“Mirrors or mirror-related toys are often provided to Budgerigars as a substitute for social interactions with a plethora of different mirror toys available for purchase. Despite widespread use, exactly how mirrors relate to social behaviors (i.e. actions directed towards conspecifics within a flock) remains a mystery in Budgerigars.”
That’s to say, with reference to Budgerigars :
“ […] the relationship between mirror use and social behaviors is in need of elucidation.”
Elucidation comes in the form of a paper by Professor Matthew Anderson (and colleagues) entitled : ‘Budgie in the mirror: An exploratory analysis of social behaviors and mirror use in the Budgerigar (Melopsittacus undulatus)’in Behavioural Processes, Volume 135, February 2017, Pages 66-70.