  We present evidence for the presence of a transition in the accretion
properties of radio-loud sources. For a sample of radio galaxies and radio-loud
quasars, selected based on their extended radio properties, the accretion rate
is estimated from the black hole mass and nuclear luminosity. The inferred
distribution is bimodal, with paucity of sources at accretion rates, in
Eddington units, of order ~ 10^{-2} - assuming a radiative efficiency of 10 per
cent - and possibly spanning one-two orders of magnitude. Selection biases are
unlikely to be responsible for such behavior; we discuss possible physical
explanations, including a fast transition to low accretion rates, a change in
the accretion mode/actual accretion rate/radiative efficiency, the lack of
stable disc solutions at intermediate accretion rates or the inefficiency of
the jet formation processes in geometrically thin flows. This transition might
be analogous to spectral states (and jet) transitions in black hole binary
systems.
