The SPCA is calling for a ban on pest control poison 1080 over concerns about animal welfare.
In a statement issued this week, the charity said it was "deeply concerned" over the use of 1080, and the use of poisons to kill animals due to the level of suffering they caused.
Environmental organisation Forest & Bird has called the SPCA's position "naive", and one that would lead to "cruel deaths and extinctions" of native birds.
Sodium fluoroacetate, more commonly known as 1080, is a poison, mixed into baits, and used to control the numbers of a range of mammalian species, particularly possums and rats.
The SPCA called for a greater emphasis on finding ways for species that could not be completely removed to co-exist with native birds, and for finding more humane methods of pest control.
While it did not regard the lives of one species over another, the SPCA recognised there was a concern regarding "the impact of so-called 'pest' animals".
"Sometimes it is necessary to capture certain animals or manage populations of species for various reasons, including biodiversity, conservation and sustainability.
"In these instances, methods that are proven to be humane and effective should be used.
"The welfare of all animals should be viewed equally, and people should recognise that they deserve protection from suffering pain or distress, regardless of the species or where they came from."
Forest & Bird chief executive Kevin Hague said the SPCA's position showed a "naïve failure" to understand how nature works in the wild, and they would be seeking a meeting with the organisation to discuss its position.
"Their position reflects their history of caring for domesticated animals such as cats and dogs, without understanding the needs of New Zealand's native animals and ecosystems.
"While the idea of stoats and rats peacefully coexisting with native birds sounds great, the reality is that an estimated 25 million native birds, eggs and chicks are cruelly eaten alive by introduced predators every year in New Zealand.
"This is the terrible death that countless native animals across New Zealand suffer every night.
"The SPCA's position on 1080 is a blow to their credibility. It's sad to see them promoting flawed logic whose outcome is the extinction through being eaten alive of treasured animals like our kiwi, kereru and kokako.
"Without scientific, ethical and precision pest control, of which 1080 is a key tool, there is no way to protect our native animals from the overwhelming numbers of introduced predators.
"Giving up 1080 would lead to an ecocide of huge proportions in New Zealand, and the SPCA need to understand this is the outcome of their pest control position."
The SPCA's statement comes after 2018 saw anti-1080 sentiment ramp up.
DoC rangers were on the receiving end of death threats, and in September protesters laid the carcasses of native birds on the steps of Parliament in protest of 1080 drops.
The protesters claimed the birds, including two kererū, two weka and a red-billed gull were killed by 1080 poisoning.
However, official autopsy reports found two of the birds had been killed by vehicles, two were likely to have flown into windows, one was too decomposed to tell the cause of death, and an adult male weka had been shot, most likely with a .22 rifle.
In December the Environmental Protection Agency released its annual report into the aerial use of 1080 during 2017, stating it believed the current rules around 1080 "keep people and the environment safe".
"1080 remains one of the most strictly controlled hazardous substances in New Zealand and is a critical tool in the ongoing fight to protect our native birds from introduced predators – possums, rodents (rats and mice) and stoats," hazardous substances group general manager Dr Fiona Thomson-Carter said.