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](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2021/08/080921_jb_bird-feathers_feat.jpg?fit=1030%2C580&ssl=1)
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