DOC monitors rat numbers using tracking tunnels containing ink pads, before and after predator control operations to gauge their success.
The graph below shows rat levels before and after aerial 1080 operations in 2019 and early 2020. These operations were part of DOC’s Tiakina Ngā Manu predator control programme in response to the 2019 widespread forest mast or seeding.
Rat monitoring results before and after aerial 1080 during 2019/20 | View larger (PNG, 423K)
The rat tracking index (y-axis) is the percentage of tracking tunnels with rat prints. It indicates rat levels. Where the post-operation is blank (0%), rats were undetectable.
While rodents will reinvade from surrounding areas, in the beech forest environment rat numbers generally stay low until the next forest mast.
DOC works to continually improve its predator control operations to achieve the best results possible. Knowledge gained from these results will be used to improve and finetune future programmes.