EPOW - Ecology Picture of the Week

Eye Spotted a Butterfly

Unidentified Butterfly
Seti River, Nepal

Explanation:  On a raft trip down the Seti River in Nepal, we put ashore at a camp site.  There, I ... spotted a butterfly.  Or, more precisely, Eye Spotted a Butterfly.

By that, I mean (with a bad pun, apologies), the butterfly I spotted had eye spots.  
On the wings.
   

Why?  Well, butterflies with wing eye-spots serve as a predator deterrent.  Predators see the spots and, assumedly, assume it is a larger predator that they should avoid.  Thus, they leave the butterfly intact.  And not attacked.

And, equally interesting, such eyespots in some butterfly species also serve as signals during courtship (see Kodandaramaiah 2011).  This was likely a secondary function that evolved after the anti-predator one.  

One interesting point about this particular butterfly species is that its eyespots were on both the outside and inside of the wings.  So whether the butterfly was perched with wings closed, as in the above photo, or flying or just landed with wings open, as in the photo below, it still exhibited big staring eyes.  I don't know if this is common, or what percent of eyespot-bearing butterflies have this adaptation. 

  
  
Information:
     Kodandaramaiah, U.  2011.  The evolutionary significance of butterfly eyespots.  Behavioral Ecology 22(6):1264-1271.