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.
Birds have high basal metabolic rates & so use energy at high rates. Among birds, songbirds (passerines) tend to have higher basal metabolic rates than nonpasserines. And, of course, the smallest birds, hummingbirds, have the highest basal metabolic rates of all birds.In general, basal metabolic rate (or BMR) is related to mass, with larger birds expending less energy per unit weight than smaller birds.irds have high basal metabolic rates & so use energy at high rates. Among birds, songbirds (passerines) tend to have higher basal metabolic rates than nonpasserines. And, of course, the smallest birds, hummingbirds, have the highest basal metabolic rates of all birds.