a single "HOOT."

Almost a hundred feet away, the field mouse sat under a small cedar bush, completely hidden from the owl.  Already fairly still, the sound of the owl froze the rodent.  Now, the mouse would not risk moving even a whisker.

Field mice made up a sizable part of the diet of almost every predator that lived along the Brazos River in Texas.  Owls, hawks, bobcats—even rattlesnakes—hunted the defenseless rodents.  But the owls—the silent killers—were especially frightening.

The owl slowly moved its large head.  While he had a fairly wide field of vision due to the shape of his eyes, he only had binocular vision for about 70 degrees directly in front of him.  As he slowly moved his head, every square inch of the gulley could be closely examined for movement.

Once again, the owl emitted a single long "HOOOOT."

The mouse was safe since there was no direct line of sight between him and the owl.  At least, as long as he stayed absolutely still, he was safe.

The owl shifted his head slightly and using small facial muscles, reshaped the dish shaped depressions surrounding his ears.  The owl's hearing was excellent, but in particular, he could hear the small sounds that prey would make as it moved through vegetation.

"HOOT," went the owl.

The owl’s ears were located on his head slightly asymmetrically, giving his head a slightly lopsided look, but enabling the winged predator to detect the slightest time difference it took a sound to reach each of his ears.  Able to detect time differences as minuscule as 30 millionths of a second, the owl could accurately locate the source of any sound.

"HOOT," went the owl.

By now, the mouse was terrified.  If he waited long enough, he knew that the owl would have to move on to find a meal.  Why wasn't the owl leaving?  He should have moved by now.

"HOOT," went the owl.

The mouse was sure now that the owl must know where he was hiding.  A short distance away, just past the bush he was hiding under, was a small hole under a rock—a much better hiding place.  Perhaps the mouse should move to the safer spot.  And he should move before the owl spotted him.

"HOOT," went the owl.

Unable to wait any longer, the terrified mouse scampered towards the hole and safety.

From 100 feet away, the owl heard the faintest sound coming from his right.  He quickly turned his head until the sound was reaching both ears simultaneously, meaning that his head was facing directly towards the mouse.  Almost immediately, his excellent binocular vision located the almost invisible gray mouse in the growing darkness.

The owl was completely silent as he glided down the gulley and snatched up his meal with his talons.  The mouse never knew what killed him as the long strong claws ripped through his body.  The owl now strongly beat his wings as he climbed out of the gulley and flew the short distance back to the top of the utility pole next to the barn where he enjoyed the first of several small rodents he would eat that night.

From a porch fifty feet away, where the two old ranchers sat in their rockers, the owl could be seen silhouetted in the last twilight.  They, too, had listened to the hoots of the owl, for several minutes.

"Didn’t even take ten minutes.  Told ya so," said Mike as he held out his hand.

Kent shifted in his rocker and reached into his hip pocket, pulling out a clip of bills.  Peeling off a single dollar to put in the outstretched hand, he said, "Should have bet on the owl."

"You're just irritated because you lost again," Mike said as he pocketed the bill.