  In this work, we examine the effect of shear and bulk viscosities on elliptic
flow by taking a realistic parameterization of the shear and bulk viscous
coefficients, $\eta$ and $\zeta$, and their respective relaxation times,
$\tau_{\pi}$ and $\tau_{\Pi}$. We argue that the behaviors close to ideal fluid
observed at RHIC energies may be related to non-trivial temperature dependence
of these transport coefficients.
