Spatial and non-spatial actions of Polish groups

For locally compact groups all actions on a standard measure algebra have a spatial realization. For many Polish groups this is no longer the case. However, we show here that for non-archimedean Polish groups all measure algebra actions do have spatial realizations. In the other direction we show that an action of a Polish group is whirly ('ergodic at the identity') if and only if it admits no spatial factors and that all actions of a Levy group are whirly. We also show that in the Polish group Aut (X, X, mu), for the generic automorphism T the action of the subgroup A(T) = cls {T-n : n is an element of Z} on the Lebesgue space (X, X, mu) is whirly.