43 thoughts on “Eagle 1, Drone 0”

  1. They are counting the total number of loops the, um video format has gone through in total. It shows when I mouse over the image.

    How do they know? Did they add something sneaky or are GIFs normally served continuously from the server.

  2. I imagine the propellers could pack quite a wallop. It could cause injury for sure if it hit the eye, but I suspect the plumage is pretty tough.

    1. A book I read many years ago (“Structures ; or, why things don’t fall down”, J E Gordon, most recent edition I can find is 2003, but I think the original dates back to the mid-60s. 1960s, not 18,60s.) commented appreciatively on the strength to weight ratio of contour (flight) feathers, and on their use in armour suits in mediaeval Japan. Gordon made good arguments over the strength of feathers (due to their combination of structures at levels form the macroscopic to the molecular – the main theme of his book). Which suggests to me that feathers are, as we know, really impressively tough.
      That would normally be a good enough citation for me. Unfortunately with the exception of one citation from the well-informed Pat Shipton (which I wouldn’t be surprised to find traces back to Gordon), I can’t find another mention of Japanese suits of armour made of feathers. Which leaves me a little uncomfortable.
      Oh, hang on … another mention, but for “Polynesians” ; and another referring to “Mexicans” (presumably Aztecs, Mayans and the like. Though it’s not clear if this was 2pure” feather armour, or in combination with quilted cotton. It’s still a bit “iffy” though.

      1. I have that book! One of the coolest stories is the guy who walked in with one of those paper honeycomb toys you see at the fair and wondered if it might help the war effort (WWII); he was a bit embarrassed because, while the structure was very strong, it wasn’t waterproof.

        The author’s eyes lit up and said they could make it waterproof by soaking it in some resin.

        This is a great book.

        1. Indeed a great book. I learned a huge amount from it. It’s companion (predecessor) “The New Science of Strong Materials or Why You Don’t Fall Through the Floor” is well worth a read too.

          1. I’ve got both of those! (The New Science of Strong Materials, and Structures).

            And ‘structures’ in that context covers everything from sailing ships to cathedrals to bias-cut dresses. And trees. And history (like the old English law that required every shipment of wine from Spain to be accompanied by a consignment of yew bowstaves IIRC).

            Along with ‘The Blind Watchmaker’ I’d nominate them as the best non-fiction writing I’ve ever come across. So clearly written that they make the technical concepts easy to follow, and with a gift for an intriguing phrase that makes you want to read more.

            cr

          2. They are pretty damned good. I’d forgotten about the dresses – my copies went into the charity shop pile two house-moves ago.

      2. I would think feathers would make excellent armour against cutting weapons (swords). Light, strong and bulky. Possibly less so against arrows unless the feathers were woven together in some way.

        Similar to the felt armour which was used by footsoldiers in the Crusades (not sure if I got that from J E Gordon or Terry Jones*). The fibres in felt will wrap around the sharp edge of a sword or the point of an arrow. Anyone who’s tried to cut felt with scissors will appreciate how it works.

        cr

        *Terry Jones the Python and historian, not the loony pastor.

        2. I do agree that the logic Gordon expressed is sound. It’s just nagging that I struggle to find other reporting of the materials. Given the recent post on replication in science, that does nag at me.

      3. When I caught a pigeon several years ago what struck me was how hard its body felt. Like I was holding a solid piece of rigid plastic. It took me by surprise since I was expecting something softer and squishier.

        1. Doing a little searching, I learned the feather rachis or main stem made of karatin structured in layers for strength and rigidity. It is hollow for lightness. The barbs coming off the rachis has many small scale structures that link them together into a web which is strong, light and waterproof. The magic of natural selection.
          https://goo.gl/nGHlSu

        2. If you’re referring ot the torso, there IS a lot of stiffening there. It’s needed to stand the loads imposed by the flight muscles.

      1. I worry the props could cause injury to raptors’ toes and ankles. Those could be debilitating, and if they got infected, all the worse.
        Perhaps the birds actually see and think quickly enough to appreciate and work around the moving blades. Does anyone, here, know?

        1. Damage potential from drones was tested on a recent episode of mythbusters. The conclusions they reached, the typical consumer type drones have props that are intentionally designed to be non-damaging and flex easily when they hit something.

          Larger more powerful custom made / special purpose drones can often have blades that are stiffer and that can cause serious damage, at least on the extreme end.

          Their testing consisted of running various drones into a human facsimile they had constructed out of modified ballistics gel to have the same mechanical properties as human tissues. Specifically they were attempting to cut the facsimile’s throat. None of the ones they tested caused any serious damage, no breaking of the skin and no breaking of the arteries/veins below the skin, until they finally tested a very large movie production camera carrying drone they had custom made. That one sliced deeply enough to sever the jugular.

          1. First…remember that birds are a lot more fragile than humans.

            Second…I’d love to see a plot of drone weight and the force of the prop strike. I’ll bet you a cup of coffee that’s the primary determining factor.

            Indeed, I’ll bet you another cup of coffee that you could come up with a tidy equation that relates the weight of the drone and the vertebrate being subjected to a prop strike to determine relative damage to each. The heavier the drone in relation to the vertebrate, the greater the chances for damage.

            b&

      2. The material properties of the stationary propellers is irrelevant. When not in operation, the cutting part of a weed whacker is just a small piece of nylon string, not all that different from heavy-duty fishing line.

