On Chakotay's first posting, his ship was sent to make first contact with them. He studied up on all the information they had on the Tarkannans, and pestered the captain to let him be on the diplomatic team. When he finally came face-to-face with their delegation, he very proudly made the traditional gesture for "hello", not realizing that males and females of their race used different styles of movement. He later found out that he had actually propositioned the ambassador.
Being as the Federation had information on them, it seems probable they were already a space-faring race when the Federation met them. It is also probable they were humanoid, Chakotay being able to imitate their gestures.