Bone Talk by Candy Gourlay

Samkad lives in a tribe deep in the Philippine jungle at the end of the nineteenth century, and has never encountered anyone from outside his own tribe before. He's about to become a man, and while he's desperate to grow up, he's worried that this will take him away from his best friend, Little Luki.

However, Samkad's world is about to change utterly.

A strange man with white skin arrives in his village, and Samkad discovers the brother he never knew he had. A brother who tells him of people called 'Americans'. Americans who are bringing war, and burning, to Samuel's home...