European bird eater wings

As you might know, to fly you have to catch lots of air under the wing (or at least a bit more than the amount above the wing) so that the air pressure is pushing you up and keeping you in the air. Well, when I saw a photo of a european bee eater, and it had an area in it's wing that did not have feathers.

So why is this gap here? Well one thought is that it might alow diferent parts of the wing to move up and down just like a planes flaps on it's wings. That would alow it too brake and use less energy when in flight.

Another thought is it might be like those flaps on parachutes. That would stop it's wings getting ripped of when it goes for a dive or goes at high speed. That way if the first and the second ideas are correct the european bee eater could go at alot higher speeds than other birds.

My last idea is that maby the bird was just born that way and it's not normal, the bird might have been attaked or hit a tree branch or last of all it wight be there to make it's wings wider.

Thank you.

european bee eater with gap

european bee eater with gap

european bee eater without gap

parachute

aironautics diagrame