        In the case of a drone, its weight and airspeed are going to be the dominating factors in the force exerted by a blade strike. Remember Newton: the blades are exerting a force on the air equal to the weight of the drone, plus whatever else is needed to overcome drag and all the other equations of aerodynamics. That translates into some impressive kinetic energy in the rotation of the blades, especially for heavier and faster models.

        b&

        1. It all depends on the size of the drone. I work with small camera drones pretty regularly and they’re smaller and less substantial than I think most people would realize. I don’t know how much force is actually generated as I know neither the exact mass nor the rotation speed of the props. But I can tell you that I’ve clipped myself with the props from a drone made for GoPro type cameras and I got a very minor abrasion.
          Regardless though, I think it’s probably good practice to avoid Raptors when piloting a drone. It may injure the bird and all evidence from the video suggests it will smash the drone right on up.

  5. I can’t tell just how far away the bird is at the start, but it is just a speck flying straight at the drone. No threat display, no hesitation, just a head on attack.

    This bird may have been lucky to be unhurt. Others will not be. Let me guess, knowing the location of an endangered specimen will make it more likely operators will want to get video before they are all gone.

  7. In all fairness to the drone, it wasn’t really trying. I’m willing to bet we could arm it so that it could kick that eagle’s butt.

    1. Except that a) you’d probably destroy the drone in the process as well, and b) you’d have the Fish & Wildlife Service up your butt in a heartbeat.

  9. I just had a very, very interesting thought.

    I’ve already thought about trying to attract bats to my garden once I’ve got it going.

    …but…well, there’re various small raptors, such as Harris Hawks, who live in the region.

    What’re the chances that I could both practically and legally persuade one (or a pair!) to take up residence at my decidedly suburban abode? Is there any sort of habitat / nest box / whatever that they would find irresistibly inviting?

    b&

    1. I used to have a colony of pipistrelles (Pipistrellus pipistrellus, not sure which species) living in my house. They roosted behind the vertically hung tiles on the front of the second storey. They got in and out through a couple of tiny gaps left where tiles had been slightly dislodged. I once counted 24 leave in 20 minutes one fine evening. Sadly, they left after a few years for no obvious reason. Apparently their motivation for where and why they roost is not understood.

      Although they no longer live with me, a few come back to hunt from time to time. The big attraction is the considerable insect population, which is in turn attracted to the many trees and patches of uncultivated ground in my garden. Since the bats feed at night, they do not interact with the many local Common Buzzards (Buteo buteo), so perhaps your Harris Hawks would not be a problem. I suspect that, unfortunately, the open country that attracts Harris Hawks might not support enough insects for bats, although that could differ, depending on the species.

      1. Thanks! Here’s hoping your bats return someday.

        I’ve seen both bats and raptors in the neighborhood, so I’ll definitely plan on doing some more investigation.

        b&

  10. Wow! That eagle just came out of nowhere. Even when you know exactly where it’s going to appear, it’s almost impossible to see before the last few frames. I can see how they can knock off their prey so successfully.

    cr

    1. Yes, on repeated viewings, I can just make it out coming in low over the treetops. It has such a slim profile from the front that it is nearly invisible, and it’s moving fast!

      1. Also, it seems to me that it very intentionally dips below the drone just enough to not be silhouetted against the sky. Is that a coincidence or ingrained behavior?

          1. I don’t think the eagle is going to have much awareness of the propellers. However, remaining below the horizon is going to offer superb visual cover, as you can see yourself. Above the horizon, the eagle will be very clearly silhouetted and easy to see and follow. Below the horizon, and the bird will get lost in the general clutter of the background. Indeed, a rapidly-approaching bird might not look very different at all from the gentle swaying of a tree branch in the wind — at least, not until the final several meters, at which point the closing speed of the bird leaves insufficient time for recognition and reaction.

            Picture it in your mind. A couple hundred meters away, the bird is smaller than a finger at arm’s length. An hundred meters away, the bird is still smaller than a finger at arm’s length. Fifty meters…still smaller than a finger at arm’s length. Twenty meters and it’s finally about the size of a finger at arm’s length…and in no more than a second of time it’ll cover that final distance and hit its target.

            b&

          2. Yes, I noticed that, too. But, for the eagle to do it with any accuracy, it would have to judge where it is in the visual field of the prey compared with the horizon behind it. Very hard or impossible to do. I’m guessing though that keeping the prey just above the horizon ahead would be a near enough approximation in most cases.

            cr

  11. Even from the brief look at the eagle, it is certainly a Wedge-tailed Eagle (Aquila Audax). They are the biggest eagle in Australia, with a wingspan of rather more than 2m (7ft), and weighing in at over 5kg. They don’t mess about when they attack prey either. They will take lambs quite easily, and even kangaroos are not immune – two months ago I saw a pair of wedgies feeding on an almost full grown female Eastern Grey Kangaroo that they had just killed.

  12. So far I can’t find any reports of wounded raptors from these sorts of encounters. Even without direct injury, eagles and hawks are being harassed by drones which are taken to be competitors or threats. There’s only so much of this bullcrap they’ll be able to take!

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