Such research would be expensive and time-consuming, requiring long-term monitoring of substantial numbers of banded individuals from several selected populations.
Cette recherche serait coÃ»teuse et longue, puisqu'il faudrait surveiller Ã long terme un nombre considÃ©rable d'individus baguÃ©s appartenant Ã plusieurs populations sÃ©lectionnÃ©es.