Which mechanism prevents airflow stall at high angles of attack in soaring birds like eagles?

💡 Explanation

When birds fly at high angles of attack, the alula feather creates a leading-edge vortex due to boundary layer separation, re-energizing the airflow over the wing and delaying stall. Therefore, leading-edge vortex formation results, rather than low drag, reduced inertia, or turbulence manipulation which involve distinct aerodynamic principles.

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