Posted on 01/18/2022 8:35:41 AM PST by Scarlett156
Trailing-edge noise is the dominant source of sound from aeronautical and turbine engines like those in airplanes, drones, and wind turbines. Suppressing this noise pollution is a major environmental goal for some urban areas.
In Physics of Fluids, researchers from Xi'an Jiaotong University used the characteristics of owl wings to inform airfoil design and significantly reduce the trailing-edge noise.
"Nocturnal owls produce about 18 decibels less noise than other birds at similar flight speeds due to their unique wing configuration," said author Xiaomin Liu. "Moreover, when the owl catches prey, the shape of the wings is also constantly changing, so the study of the wing edge configuration during owl flight is of great significance."
Trailing-edge noise is generated when airflow passes along the back of an airfoil.
(Excerpt) Read more at phys.org ...
My wife and I were watching a cardinal on the railing of our deck, admiring the beauty. Wham, a hawk snatched it up in a shower of feathers. Pretty cool.
I was sitting on my porch and saw a Red Tailed Hawk on my neighbor’s roof. It swooped down beside the deck and flew off with a cat in its talons.
It was your game.
Jays are not nice. They’re sort of a junior version of crows. I like them.
I’ve seen hawks and owls hunting aplenty. I also saw the crazy dance that mating hawks do when they lock talons and spin toward the ground. I did have a camera with me that day but I didn’t want to stop watching for a second.
BS. The chicoms are actually experimenting with owl viruses.
Nature!
Better luck next time!
I don't, they're carnivores and I'm winning the war against them.......
I'd be happy to send you the bodies of the deceased if you wish.......LOL!
We're not talking Vincent Van-Gogh "Cutoff an ear crazy," are we?
How about Edvard Munch, The Scream done in 1893 kind of crazy?
Many years ago, was back visiting the folks in Montana and took a walk around their small farm. The south end of the farm was populated with Ponderosa pine of various sizes and ages. Dad had told me he had seen a pair of Great Horned owls around.
Anyway. Traipsing along lost in a haze of memories, I was enjoying the smell of the pines and crunch of the needles and small twigs and cones, when I was brought out of my time-travel reverie with a heart-stopping shock when a Great Horned owl skimmed silently, and slowly, over my head but a couple of feet above. It was all wings, with a wing-span of some six feet or more, and gave me one HELLUVA start (a “dial 9-1-1 and charge-the-defibrillator” kind of start). Completely silent. I’ve had geese and large ravens glide over but their glide is an audible whisper. The owl was utterly soundless. If I had been aware, I could have nearly touched it, so low was its glide path. Very cool.
It isn’t the wing but the feather...owl feathers are fringed.
Cool! I know they’re around but I seldom see them here because lots of TREES. When I lived in Eastern Colorado I used to see them quite a bit, however - the big ones. I think barn owls? There were all kinds of birds of prey out there - I saw kites, kestrels, hawks all the time. I’ve seen hawks do their mating dance where they grasp each others’ claws and twirl toward the ground!
One morning I heard something going on outside where my doves were in their cage. I went out and a GOLDEN EAGLE was trying to get in the cage! I saw him a few more times after that - he seemed to be a juvenile and kinda down on his luck.
No, thanks. The “trailer park boys” actually killed one of the jays - it had a bad wing although it could still fly. It hung around here for years. They started saying on twatter that they needed to “kill a bluejay.” I felt they were talking about me - it’s a long story, but I was having some serious problems with these guys - and I immediately went outside to look for the jay with the screwed-up wing. She (pretty sure it was a girl) was still there, but that was the last time I ever saw her. She disappeared after that and I never saw her again. I feel that they probably killed her. (There was an episode about them killing a bluejay that Mr Leahy liked, so I guess they thought they would do the same thing to me.) You don’t have to believe this but I’m pretty sure it’s true because I got suspended from twatter right after I said (to “the trailer park boys”) that they had earned a curse from me and I said that if I saw any of their ugly faces they were risking getting popped. That made them really angry and I got suspended.
So I walked out onto my deck, scaring the jay away and walked over to the feeder. Turns out there was a sparrow who had its leg caught and was unable to fly away and the jay was pecking at it, trying to kill it. I got the sparrow's leg unstuck but it was broken but the bird still flew away.
I know they’re not nice. I like spiders, too.
I just want to add that if the jay (or any wild animal) is being a pest and causing trouble on your place, then you should probably shoot it - at least you’re within your rights to do so. But if you were to come onto my property and shoot the jays here, naturally that would not be okay. I know you would never do that! (And you know, you could make a great yard decoration out of the dead jays. That might keep the live ones away!)
I tried but the feral cats ate them.
I had a feral yellow female cat that lived under the deck of the house across the street. I used to feed it but she would never come to the dish when I was there, she would always wait in the distance until I went inside.
Whenever I would shoot the English sparrows under my bird feeders, the cat, who would always be hiding in the bushes of my backyard neighbor, would come rushing out and pick up the dead sparrow and take off to eat it. She was my Retriever Cat.
Over the course of two years, she had three litters of three kittens each that eventually would disappear. I don't know whatever happened to them, I often think a coyote may have gotten them even tho I've never seen it but I think I recognized its tracks in the snow in my front yard several times.
As for the female, she just disappeared last year too.
For the record, I've tried several times to trap her and take her to get neutered but she never fell for the trap.
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