 A ' corroboree ' ( from the word for a ceremonial meeting of Aboriginal Australians ) is a group display where birds converge on adjacent branches and simultaneously pose hunchbacked , giving wing @-@ waving and open @-@ bill displays and the yammer call . A corroboree occurs when birds meet after a change in the social environment , such as a bird returning after an absence , or the repulsion of an intruder , or the coming together of different coteries . The corroboree appears to have a bonding function , and may involve all members of a colony . 
 A ' corroboree ' ( from the word for a ceremonial meeting of Aboriginal Australians ) <a href='drop_aux' title='1'><mark>is</mark></a>a group display where birds converge on adjacent branches and simultaneously pose hunchbacked , giving wing @-@ waving and open @-@ bill displays and the yammer call . A corroboree <a href='uninflect' title='2'><mark>occurs</mark></a> when birds meet after a change in the social environment , such as a bird returning after an absence , or the repulsion of an intruder , or the coming together of different coteries . The corroboree <a href='uninflect' title='3'><mark>appears</mark></a> to have a bonding function , and may involve all members of a colony . 
A ' corroboree ' ( from the word for a ceremonial meeting of Aboriginal Australians ) a group display where birds converge on adjacent branches and simultaneously pose hunchbacked , giving wing @-@ waving and open @-@ bill displays and da yammer call . A corroboree occur when birds meet after a change in the social environment , such as a bird returning after an absence , or the repulsion of an intruder , or the comin together of different coteries . The corroboree appear to have a bonding function , and may involve all members of a colony .