Angry Birds scores did not transfer from iPhone to iPad
Although the developer didn't write the code to keep your progress in sync, you can manually move the save files and settings from identical versions of the App - sometimes even from iOS to a computer version of the game.

In a nutshell, you'll need software to poke into the Application's saved files - so you'll need a PC or Mac or to jailbreak both your iOS devices.

Second, you'll learn what files and check the versions and move the files.

Worst case, you crash the new empty version of the app, and delete it and try to move the scores a second time.

There are many tutorials on this. Our site and others have information on using PhoneView on the Mac, and a game site has a very well done tutorial that I will link below:


http://www.angrybirdsnest.com/how-to-transfer-angry-birds-progress-between-ios-devices/


Good luck - you'll learn more about how apps work, and hopefully not have to replay all those levels!