Traditionally, shields were carved prior to a headhunting reprisal
raid, which was organized to avenge the death of the ancestor for whom
the shield was named. A shield always represents an ancestor. It is
named after him and the ancestor's spirit is believed to be present in
the shield and make the owner fierce, powerful and invincible. Shields
are considered so powerful that it may control the owner. Shields also
provide spiritual help to the owner in hunting regular prey for food.
shield is carved out of the lightweight flattened (or plank) buttress
root of a mangrove tree-- the root is planed to half an inch thick,
except for a protrusion left on one side for a handle. The front of the
shield is carved in high relief. They include symbols of wild boar
tusks or bones, flying foxes, the tails of tree kangaroos, whirlpools.
Some symbols are believed to be so powerful that just by seeing these
symbols, the enemy will flee in terror or be immobilized in fear. But
such powerful symbols require strict rituals of appeasement. A special
feast, the yamas pokumbu is held to call upon the ancestor's spirit to
enter the war shields.
The spirit in the shield must be properly
treated or it might cause disease, or doom hunting efforts and rot the
sago palms. During festivals, shields are decorated with tassels of
sago leaves and placed near each other so the spirits may interact.
Shields are placed near doorways to protect the home from evil spirits
and human intruders.
Shields from different areas have different
features: some have a phallic protrusion at the top; others have a
symbolic head at the top, yet others add facial features of the
ancestor at the top.