In your device settings tap on iCloud. Make sure the account information is correct and corresponds with the account you purchased iBird with and the account information on your other device. Scroll down and make sure “Documents and Data” is on. Tap on Storage & Backup. Make sure “iCloud Backup” is on.
In the iBird app under iCloud Settings (from the More page) Make sure iCloud Favorites and iCloud Notes are set to ON on both devices.
After you have enabled iCloud close iBird and turn off your device then restart.
To make sure you have set up your iCloud account correctly here is a link to Apple’s How to set up iCloud page:
Here is a link to a discussion forum for people that are experiencing problems with iCloud: