Who took over the outcast when Jonathan livingstone seagull vanished?

In Richard Bach's "Jonathan Livingston Seagull," after Jonathan vanishes, the outcast seagull is taken over by a new character named Fletcher Seagull. Fletcher, inspired by Jonathan's teachings and flying techniques, begins to embrace the idea of pursuing perfection in flight, continuing Jonathan's legacy. Through his experiences, he learns to break free from the constraints of conventional seagull behavior and seeks to achieve higher levels of flight and understanding.