Since 2010 DOC has been monitoring a range of birds in forests in South Westland to measure the effect of repeated use of 1080 on them.
This work is being undertaken in three forest blocks near Lake Paringa:
- In one block there is no use of 1080 for pest control
- In another block 1080 is used in a way designed to maximize the benefits to forest birds
- In the third block 1080 is used on a regular timetable
We closely monitor the productivity and survival of three forest birds - morepork, kaka and rifleman - using radio transmitters, bands and by finding and monitoring nests. For these species we are able to detect any mortality caused by 1080, and any improvement in productivity and survival caused by any reduction in stoat, possum and rat numbers.
We also monitor all forest birds by counting their calls. Digital audio recorders are placed in the forest at 300 pre-determined points every summer and the number of birds heard calling on the resulting “tapes” are counted. This data enables us to detect changes in bird abundance, but does not enable us to attribute the changes to 1080 bykill or to improved productivity and survival.
None of the 20 radio-tagged moreporks monitored through a 1080 drop in South Westland, died
This work is still continuing so we have no final results, however we do have some important preliminary findings:
- Kaka are not killed in 1080 operations. We have monitored 25 radio-tagged kaka through two 1080 operations in South Westland, and a further 70 kaka in other parts of the country. None have been killed by 1080.
- None of the 36 banded riflemen monitored during one 1080 drop in South Westland, died.
- None of the 20 radio-tagged moreporks monitored through a 1080 drop, died. Nor did any die in a 1080 drop in Waitutu Forest.
- The incidence of predation of kaka nests by possums and stoats is lower immediately after 1080 operations than it is at other times.
- Kaka, bellbirds, tits and parakeets are all more abundant in the two forest blocks that have been treated with aerial 1080 than they are in the block that has never been treated with aerial 1080. All other forest birds were equally abundant in both the treated and untreated forests.