The graph below shows rat levels before and after aerial 1080 operations that took place between 2012 and 2017. It shows results from a range of predator control operations.
Graph: Rat monitoring results for 2012 - 2017
The percentages are the rat tracking indices (proportion of tunnels showing rat tracking), which reflect relative rat abundance. Where the post-operation result is blank, a zero or undetectable rat tracking result was achieved.
While rodents will reinvade from surrounding areas, in the beech forest environment rat numbers generally stay low until the next forest mast or seeding.
DOC works to continually improve its predator control operations to achieve the best results possible. Knowledge gained from predator control operations in previous years has been used to improve and finetune our current programme.