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A friend of mine made this photo on Mallorca of a overhead power line.

aviation obstruction marker

In my opinion the spirals are aviation obstruction markers. Any different information?

Uwe
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  • I would have thought the trees were enough to put-off any low flying aircraft. – Andy aka Sep 03 '22 at 10:49
  • Another question about mysterious devices on overhead power lines: https://electronics.stackexchange.com/q/253607 – pipe Sep 03 '22 at 19:26

1 Answers1

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They are bird-flight-diverters: -

enter image description here

Image taken from Wire Marking Results in a Small but Significant Reduction in Avian Mortality at Power Lines: A BACI Designed Study. Other types of bird flight diverters: -

enter image description here

Image from here.

Andy aka
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    wow, solid research there, Andy! – Marcus Müller Sep 03 '22 at 11:12
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    @MarcusMüller I'm a bit of a [twitcher](https://www.birdspot.co.uk/bird-watching-for-beginners/what-is-a-twitcher) so I've heard about these before especially on flight paths heading north from Africa crossing the Mediterranean (hence Majorca is a prime path). You sometimes get them in the UK where o/h wires run close to some nature reserves. – Andy aka Sep 03 '22 at 11:16
  • I'd also be interested if anyone could say what this is (in the picture): https://i.stack.imgur.com/osNPz.jpg <-- I'm (badly) guessing it's a moth/insect collector? – Andy aka Sep 03 '22 at 11:24
  • Love how that explanation is basically "twitching, that's like heroin", while, honestly, it's a hobby, and on a scale of hobbies, it's pretty – harmless? I guess? Sure, makes some folks go outside that others might avoid socializing with? – Marcus Müller Sep 03 '22 at 11:26
  • Do large birds like storks a stopover in Mallorca? – Uwe Sep 03 '22 at 11:27
  • @Andyaka yep, this looks like a pheromone trap that has a collection bucket underneath, probably to not only get rid, but also quantitatively observe pests. I've seen differently-shaped ones around here (Southwest Germany), let me try to dig up a picture. – Marcus Müller Sep 03 '22 at 11:28
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    nah sorry, don't have photos from that trip – Marcus Müller Sep 03 '22 at 11:30
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    @Uwe I think storks are a rarity in Majorca <-- they're not in North Africa either as far as I know. – Andy aka Sep 03 '22 at 11:34
  • They found much more carcasses of large birds with a big wing span than small birds with wing span smaller than conductor distance so I think it is plausible. – Uwe Sep 03 '22 at 13:42
  • Very close then: avian obstruction markers, not aviation obstruction markers. – davidbak Sep 04 '22 at 01:31