Once the Golden Stinger Wasp had returned, Michael's energy storage was also filled to the brim.
Icarus and his mate ascended into the air. However, nobody was sitting on the Greater Eagles' backs. Instead, the Greater Eagles had become decoys for the guards of the border settlement.
By now, everyone should have been informed about the Greater Eagles, Michael, and the others. It made sense to travel quickly through the Savannah region on the Greater Eagles' back, but they were quickly exposed as well.
It was rare to find two Greater Eagles in the Savannah region, let alone that the Greater Eagles were headed to Beast Ranches, only to depart a few minutes later, leaving behind death and chaos.
Wherever they went, the Beast Ranches were destroyed at those locations. They were even present when the main settlement had been under attack. Therefore, it didn't require a genius to conclude that Michael was in control of the Greater Eagles.