As with the banded demoiselle is also in the blue wing-demoiselle a pronounced territorial behavior of sexually mature males. These days occupy territories that they defend against other males. The defense consists mostly in threatening gestures. For this they spread their wings and put them on display so clearly visible, there is also Drohflügen and in rare cases to air combat between rival males. Optimal areas correspond to the optimal nesting places for the females and are characterized by a normally increased flow and a suitable oviposition substrate in the potential breeding sites from. The size of the spots and their distance apart is the density of the population dependent as well as the occurrences of the water and may be between several meters and a few decimetres. Males who do not occupy spots can keep themselves in the vegetation on the shore and try to mate with fly to females or to fill vacant spots. Especially when only a few males are present, the territorial defense is very aggressive, with a higher number of competing male aggression but decreases significantly.