 The presumed function of the identity call, which is regularly used during the non-breeding season, is contact with the partner across their territory.The variable tune of the identity note and lengths of rests, one to three times the note's value in each call, is repeated in turn by their mate after several seconds—the communication continues for a few minutes and is re-established around every half hour.During breeding in captive pairs, the tone of the male's call is reported to be higher pitched and the tone of the female quavering.