Study shows survival of monitored kea in aerial 1080 operation

Research into the outcomes for kea of aerial 1080 predator control operations has found all kea monitored during a recent aerial 1080 operation in Kahurangi National Park survived.

In the monitoring, 13 kea were caught and tagged with radio-transmitters prior to the Animal Health Board operation in June over 15,000 hectares on the eastern slopes of the Arthur Range. All 13 kea were found to be alive one month after the operation.

The kea monitoring was part of a three-year research programme looking at the benefits and risks of 1080 to kea. The study is measuring kea nesting success resulting from 1080 predator control, survival of kea, and researching operational methods that provide the least risk and most benefit to kea.

Department of Conservation Scientific Officer Josh Kemp, who leads the kea research programme, said monitoring of kea in the Mt Arthur area would now focus on kea nesting results over the next two years to determine the benefits of the 1080 pest control for the kea.

“We would expect kea nests to do well in the Mt Arthur area this year as aerial 1080 operations achieve large reductions in numbers of possums, rats and stoats that prey on eggs and chicks. A previous study in Nelson Lakes National Park found about 40% of kea nests were preyed upon by various pests. Adult kea can also be killed by introduced predators.”

Mr Kemp said research staff would be monitoring the movements of the eight breeding age adult kea among the 13 currently radio-tagged Mt Arthur kea to locate their nests and evaluate survival of eggs and chicks. This monitoring would follow the nests up until around Christmas when chicks fledge and become independent.

“If we can catch and radio-tag other adult kea in the area we will also monitor their nesting success.
“We will also be monitoring kea nesting success in the Crow Valley on the other side of the Arthur Range where no pest control has taken place for comparison purposes.”

Mr Kemp said aerially-applied 1080 was currently the only tool available for the large-scale pest control required to protect species such as kea that are sparsely spread over large areas.

“We are carrying out this research programme in conjunction with the Kea Conservation Trust and the Animal Health Board because we need to know whether the benefit achieved by reducing predation on nests, enabling kea populations to increase, can outweigh the risks to individual kea.

“We set baiting specifications for the Mt Arthur aerial 1080 operation that we considered posed less of a risk to kea. The 100 per cent survival rate shows the risk to kea can be reduced through such baiting practises without compromising pest control effectiveness as the method used is known to be effective in killing predators.”

The data from Mt Arthur will be used along with data from other study sites to predict the likely outcomes of long-term aerial 1080 programmes for kea numbers.

As part of the research programme, the Kea Conservation Trust is leading, with support from DOC, research into developing a bird repellent that could be mixed into 1080 baits to deter kea and other birds from eating baits.