Amallard duck egg hatches and the first moving object it sees is a young girl. the duckling begins following the girl everywhere. what is this case of mistaken identity called?

This case of mistaken identity called imprinting. The best-known form of imprinting is filial imprinting, in which a young animal acquires several of its behavioral characteristics from its parent. It is most obvious in nidifugous birds, which imprint on their parents and then follow them around.

It's speed of rotation.