Males of C. diadema are not territorial; instead they patrol long routes by streams in southeastern Arizona. Certain stream segments are visited sporadically by many different males. Females rarely appear at water and receptive females are rarer still. Males capture receptive females in flight, copulate while perched for periods of about 2 hr, after which their mates are released to oviposit unguarded. The significance of the correlation between prolonged copulation and non-territorial patrolling, which occurs in this and other unrelated dragonflies, remains to be fully understood.