September's aerial 1080 pest control operation at Rakaumangamanga/Cape Brett and Russell Forest had been even more successful than expected according to DoC's northern North Island operation director Sue Reed-Thomas.
The rat population in Russell Forest had almost been wiped out, she said, and possum numbers had dropped to 20 per cent of what they were prior to the operation.
Similar results had been achieved at Rakaumang-amanga, with no rats or mice detected and possum numbers down 90 per cent.
"These results show outstanding success, and prove the effectiveness of aerial 1080 to control pests in a large area over a short period of time," Ms Reed-Thomas said.
"These low levels of pests have allowed the spring breeding of native bird life to have a higher chance of survival, and the overall health of the forest will start to regenerate already. Native birds can produce more chicks, the ngahere can grow and provide kai to native birds, lizards and insects."