"We're right in the middle of breeding season and it's about now when the young ones start to come out of their burrows ... so there's particularly high numbers at the moment," he said.
About $20,000 is spent on pest control on Mauao each year. This involves tri-monthly night shooting, pindone poisoning and the efforts of Forest and Bird volunteers, who monitor about 80 traps all over the hill. The night shooting ceases between December and February, when the region was busy, Mr Ray said.
"Prior to Christmas we did out the first round of pindone poisoning but the babies weren't getting poisoned. They were still in their burrows, so now that the majority are out and moving, with the second round of poisoning going down, the numbers should reduce significantly."
Stoats are another major pest on Mauao.
"They are little killing machines and they can cause extreme devastation," Mr Ray said.
Stoats ate rabbits, rats and other animals as well as bird-life, which lived around the Mauao coastline.
"We are working on putting an application into the Rena Recovery Fund to encourage more sea life and boost the numbers following what we lost because of the oil from Rena," he said
The Mauao coastline was home to grey faced petrels, diving petrels and little blue penguins, and these birds were targeted by stoats, he said.
"[Rabbits, stoats and rats] are definitely pests and I'd love it if they could be eradicated but I don't know how realistic that is, unless we dump a lot of 1080 that's not going to happen."
Whenever pest control was taking place, the 180-odd sheep and lambs that currently lived on Mauao, were moved to other paddocks so they weren't affected by the poison.
The pest control work is undertaken alongside the Bay of Plenty Regional Council.
