We’ve just finished updating the Birdstack database to conform with version 2.1 of the IOC’s world bird list. If your data was affected by any splits or lumps, you will have a notification. For help with the upgrade process, check the taxonomic updates help page and the taxonomic updates screencast.
Version 2.1 contains 10,340 species classified in 39 orders, 224 families and 2198 genera. Highlights include addition of 14 species, including eight albatross species, and 19 English name changes including the Madeiracrest to Madeira Firecrest and Pediunker to Grey Petrel.
You can explore further at WorldBirdNames.org.