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The insane biology of the dragonfly (2021) [video]
- apienx 4y agoSpecialization is for insects. -- R. H.
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- jacquesm 4y agoWhat a great video. Dragonflies are relatively uncommon where I live now but in Canada they were quite common and some of those were at the upper range of the size of the ones that are still alive today. Imagine those 70 cm wingspan pre-historical versions, that must have been a sight to watch. They're as closely evolved to what is the biological equivalent to an attack helicopter as possible. Seeing them hunt will make you very happy that you're not born as a small insect. I've found more than one caught on the inside of a large barn that was open on one side, they'd keep on banging into the windows on the closed side because that was the most lit up part of the barn, for all their technical advantages and various optics they are not able to fly back out of a box that they fly themselves into even though it is perfectly open on one side. They will just keep on trying until they exhaust themselves, then you can pick them up carefully and release them again outside the enclosure, hopefully to catch a meal soon with the remaining bit of energy after a rest.
- LargoLasskhyfv 4y agoThey are curious too, or territorial. While bicycling through the forest in my youth, there was a small lake beneath a swampy area next to a small farm with cows and horses. Also many fawns/deer not far away. They really thrived there, bodies large as a fat cigar. Every time I sped by that lake, they escorted me for a while. Going about 40 to 50 kph. Effortless. Like on rails, but almost instantly 'hopping' from one rail to another. Up, down, more near to my head, back away. For maybe 500 meters. Then turning back almost on the spot. Their checkerboard patterns glittering. Very strange magic :-)
- ehnto 4y agoWe are having a boom here, there are thousands of them. They are keeping the mosquitos away. My lasting impression of them is from a forest walk a decade ago, where I was surrounded by hundreds of them, and I found them super clumsy. Every step I took I spooked a couple, and they would fly as fast as possible in a fixed direction, which resulted in dozens of them slamming into trees and knocking themselves out with an audible thwack.
- bmitc 4y agoIt’s interesting to think that there are no boxes in nature, especially boxes with lights or transparent windows. So while it seems initially weird dragonflies and other insects really struggle with lights, windows, and human attributes, I suppose it makes evolutionary sense. They used to only have two “north stars”, the Sun and the Moon, and no boxes. I wonder if there is any evidence for noticeable adjustments in insect navigation.
- setr 4y agoa box is any closed container — a cave, a hole in a tree, a dense forest Though the light I think would almost always lead the way out in these cases
- KineticLensman 4y ago> So while it seems initially weird dragonflies and other insects really struggle with lights Some birds also get confused by glass, although they do seem better able to consider an alternative (e.g. an open door) when one presents itself. My dataset is the small number that sometimes get into my shed when the door is open. Tangential glass/bird related story time. I occasionally see small birds pecking at their reflection in glass. I once saw a Long-Tailed Tit pecking at my shed window and watched it for a few seconds. And then it went one way, and the reflection went the other! That's when I realised that there was a bird on the inside as well. Cue rescue mission (opening the shed door).
- dieselgate 4y agoIt's cool to see examples comparing the agility of a 4 winged insect compared to 2 wing/diptera. Think about this sometimes when seeing human (2 leg) running/playing with a dog (4 leg). Dogs and other 4 leggers can make some insane lateral movements
- adrian_b 4y agoDragonflies have very different wing muscles in comparison with almost all other 4 winged insects, which allow them to move each wing independently and with great precision. Except for dragonflies, all the other insects which are agile fliers achieve their agility by using only 2 wings, because 4 wings that are not exquisitely controlled are a hindrance, not an asset. This is done by either not using one wing pair for flying, as in flies, or by having a mechanical linkage between the 2 wing pairs, making them work like a single pair, as in wasps or hawk moths. While most flies are no match for a dragonfly, there is a fly family, the robber flies, which look like dragonflies with 2 wings (i.e. they have big heads with big eyes and a long narrow body, though not as long and narrow as most of the less stocky dragonflies). The robber flies routinely eat dragonflies, catching them easily during the flight.
- personjerry 4y agoI played Dune 2000 as a kid and remember vividly the four-winged ornithopters modeled after dragonfly wings. I wonder if it's practical to build such an aircraft as an improvement on helicopters?
- mac01021 4y agoThe wings on the thopters described in the novel by Frank Herbert were more bird-like than insect-like. I don't know which type, if either, will be more practical to build as materials technology improves.
- JKCalhoun 4y agoPlenty of people have tried. Replacing helicopters though? It looks like ornithopters don't scale well. This guy in Japan posts his various experiments in ornithopteria. https://youtu.be/dHIF_2OsA_8 https://youtu.be/dHIF_2OsA_8
- stevenwoo 4y agoI remember going through a fascination with rubber band powered paper/balsa ones in childhood, they were very light and fragile. People tried to scale it at the time helicopters were first practical https://ornithopter.org/history.rubber.shtml https://ornithopter.org/history.rubber.shtml
- SigmundA 4y agoProbably not, in the new movie they where very dragonfly like too and looked quite realistic, but man the engineering a materials science to make that practical, not sure: https://www.youtube.com/watch?v=qYPuhItRqVk https://www.youtube.com/watch?v=qYPuhItRqVk
- mcphage 4y agoThe video's description of their brain and hunting behavior reminds me of PID controllers—making predictions about where the prey should be, adjusting their head to target it, and using the error in their expectations to update their predictions.
- eternalban 4y agoWe humans have really lucked out in the evolutionary casino on this planet. We could have been living in a horror show, with giant flying predators with equivalent intelligence.
- artificialLimbs 4y agoVery cool. I made a video a few months ago about how to befriend dragonflies. They'll let you pet them if you have the right approach. Message if you'd like to see. Not trying to spam youtube vid/self promote.
- dv35z 4y agoPlease share - would love to see that.
- artificialLimbs 4y agoEmailed you.
- thombat 4y agoPlease share more widely, i.e. paste the link - something on topic and of general interest isn't spam.
- artificialLimbs 4y agoWell alright then. Super not proud of the video quality/editing, btw. =D "Good stuff" is around 8:40 if you want to skip ahead. https://www.youtube.com/watch?v=70utrQvHGd0 https://www.youtube.com/watch?v=70utrQvHGd0
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