Saturday, 22 August 2009
Friday, 21 August 2009
More info and photos here. To be continued here.
Thursday, 20 August 2009
This Peacock was feeding upside down on a Buddleia showing its eyespotsThis intimidating display was described over a century ago and its effect on predators noted, but experimental support for its effects on the survival of the butterflies themselves was lacking until very recently. Adrian Vallin and collaborators tested the effect of eyespots, stridulation and both combined by modifying captive-reared peacock butterflies experimentally. They removed the eyespots by painting over them with a black marker pen and removed the stridulation ability of the butterflies by cutting out the veins responsible for making the hissing noise. They also tested the effect of the combined factors, that is removing both the eyespots and the noise-making wing veins. Unmodified controls, and controls in which a similar area of wing was painted black without touching the eyespots or cut without affecting the ability to make noise were also tested (bottom row below).
Vallin, A., S. Jakobsson, J. Lind & C. Wiklund (2005) Prey survival by predator intimidation: an experimental study of peacock butterfly defence against blue tits. Proc. R. Soc. B. 272:1203-1207.