A discovery that kea might be able to learn to detect toxic 1080 bait by how it looks could be a breakthrough in teaching them not to eat it.
The controversial poison is used widely to control pests on conservation land, but it also killed non-targeted animals and birds - including, sometimes, the endangered kea.
New research showed that an additive that made it "shiny", or that appealed to the parrot's ability to see ultraviolet colour, might be the tool needed to teach the curious alpine parrots to avoid the toxic pellets.
Kea Conservation Trust patron Peter Hillary said the discovery was timely.
The mountaineer, climber and adventurer said the country was on the edge of losing one of the world's greatest birds - and with them, a part of our identity.
"The kea are one of the world's most marvellous birds. They're one of the most intelligent birds, they're mischievous and curious.
"They're the epitome of being in the Southern Alps. The cry of the kea, to me is synonymous with those great mountains."
Zoologist and researcher Amy Brunton-Martin has applied knowledge that parrots - like other birds, can see ultraviolet colours, and adapted it to her research into kea.
She said it supported the theory that adding the bird repellent to pre-feed baits might prevent them sampling the toxic bait.
"Because there's a chance that kea might be able to detect a visual difference. It's important to ensure that any pre-feed bait resembles toxic bait as closely as possible.
"The main point is that parrots are quite inquisitive and like new things, so if they've learned to avoid a pre-feed bait, and then the toxic bait looks slightly different later on, then they might interact with it a bit less."
Dr Brunton-Martin said the research highlighted that how something looked, and not only smelled, was an important tool in protecting vulnerable, non-target species.
Kea Conservation Trust chair Tamsin Orr-Walker said the new research would link with other valuable work toward protecting kea.
"It's part of the puzzle. All of these bits of research we get are really important to making sure we get something soon, to minimise the risk of kea picking up 1080 bait."
The research was backed by Department of Conservation subsidiary, Zero Invasive Predators, and included a study using non-toxic bait and a fluorescent dye additive, pyranine.
But it was not yet clear if the pyranine shine was too appealing to kea, or whether it could be used as a tool to teach the birds to steer clear of 1080.
What was clear, is that kea were good students.
University of Auckland experts found recently that the birds could judge statistical odds in a way only ever seen before in infants and great apes.
PhD student Amalia Bastos said work in their lab suggested that kea could learn an aversion to certain things
"So it is possible to teach them not to approach cereal bait pellets that don't contain the poison, and then when you do introduce ones with the poison they might be able to avoid it because of their previous experience.
"If we can have the fluorescence in the pre-poison bait, and which they learn the aversion to, then that would help them identify it is the same object."
Bastos said the discovery that kea could possibly discern by sight and not only smell, was very good news.
She said it would add to the arsenal of deterrents being developed that might warn kea off from poisonous bait.
"One of our collaboratives is looking into whether they might or might not be interested in the smell of cinnamon, which could be applied to the baits to repel them - cinnamon is a natural repellent to birds in some cases."
Peter Hillary said the use of 1080 would remain a troublesome challenge, until an alternative was found.
"It's a difficult one, and I can understand both sides of the argument, but we have a marvellous and completely unique ecology here in New Zealand and it's in our hands as to whether or not we preserve it, or whether we relinquish it, and that's a critical question."