A catastrophic return...
Part 1 used the zombie flick structure but featured stock material and lame isometric 3D renders of birds. This is also true of Part 2. It has more ambition, skin and explosive birds than its predecessor. It is made clear at some point in the plot that industrious people and rightists are to vultures and eagles what promiscuous teenagers on drugs are to supernatural serial killers.
Though Part 2 is no better than Part 1, some aspects of the production were cranked up a notch. The effects and action scenes are more elaborate. We get more people dancing funny. The thin mythology expands but drills itself with plot holes as it goes. We get topless nudity and another coitus interruptus at the halfway mark; the only window dedicated to an arc before or after the trigger event.
We’re now dealing with full-on zombie assailers. Characters return, including the manic preachy tree-hugger; a convenient plot device puppet who provides verbally what the author couldn’t convey with skills and experience. He was presumably too busy, then, planning montages of people walking in slow motion to the sound of eurodance instead of instigating a paced procedural and meaningful dialog.