There was a lot of research into communicating with animals using sign language. I think it never went further than identifying objects, simple tasks and needs.

There was a lot of research into communicating with animals using sign language. I think it never went further than identifying objects, simple tasks and needs. Of course a lot of the research done back then was outright fraud, which might have interfered with alternative approaches. After all, why study alternative ways to communicate with animals when you can use sign language to discuss climate change with a gorilla.