Fish & Game New Zealand spokesperson Richie Cosgrove said a contractor was sent to try to locate and appropriately dispose of the birds.
Cosgrove said dumping, or drinking while hunting, is illegal and unacceptable.
“We condemn the dumping of bird remains in this way, it’s unacceptable and it’s against the rules,” Cosgrove said.
“It’s also a requirement in the region’s regulations to retrieve shot game in a timely manner and people can be prosecuted for failure to do that.
“We want to get to the bottom of this and Auckland/Waikato Fish & Game is investigating.”