How hummingbirds avoid overheating

Colourful footage, shot with a thermal camera, has revealed how hummingbirds avoid overheating as they beat their wings up to 70 times per second.

As this short clip shows, the birds have "windows" for heat loss around their eyes, shoulder joints, feet and legs.

This study, led by George Fox University in Oregon, US, is part of a Nasa-funded project to uncover the effects of climate change on the birds.

The results are published in the journal Royal Society Open Science.