Note the man, probably the unit commander, standing close to the tree trunk. The column probably was moving on a path which kept them close to whatever cover was available. Actual bivouac was never in the open. When aircraft were heard, all troops simply froze in position. As it had against the Chinese Nationalist Air Forces this simple tactic was effective enough to conceal their movement from our air observers, who were looking for area-disturbance marking assembly points, or at least for movement.
