Are Chimpanzees Bilingual?

Recently Frek the chimp and eight of his friends moved from a Dutch zoo to a Scottish zoo, but their address wasn't the only thing that changed.

Scientists at the zoo noticed that the pitch of the chimps changed as they socialized with the Scottish chimps. Not exactly burr, but different.

Animal reporter Vicki Croke joins Here & Now's Jeremy Hobson to explain what scientists are learning about language evolution from these chimpanzees.