The birds were among 12 kea monitored by the Kea Conservation Trust to study the impact of predators, with six birds confirmed alive since the DOC operation on 11 February.
DOC is concerned the tracked kea may have been exposed to human food around the tramping huts in the valley making them potentially more vulnerable to picking up 1080 cereal baits, says DOC Threats Director Amber Bill.
“While we are confident that predator control operations benefit kea populations at large, it’s upsetting to lose six birds.
“We won’t know the cause of death until we get post-mortem and toxicology results back.”
Amber Bill says the Matukituki predator control operation followed DOC’s Code of Practice to mitigate risks to kea from 1080 and ensure they benefit from stoat control after a forest mast.
“Last year’s forest mast was the biggest in 40 years, fueling rodent plagues and a spike in stoat numbers, and posing a serious threat to ground-nesting kea and other native wildlife.
“Our work to mitigate the risk to kea from 1080 is based on extensive research and the results of 222 monitored kea through 19 aerial 1080 operations at 12 South Island sites.
“This research shows the risk of 1080 to kea in remote areas is low but increases markedly with birds that have learnt to scavenge for human food.”
Research also shows that kea populations are better off when aerial 1080 is used to control rats and stoats, with increased survival and nesting success.
“We are constantly trying to reduce the risk to individual kea by regularly reviewing our predator control and kea mitigation standards based on the best science available including new kea studies,” says Amber Bill.
The Department is currently scoping social science research to inform a public campaign to discourage people from feeding kea and interaction that could lead to scrounging behaviour.
DOC worked with the Kea Conservation Trust to recover the dead kea and the birds have been sent to Wildbase at Massey University and Maanaki Whenua Landcare Research for post-mortem and toxicology testing. Results are expected later this week.
DOC’s published research on kea survival through aerial 1080 operations used results from 222 monitoring cases involving 205 individual kea through 19 aerial 1080 operations at 12 South Island sites between 2008 and 2016 to model kea survival.
Overall, there were 24 kea deaths all within six of the 19 aerial 1080 operations and only three deaths out of 110 monitored kea at remote sites.
The 1080 predator control operation in the Matukituki valley, part of DOC’s Tiakina Ngā Manu programme, aimed to protect rock wren/pīwauwau, kea and whio, as well as kākāriki, kākā, and South Island robin/toutouwai from a beech mast-fueled rat and stoat plague.
Previous aerial 1080 operations within the valley in 2014 and 2017 were successful in reducing rodent and stoat numbers to very low levels.
DOC values the work of the Kea Conservation Trust, which has monitored kea in the Matukituki since 2016. The Trust’s monitoring is focused on understanding the local kea population and how predators are impacting on their survival and breeding success. The monitored kea included birds caught around huts in the valley.