[HN Gopher] Zebras of all stripes repel biting flies at close range
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       Zebras of all stripes repel biting flies at close range
        
       Author : jarenmf
       Score  : 80 points
       Date   : 2022-11-05 16:26 UTC (6 hours ago)
        
 (HTM) web link (www.nature.com)
 (TXT) w3m dump (www.nature.com)
        
       | [deleted]
        
       | WalterBright wrote:
       | I wonder why outdoor apparel makers don't make zebra striped
       | clothing.
        
         | jabl wrote:
         | Good point. Maybe there's competition from alternative
         | patternings. Like camouflage type patterns for hunters /
         | preppers / military cosplayers. Or high-viz colors for people
         | who worry about safety wrt. various kinds of accidents. Or just
         | whatever the current per se meaningless trend colors are?
        
         | SoftTalker wrote:
         | Seems like I remember it being a short-lived trend in the
         | 1980s?
        
           | WalterBright wrote:
           | The idea isn't trendiness, it's to reduce the mosquito bites.
        
         | atdrummond wrote:
         | Zubaz?
        
       | bilsbie wrote:
       | My idea (consider this public domain / prior art if no one has
       | though of it)
       | 
       | We introduce tree frogs or perhaps geckos or chameleons to live
       | on cows. They would eat the flies and the body heat could
       | probably keep them warm year round.
       | 
       | They'd eventually breed themselves to adapt to the life cycle and
       | be self perpetuating.
        
         | osrec wrote:
         | Okay, but how would they live "on" cows? Just ride on a cow's
         | back? It may be more bothersome to the cow than a few flies!
        
       | protomyth wrote:
       | _Our findings confirm that zebra stripes repel biting flies under
       | naturalistic conditions and do so at close range_
       | 
       | Which has lead to suggestions to breed this into livestock. Which
       | will certainly change the landscape in US.
       | 
       | As I said before: _Somehow driving through South Dakota looking
       | out over a vast field of seaweed eating, zebra striped cows was
       | not the future I anticipated as a youth._
        
         | libertine wrote:
         | I have a question, due to the lack of diversity of food sources
         | for flies, wouldn't that pressure de evolution of flies that
         | ignore the stripes?
         | 
         | Maybe there would be a decline in population first, then a rise
         | of stripe seeing flies.
        
         | metadat wrote:
         | The flies might still hang around for a slice of pie.
        
           | justinpowers wrote:
           | Striped pie anyone?
        
         | BurningFrog wrote:
         | Or a new rural profession of Cow Painter springs up!
        
       | therusskiy wrote:
       | Zebra stripes are basically an adversarial pattern for Neural Net
       | in a fly's brain.
        
         | sandworm101 wrote:
         | Evolution is two-sided race. Insects breed/evolve much faster
         | than large mammals. One must wonder why they haven't evolved
         | the brainpower to overcome this trickery. The difficulty of
         | feeding on zebra must not be enough of an evolutionary pressure
         | ... until all the other animals start evolving stripes too.
        
           | metadat wrote:
           | That is a good question. Given the short lifespan of the
           | creatures, one hypothesis is their evolution is stuck in a
           | high-walled local maxima.
        
       | amelius wrote:
       | And at night?
        
       | gcanyon wrote:
       | "the source of the effect remains unexplained" They list several
       | candidate explanations, but miss one I came up with immediately:
       | maybe zebras are in some other way less attractive targets for
       | the flies -- their skin is thicker, their blood/fluids don't
       | taste as good, etc. -- and the stripes are simply a visual
       | indicator to the flies that they are zebras, and therefore less
       | desirable. This sort of trait has evolved poison frogs, insects,
       | and other plants and animals, so why not zebras?
        
         | Gys wrote:
         | Seems easy to test? Just paint a horse or cow and keep count of
         | the flies.
        
         | idlewords wrote:
         | This is mentioned in the paper, and you can find citations
         | there to previous experiments where the visual effect alone is
         | tested and demonstrated to be very strong. Whatever other
         | defenses a zebra has, it's been shown that flies really hate
         | those stripes.
        
         | gernb wrote:
         | maybe zebra skin has a different oder. They said they used
         | pelts.
        
         | aaron695 wrote:
        
       | lttlrck wrote:
       | I need zebra patterned socks.
        
       | bmitc wrote:
       | I recently learned this from BBC's _Life in Colour_ documentary.
       | It explained it, similar to the article (although the paper
       | really dances around this hypothesis), that the flies had a hard
       | time landing due to some visual weirdness from the stripes when
       | the flies are close up. They had a lot of close-up footage of
       | flies hovering above a zebra 's skin but seemingly confused on
       | how to land.
        
         | aeternum wrote:
         | Our eyes can also be confused by relatively simple patterns:
         | http://brainden.com/images/ricewave-big.gif
         | 
         | Intuitively, it does seem like stripes would make it more
         | difficult to achieve focus for a compound eye, similar to how
         | when looking through a chain-link fence or window screen it's
         | easy to focus the wrong plane due to the spaced repetition.
        
           | BolexNOLA wrote:
           | I'll never forgive Animal Collective for using this as an
           | album cover!
        
           | bmitc wrote:
           | Vision is weird. It's things like this that, in my opinion,
           | showcase the idea that our perception of reality is sculpted
           | by our physiobiology.
        
         | SoftTalker wrote:
         | I wonder why, over the long term, the flies did not adapt to
         | this.
        
           | miohtama wrote:
           | Maybe compound eyes have some inherit flaw that makes it
           | harder to process visual signal of stripes.
        
           | gcanyon wrote:
           | Or the short term -- flies have much shorter generations.
           | That doesn't guarantee faster evolution, but it helps.
        
             | jabl wrote:
             | Maybe the adaptation would require significantly more
             | advanced visual processing with attendant increase in
             | weight, size, and energy consumption, making it not worth
             | it?
        
       | manmal wrote:
       | I thought this has been common knowledge for decades.
        
         | Sharlin wrote:
         | Literally the FIRST two sentences in the abstract:
         | 
         | "The best-supported hypothesis for why zebras have stripes is
         | that stripes repel biting flies. While this effect is well-
         | established, the mechanism behind it remains elusive."
        
       | [deleted]
        
       | lifeisstillgood wrote:
       | That's fantastic. I so needed something that hit "I never knew
       | that" and "not remotely connected to tech and jobs and
       | mortgages".
       | 
       | Well done World for funding simple scientific questions - not
       | trying to fix the planet, just asking "why does _that_ happen ".
       | 
       | Marvellous
       | 
       | One (morbid) thought - I wonder if lions get bitten less when
       | heads down in a black and white carcass?
        
         | [deleted]
        
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