Kapitel 7: Reumés
Result (2): Banded wild birds
T
heoretically, there may still remain some doubts whether wild birds would display a stable and differentiated enough in frequency and frequency pattern to be used for individual characterisation and recognition. Some pure scientists may only accept results where banded birds are involved because they may argue that spectra of different calls which are assigned to belong to the same pair could only show comparable features by accident, and that a final proof can only be based on calls of banded birds.
Before reporting on such experiments attempted in the last years as well, it should be reminded that it was also possible to record, analyse and assign captive crane pairs (especially Whooping Cranes, but several other species, too) with this technique, and that spectra of different calls of the same pairs show a comparable degree of similarity as do calls expressed by pairs in the wild which can be assumed to be the same as they live and call in the same territory.
However, various calls from banded cranes whereby the birds were visually observed during the calling and recording, are preferred to eliminate remaining doubts. The following banded cranes have been recorded (figs 8 - 12 a, b): //Beringung bennen//
