The silent flight of the owl

March 17, 2015 • 12:45 pm

I can think of no better demonstration of this adaptation than this video and microphones used to listen to bird flight. Two birds—a pigeon and falcon—make a ton of noise while flying, while the barn owl’s flight is inaudible. The pigeon makes more noise than the falcon, for there’s no advantage to a pigeon flying silently, while there’s probably a marginal advantage for the falcon to tone down its approach.  But owls hunt at night, when prey are keenly attuned to the sounds of danger, and so owls have developed a new weapon in the arms race.

How do owls do it? The key is their uniquely serrated wing feathers, which you can read about here.

From the BBC show Super Powered Owls (sadly, you can watch it at the site only if you’re in the UK).

27 thoughts on “The silent flight of the owl

  1. I saw this on TV sometime in the past month or so, and thoroughly enjoyed it. An amazing process, evolution is, and its results are so often so beautiful in form and function.

      1. Fourth word: hearing. That explains their head shape, which is shared by Northern Harriers. My B*rder C*llie, Deets, also has acute hearing that enables him to catch voles and mice.

  2. See, this is why we should fear owls. They can be swooping up on you from behind right now and you will never hear it.

    1. You can stay safe by only going out in the rain. 🙂 Evidently one of the downsides of those soundless feathers is that they get waterlogged very easily.

  3. That’s really incredible. I’ve worked in Film/TV production for a long time, I used to work in radio and I’ve done voice-overs in several recording studios before. It is AMAZING that the Barn Owl can fly that close to those mics and not produce a larger waveform than that. I’ve had to wait a few minutes to record things in the studio before because there was a fire engine with its sirens on three blocks away.

    1. Convergent evolution, but under what selection pressure?
      Given that it’s the Stooges, I’d suspect aggressive mimicry. Not sure if the woop-woop-woop is supposed to be annoying pigeons, predators of pigeons, or anyone who’s ever nearly stepped on a pigeon, but it probably does all that.

  4. The PBS program revealed that owl night vision is twice as good as humans–kinda meager when cats’ night vision is reputed to be 6x of humans Both are amazing,stealthy nocturnal predators

  5. This is why any symphony price titled, “The Flight of the Owl” would be horrible. Like the audio equivalent of that Seagull movie.

  6. There is in Australia a pigeon which has utilized the noise generated by its modified wing-feathers to generate an alarm “call”.

    “Birds have a variety of alarm calls that warn other members of the flock about impending danger. But for some birds, the very act of taking off is enough to sound the alarm. Mae Hingee and Robert Magrath from the Australian National University have found that crested pigeons have modified wing feathers that produce distinct whistles when the birds take off quickly and steeply. That’s exactly the sort of flight that they undertake when they’re alarmed, and other pigeons treat the resulting whistles as cues to take to the skies themselves.”

    http://phenomena.nationalgeographic.com/2009/09/02/sound-the-alarm-crested-pigeons-give-off-warning-whistles-simply-by-taking-off/

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