Pre-Columbian plate with driven bird figures

This presumably red copper plate with covering layer of precious metal (gold or silver?) contains about 20 bird figures, driven into individual lozenges. \The plate is possibly a head ornament or part of a head ornament. There are holes in the side to attach it to some kind of headdress. The plate comes from a grave, so was a grave gift. According to the vendor the plate dates from the eighth century and would have come from Lambayeque (north coast of Peru).