You’ve got to chuckle at the sight of dozens of vultures joyously singing “Food, Glorious Food” as their potential meals make the hard slog across dry land. Laughs again come when one large mammoth’s idea of seduction is to tell his female counterpart, “Your butt’s huge. Biggest darn butt I’ve ever seen.” Too bad “Ice Age 2” couldn’t maintain that consistency all the way through.