What do you think is happening here? Is this a landing or a hunt? These actions happen within seconds, so we have to be ready if we are planning to catch them in action. Patience is the key here along with gaining trust. Instead of approaching it, if you let the bird come near you, the chances of nailing the image sky rockets.
As we laid down, camera tucked to our eyes, this hunter swooped just in front of us, caught its prey and gobbled it. All these happened within a blink of an eye. These birds are not only agile in air, but also on land. I think the reason why they open their wings while approaching their prey is to confuse it. One more observation is to maintain proper balance in the middle of a hunt.