Whangarei's Native Bird Recovery Centre is calling for a ban on all leg-hold possum traps, after it was forced to euthanase three kiwi in one week.
Manager Robert Webb said two of the birds had infected broken legs, while one had half its beak snapped off.
He said he had no option but to put them down.
The kiwi - two big females and one male - were all the victims of traps thoughtlessly laid at ground level, said Mr Webb.
He said possum fur was fetching good prices, and more Northland hunters were getting into the trade, buying up cheap job-lots of used leg traps.
"We've seen this before where a kiwi has been going along, then probed a trap and the trap goes off and it cuts his bill off. It's just so frustrating because we see it at our centre there. These birds come in, and it's not a nice thing to have to put a bird to sleep, whether it's a kiwi or something else, because somebody couldn't care less."
He said traps that can't kill kiwi were available, but they were expensive.
The government should ban the use of leg traps in kiwi country, and make the safe traps cheaper, said Mr Webb.