Forest and Bird says job cuts at the Department of Conservation will threaten endangered kakapo and kiwi and should be reconsidered.
The department has announced plans to cut 140 jobs as part of its bid to save nearly $9 million.
It says the cuts will be in administration and middle management but Forest and Bird's advocacy manager Kevin Hackwell says key roles in species recovery programmes will also get the axe.
He says the scientific and technical hands behind the kakapo recovery plan will go and so will the specialist knowledge they have.
Mr Hackwell says the jobs of rangers involved in kiwi recovery are also being cut.