  A chain of magnetic impurities deposited on the surface of a superconductor
can form a topological Shiba band that supports Majorana zero modes and holds a
promise for topological quantum computing. Yet, most experiments scrutinizing
these zero modes rely on transport measurements, which only capture local
properties. Here we propose to leverage the intrinsic dynamics of the magnetic
impurities to access their non-local character. We use linear response theory
to determine the dynamics of the uniform magnonic mode in the presence of
external $ac$ magnetic fields and coupling the Shiba electrons. We demonstrate
that this mode, which spreads over the entire chain of atoms, becomes imprinted
with the parity of the ground state and, moreover, can discriminate between
Majorana and trivial zero modes located at the ends of the chain. Our approach
offers a non-invasive alternative to the scanning tunneling microscopy
techniques used to probe Majorana zero modes. Conversely, the magnons could
facilitate the manipulation of Majorana zero modes in topological Shiba chains.
