Transport measurements on thin films of NdNiO3 reveal a crossover to a regime of pronounced nonlinear conduction below the well-known metal-insulator transition temperature. Surprising evolution of the transport properties is observed at temperatures well below this transition, which appears consistent with a gradual formation of a gap in the hole-like Fermi surface of this strongly correlated system. A model of Landau-Zener breakdown fails to describe the I(V) characteristics at high temperatures, where Ohmic transport dominates, but becomes increasingly more appropriate as the temperature approaches 2 K.