Sunbirds’ dazzling feathers are hot, in both senses of the word

A metallic sheen attracts mates but warms easily, possibly making it harder to keep cool

male greater double-collared sunbird

The iridescent green and blue feathers of a male greater double-collared sunbird (Cinnyris afer) reflect light and also absorb it, heating up in the sunlight.

Svana Rogalla

For sunbirds, all that shimmers is piping hot.