[Plus Gregorian Chants, Chuck Wagon Gang Gospel, Navajo flute, Beethoven’s 9th, Mozart Horn Concertos, old-timey country, cowboy and hillbilly, bluegrass, big band, folk, blues and songs of the Civil War, WWI and WWII thrown in for the discerning night predator]
Bear with me here. This is a bit complex for a dumb old redneck to explain.
The problem: If you’re a person trying to keep free ranging chickens some of them will insist on sleeping in the trees. If you also keep guineas, all of those will nest in the trees. The guineas tend to bunch up in several clumps in the treetops, and they whisper and burble to themselves or to one another in their dreaming.
Enter, the owl:
“An Owl’s range of audible sounds is not unlike that of humans, but an Owl’s hearing is much more acute at certain frequencies enabling it to hear even the slightest movement of their prey in leaves or undergrowth.
“Some Owl species have asymmetrically set ear openings (i.e. one ear is higher than the other) – in particular the strictly nocturnal species, such as the Barn Owl or the Tengmalm’s (Boreal) Owl. These species have a very pronounced facial disc, which acts like a “radar dish”, guiding sounds into the ear openings. The shape of the disc can be altered at will, using special facial muscles. Also, an Owl’s bill is pointed downward, increasing the surface area over which the soundwaves are collected by the facial disc. In 4 species (Ural, Great Gray, Boreal/Tengmalm’s & Saw-whet), the ear asymmetry is actually in the temporal parts of the skull, giving it a “lop-sided” appearance.
“An Owl uses these unique, sensitive ears to locate prey by listening for prey movements through ground cover such as leaves, foliage, or even snow. When a noise is heard, the Owl is able to tell its direction because of the minute time difference in which the sound is perceived in the left and right ear – for example, if the sound was to the left of the Owl, the left ear would hear it before the right ear. The Owl then turns it’s head so the sound arrives at both ears simultaneously – then it knows the prey is right in front of it. Owls can detect a left/right time difference of about 0.00003 seconds (30 millionths of a second!)
“An Owl can also tell if the sound is higher or lower by using the asymmetrical or uneven Ear openings. In a Barn Owl, the left ear left opening is higher than the right – so a sound coming from below the Owl’s line of sight will be louder in the right ear.
“The translation of left, right, up and down signals are combined instantly in the Owl’s brain, and create a mental image of the space where the sound source is located. Studies of Owl brains have revealed that the medulla (the area in the brain associated with hearing) is much more complex than in other birds. A Barn Owl’s medulla is estimated to have at least 95,000 neurons – three times as many as a Crow.
“Once the Owl has determined the direction of its next victim, it will fly toward it, keeping its head in line with the direction of the last sound the prey made. If the prey moves, the Owl is able to make corrections mid flight. When about 60 cm (24″) from the prey, the Owl will bring its feet forward and spread its talons in an oval pattern, and, just before striking, will thrust it’s legs out in front of it’s face and often close it’s eyes before the kill. Click here to see a Great Gray Owl using it’s hearing to catch a small rodent concealed under snow.”
Got all that? The feathered cones or funnels around the eyes of the owl act as parabolic sound receivers. They work in concert using parallax to locate the positions of prey.
Or the way this vintage pocket range finder used parallax to accurately provide distance for photographers:
Okay. So how’s a poor old redneck who has guineas sleeping in the trees being picked off by owls carrying secret weapons, a guy who has four cats he needs to consult regularly on important matters, a man with a herd of free ranging chickens supposed to curtail such nonsense?
Answer: Echoes. Noise reflected from all directions 24/7.
I began by looking for castoff disk harrow blades, woks, pot lids and parabolic tv dishes and placed them in strategic locations around the place.
At the time my CD player would only take five CDs, so until the player wore out it was Gregorian Chants, Mozart Horn Concertos and Carlos Nakai Canyon Suite [Navajo flute] here day and night, outdoors maximum volume. But by the time that player went Communist, months had passed and I hadn’t lost any more guineas at night.
So there I was knowing how to keep the owls somewhere else, owning a couple of hundred CDs, but cats, chickens, guineas all mutually agreed on one point: it was time to broaden my horizons music-wise. Even the coyotes were sick of Mozart and the cats were beginning to open confessional booths for the chickens.
Enter the Coincidence Coordinators:
A lady on the Kerrville FreeCycle Yahoo group advertised she’d like to give away a Sony 200 CD disk player because she was using an MP3 or some such thing for her music. I called her and made a special trip to town to pick it up, swing by the Habitat for Humanity Recycling Store to buy an old receiver and a pair of speakers large enough to wiggle the ears of the deer population.
Eventually that player wore out. But as luck would have it, I found a 300 CD player at the Salvation Army Thrift Store and a willingness on the part of the guy at the counter to do some horse trading, which I’ll describe another time, that horse trading in thrift stores. http://tinyurl.com/3t4ums9
Yeah, it ain’t the way the smart alecs save their chickens from predation by owls – I don’t know how they do it. But this old white trash redneck fixed them owls but good and the chickens and cats are in Rock and Roll Heaven.
Rock and Roll Heaven by the Righteous Brothers