I would like to know what proof you have that the birds in Sonic Adventure are not Flickies. We all know that they come in a variety of shapes and colors.
Their design doesn't match up with the original Flicky or any of the Sonic 3D Flickies either.
Calling Sonic Adventure's bird trio "Flickies" was always just a fan assumption thing. But Sonic Adventure's penguin isn't a Pecky, the seal isn't a Rocky, the rabbit isn't a Pocky. There's nothing to suggest that the birds should be thought of any differently.
I am reluctant to agree.
I also agreed with Pengi - Amy Rose called the bird that crashed into her "Bird" or "Birdy", but never "Flicky" as far as I know. Same thing go for Eggman, he yelled "get that bird" before sent E-102 to grab it from Amy Rose while she was in the prison, only to have E-102 freed them instead.
So make that those animals appearing in Sonic Adventure more "normal animals" than the ones coming from Sonic's world.
Still just Birdie. It does, however, confirm the relationship between the three of them, saying that Birdie is one of 3 siblings (兄弟 - kyoudai).
Sorry to bump, but I removed speculation of the Sonic X's Flicky page.
If that user kept up with adding the flicky word back in, feel free protect them. Or lock him up for a day.