The use of 1080 is opposed by some environmental groups. Campaigner Nicky Calcott told the New Zealand Herald there's little proof of the "plague", and said that 1080 has also been known to kill the endangered kea bird, native only to New Zealand's South Island. However the government, which has sunk NZ$21m (£10.8m; US$18.5m) into its "Battle for our Birds" programme over five years, insists that setting traps for millions of predators is not a viable or practical option. "People are dreaming if they think we can do this without poisons like 1080 - you can't trap 30 million rats," Dr Smith told Radio New Zealand