A scientist says 1080 is a relatively humane way of killing pests, but can be unpleasant for mammals.
The SPCA is calling for it to be banned, saying animals suffer horribly as they are dying from the poison and it wants birds and their predators to co-exist peacefully.
Forest and Bird says that's naive, and is not how nature works.
Otago University toxicologist Belinda Cridge says 1080 is a chemical that causes energy systems to shut down.
She told Tim Dower any animal can be affected and die if they eat enough, but it's been formulated to attract mammals to eat it, rather than birds.
"On the scale of poisons, it's not so bad. If you think about some of our other tools like rat poison, that is pretty horrible. On the scale, 1080 is relatively humane."
LISTEN ABOVE AS BELINDA CRIDGE SPEAKS TO TIM DOWER