The Others is what the characters in the Guardians of Ga'hoole series refer to humans as.
The Others are discribed by owls as being an ancient race that used to reside in the owl kingdoms long ago. Many of their structures and artistic works remained and are used by owls in the present day. They are heavily implied to be humans by Trader Mags, Bess and Otulissa throughout the series, and this is proven in Rise of a Legend, when several owls, including Ezylryb, discover a modern-era human whom they refer to as an Other.
While Otulissa was writing A Guide Book to the Great Tree, she felt there was a scroom of an Other that guided her. She revealed to the readers that the author was named Kathryn Huang (Lasky) (the real author of the book).
Blix and Loki, two of Lyze's friends on Dark Fowl, discovered the frozen body of a modern Other in an ice cave. They leave the cave, but later come back and show Lyze. The Other is wearing a soft, woven material and a backpack, with several hooks and loops with latches attached to him. (Lyze later identified these as carabiners, used in an Other activity known as mountain climbing.)