bild

Owl butterfly wing. Macrophotograph of an eyespot on the wing of an owl butterfly (Caligo idomeneus). Butterfly wings are covered in coloured scales which create patterns on the wing. The scales may be lost without hindering the butterfly in flight. The patterns are useful as a threat rather than as a means of camouflage. This butterfly is native to South America. (KEYSTONE/SCIENCE PHOTO LIBRARY/DR KEITH WHEELER)