Bioacoustic methods have been studied in the past by many groups also with the goal to identify and recognise individual birds. Such attempts have been devoted to loons, ... and Woodcock. but according to literature, there are no broader long term practical projects attempting to monitor birds individually.
The "unison call" is a strong, far carrying duet call presented only by paired cranes e.g. in the morning, or when defending or marking their territory, when meeting each other and after copulation. In most crane species the male exhibits a longer (about 0.5 sec) lower pitch call, which the female answers (sometimes beginning during the male's call) with two to four short, high pitch calls. No hints were given as to the question if any individual characteristics had been found.