Whether they have any extant function or not, they have lost their former function and in that sense they do fit the definition of vestigiality. Vestigial structures are often called vestigial organs, although many of them are not actually organs.
There are quite a few birds famous for doing ritualized mating dances, so I would only list 5: The Red Capped Manakin, The Black-footed albatross, The Western and Clark's grebe, The Superb bird of Paradise, & The Victoria's riflebird.
Ever popular British jazz Funk band Shakatak recorded âNight Birdsâ in 1982 and remain one of the UKâs most accomplished proponents of this style. . The songs are catchy and the album includes three singles âNight Birdsâ, âEasier Said Than Doneâ and âStreetwalkinâ.