  Transition decay widths by one-pion emissions for excited heavy-baryons with
a single heavy (charm and bottom) quark are investigated by following the
heavy-quark symmetry and its breaking effects at ${\cal O}(1/M)$ for a
heavy-baryon mass $M$. Based on the heavy-baryon effective theory, interaction
Lagrangian for the heavy baryons with axial-vector current induced by a pion is
constructed. It is presented that the transition decay widths up to ${\cal
O}(1/M)$ in several channels are constrained. The results will be useful in
experimental study of excited heavy-baryons.
