  Let $X$ be a compact Riemann surface of genus $g \geq 2$, and let $D \subset
X$ be a fixed finite subset. Let $\mathcal{M}(r,d,\alpha)$ denote the moduli
space of stable parabolic $G$-bundles (where $G$ is a complex orthogonal or
symplectic group) of rank $r$, degree $d$ and weight type $\alpha$ over $X$.
Hitchin discovered that the cotangent bundle of the moduli space of stable
bundles on an algebraic curve is an algebraically completely integrable system
fibered, over a space of invariant polynomials, either by a Jacobian or a Prym
variety of spectral curves. In this paper we study the Hitchin fibers for
$\mathcal{M}(r,d,\alpha)$.
