  Let F/Q be a totally real field extension of degree g and let D be a definite
quaternion algebra with center F. Fix an odd prime p which is unramified in F
and D. We produce weight shiftings between (mod p) automorphic forms on the
multiplicative group of D having fixed level. When the starting weight does not
contain any (2,...,2)-block, we obtain these shiftings via maps induced in
cohomology by intertwining operators acting on F_{p}-representations of
GL(2,O_{F}/pO_{F}). Shiftings by (p-1,...,p-1) for weights containing
(2,...,2)-blocks are obtained following the methods of Edixhoven-Khare, as half
of our intertwining operators becomes trivial in this case.
