The Animal Allies Field Setup document says this for the Animal Conservation model:
ANIMAL CONSERVATION: .... Finally, rest the red axle on its stopper.
So, the axle piece starts up on the stopper. With normal operation of the model, it will fall off the stopper and into the position that will stop rotation of the model after the model has rotated to make a complete switch.
If the team requests, the referee would then reset the axle piece up on the stopper to allow further rotation. If your team is going to ask for this, I recommend telling the referee when you first get to the table for your match.
Virginia-DC FLL Referee Advisor