I've heard that they are available in some of the other modpacks. Mostly, I just want to be able to spawn a couple tiny birds in my nature preserve.
typically the game is a bit wierd on servers, but in the past there have been some workarounds, like the twilight forrest situation back in infinity
and villager and coven witches and a book which describes how amazing i am hahhahahha i'm joking we dont need the villager and witch eggs