====== Zebra stripes ======

>__"Despite over a century of interest, the function of zebra stripes has never been examined systematically."__

The quote is from an extensive 2014  [[http://www.nature.com/ncomms/2014/140401/ncomms4535/full/ncomms4535.html|study]] published in //Nature Communications//. The study examined the five prominent theories regarding the zebra stripes question. They are:

  * 1) as a form of visual crypsis (camouflage) - probably matching a woodland background\\   
  * 2) disrupting predatory attack by visual-dazzling effects\\ 
  * 3) reducing thermal load\\ 
  * 4) having a social function.\\ 
  * 5) avoiding ectoparasite attack\\

The 2014 research team //excluded// :

Hypotheses 1 & 2) //"Despite the popularity of various sorts of confusion hypotheses, our data provide little support for this idea."//

Hypothesis 3) //"Heat management does not appear as a driver for equid stripes"//

Hypothesis 4) //"A social function cannot explain striping in equids either"//

Leaving hypothesis 5) which they suggested //"lend(s) strong ecological support for striping being an adaptation to avoid biting flies."//

However, a previous (2002)__ BROKEN-LINK:[[http://onlinelibrary.wiley.com/doi/10.1046/j.1365-2907.2002.00108.x/full| study]]LINK-BROKEN__ (in //Mammal Review,// Volume 32, Issue 4) had pointed out that the fly-avoidance idea was //"[...] the only hypothesis that has been tested experimentally, and the results of these tests are inconclusive."//\\  And further, the [[https://en.wikipedia.org/wiki/Mountain_zebra|Mountain Zebra]]  which has the most prominent and defined stripes, does //not// live in areas prone to biting insects.\\  Another [[https://royalsocietypublishing.org/doi/abs/10.1098/rspb.2009.2202|experimental study]] (in: //Proceedings of the Royal Society, B//) performed in 2009 (with horses) showed that the most advantageous colour for insect-avoidance was white only.\\  A 2019 study found that horseflies preferred [[https://royalsocietypublishing.org/doi/10.1098/rsos.181325#d3e1754|dark colours]] over stripes.

(//Note:// There are many other, less mainstream ideas, for example __ BROKEN-LINK:[[http://www.jstor.org/stable/23736929?seq=1#page_scan_tab_contents|another theory]]LINK-BROKEN__ (in:  //Annales Zoologici Fennici// Vol. 44, No.5) was put forward in 2007 - that the stripes might operate as //"an amplifier of the individual's escape potential."//)

----

//Further reading://

 [[http://www.press.uchicago.edu/ucp/books/book/chicago/Z/bo24838630.html|'Zebra Stripes']] by Tim Caro, University of Chicago Press, 2016

[[https://royalsocietypublishing.org/doi/10.1098/rsos.140452|How the zebra got its stripes: a problem with too many solutions]] //Royal Society Open Science//, 2015