What is one of the primary reasons the Harrier's slow, low flight is effective for ambushing prey?

Answer

A high-speed approach would likely blow the prey away

The immediate vertical drop from a slow cruise is more effective for ambushing prey hidden in grass than a high-speed approach, which risks blowing the prey away.

What is one of the primary reasons the Harrier's slow, low flight is effective for ambushing prey?
birdanimalspeedflightHarrier