After hearing these things for several day here are my observations...They search around hard. I honed into a single individual tonight as there were only two calling. This evening the deal goes like this, I hear one well to the north of the property, It makes two calls and moves about 100 yards, two calls and another ~100 yards , two calls and another ~100 yds. (to the south), two calls and another two call etc. etc. until it is almost beyond hearing distance in 7-8 stops because of the other non-Gigas cicadas.....But I'll be damn if the thing does not return to the north and does the straight line path again!...At least I think it is the same bug. I know that sounds strange but after several evenings and especially tonight, that is sure what seems to be going on. It only does this trip twice as far as I can tell....I am only hearing two this evening and one is more distant.