  In their comment on our work (ArXiv:1912.07056v1), Cavagna \textit{et al.}
raise several interesting points on the phenomenology of flocks of birds, and
conduct additional data analysis to back up their points. In particular, they
question the existence of rigid body rotations in flocks of birds. In this
reply, we first clarify the notions of rigid body rotations, and of rigidity
itself. Then, we justify why we believe that it is legitimate to wonder about
their importance when studying the spatial correlations between speeds in
flocks of birds.
