Structural Blues

Bright blue colours in birds and insects is literally a trick of the light. These species don't produce a blue pigment, but due to microscopic scales or other physical surface arrangements for refracting and reflecting light, what the human eye sees is sparkling blues and greens. Because the colour is caused by the actual structure of the animal, this type of colour survives even in fossils.

Here are some local, living examples:

The chafer beetle Hoplia caerulia, photographed near Candes Saint Martin.

 A peacock at the Chateau de Rivau, near Chinon.

A male Adonis Blue Polyommatus bellargus on one of my butterfly survey transects.

 Fossils of this irridescent reed beetle Plateumaris sericea and other closely related species have been found in Japan. These rather lively ones were photographed in the Brenne.