Forest and Bird volunteers have spent about eight months monitoring the new automatic GoodNature humane traps on 30ha in the forest - home to one of the few remaining pockets of the robins on the east coast of the South Island - on behalf of University of Otago researchers.
Spokesman Mark Hanger, of Forest and Bird, said it was important to do what they could to help try to save the population, especially given its close proximity to Dunedin.
Using the traps, which targeted rats and stoats, was less labour intensive and meant poison was not going into waterways or was accessible by dogs, he said.
''The rat numbers have plummeted, which is really pleasing.''
Prof Ian Jamieson, of the University of Otago, said monitoring around the trap area had shown predator numbers were about half what they were outside the trapping area.
However, the survival rate of the robins within the trapping area was the same as outside the area - zero over two clutches at each nest.
The results showed either the reduction of rats and stoats was not enough to stop predation, or possums - which could not be killed by the traps - caused the predation, Prof Jamieson said.
''We hope to test these ideas next year by placing cameras on robin nests to detect which predator is causing the most nest predation.''
