Different birds may have different advantages in-game (i.e. MMO enables players to chat online in established servers. In the third release, birds are able to nest and lay eggs that give the player extra lives when hatched. In all three games, the player is tasked to find chips that fill their 'poo-o-meter', which are often required in order to poo on traffic wardens and (in the later MMO features) other players.
