Seven kea have died at Fox Glacier after eating 1080 poison, wiping out almost half a group of the endangered and protected parrot being monitored by the Conservation Department.
DOC is reviewing its use of the poison after the deaths were revealed in a draft internal report, obtained by The Dominion Post. The report says "aerial 1080 may well be a significant threat to the kea population" with some drops "probably devastating".
DOC fitted radio transmitters to 29 West Coast kea - 10 in Arawhata Valley, two in the Hohonu Range, and 17 near Fox Glacier - to see if they survived 1080 drops. All birds in the first two areas survived, but seven near the glacier died.
Testing confirmed 1080 poisoning. The report says birds living near Fox Glacier were more used to taking food from humans, which may have made them more likely to take 1080 bait.
The report recommends that DOC review its use of 1080, consider cutting the amount of toxin in the bait where kea live and reassess the use of "pre-feeding", putting harmless baits out before 1080 drops.
It says some 1080 drops were probably devastating to kea populations, but others had minimal impacts or even benefited them.
DOC senior adviser Herb Christophers said the report was a draft only and more work had to be done before the effects of 1080 on kea were established.
Though DOC would review its 1080 activities near kea habitats, drops in the North Island would continue. The poison is used to control possums, rats and stoats.
Anti-1080 campaigner Mike Bennett said the kea deaths were the tip of the iceberg.
"These are only the monitored ones. If that percentage is extrapolated for the entire population, that doesn't leave many for the next drop."
He called for a ban on all aerial 1080 drops in alpine areas.