These young birds have passed the first step. They are chasing the adult for food, or the hope of food.
The fun part is later on when the adult starts to be evasive. That’s when they learn to twist and turn in mid flight.
Sometimes the adult will slow down and let them get close.
Unfortunately this training is dowe in and around a rookery meaning trees, bushes, and water. There is not a lot of open space to focus and catch them all in flight.