The flock is led on flights daily, weather permitting, building their strength and endurance for the autumn migration. When the time comes, the birds follow the ultralight aircraft, as they would their parents, on a pre-determined route south. The structure of a flock is an important factor that we consider when trying to condition birds to follow our aircraft. This is true about every social species, including humans. In the avian world, the structure is established by aggressive behaviour.
Larger birds monopolize the food source leaving others to fend for themselves.
This is nature's way of ensuring the survival of the strongest and it also applies when the birds are airborne. The most aggressive and hardiest bird takes the lead or point position. With each down-beat of that bird's wings, air is forced out and rolls off the wingtip, creating a vortex much like the wake behind a boat. The other birds can sense this nuance in the air and surf on it, making the job of flying slightly easier. Each bird in order adds to the wake, assisting the birds behind, from strongest to weakest and creating one cadence, one flock.