Possible Clues:

• A sea bird is in former surroundings every second
• Every other way to change the end to ante, for instance
• The way to change a ten in every other way
• First the one, then the other
• Every other way to change to start with
• That could be one way to make a ten of this, or every other one
• Every other tent a real disaster
• Take turns later maybe - neat solution
• Showing wings either side of seabird go back and forth
• Perhaps to change it to a ten in every other way