For growth rate a=0.05, one has monotone growth:
This is confirmed by fractional iteration:

As already shown, a=0.95 leads to oscillation, and the fractional oscillations are much larger than the integer ones:

At a=1.32, things get pretty irregular; fractional iteration shows what "really lies in between":

At a=1.4, one seems to enter the chaotic realm, while the fractional chaos looks more interesting: