Âm thanh chia sẻ

This bird… flies where oxygen is barely enough to breathe. Higher than most planes fly. Where air is thin… and survival is unlikely. This is the bar-headed goose. And it crosses the Himalayas. At altitudes over 7,000 meters. So how does it survive? Its lungs are more efficient. Its blood carries oxygen better. Even in near-empty air. Every wingbeat is powerful. Every breath counts. It times its flight with favorable winds. Avoiding the worst resistance. While others stay low… th