It is therefore not any more unlikely that partner loyalty may be a matter of the degree of the partners "fitting together" and a change of the mate a matter of choice by both sexes. This is supported by our observations in Hamburg, where a single adult crane tried for a whole spring season to win a mate bound with another male, however without success. Together with behaviour observations made by me over years in Hamburg, indicating a higher degree of cognitive abilities and even some degree of awareness, these results may motivate further deeper research both in field as with captive cranes. They do at least demand more respect for them as subjects (individuals) rather than objects.
In addition, the different method of observing the birds - by ear rather than by eye - led the author to listen and record also other vocal expressions of various crane species.
Such recordings and their interpretations are in use in the important attempt of reintroducing Whooping Cranes in Wisconsin and teaching them to migrate for wintering in Florida. Replays of the digital recording of wild Whooping cranes expressions are used to "communicate" with the chicks to be raised and trained to follow ultralight airplanes. Three successful migrations (one final experimental with sandhill cranes and two real with isolation-reared Whooping cranes) have been made.
Erste Bestimmungsversuche wurden unter anderem auch mit Schwarzspechten unternommen.