Special report
A new study shows tuatara could be at risk from rodenticides that are being used to protect them from rats.
However research by scientists which included examining four dead tuatara showed they were likely to have been exposed to brodifacoum, used to kill rats.
It seems likely the tuatara ate small rodents or invertebrates that had fed on the toxic baits.
Massey University Professor in wildlife health Brett Gartrell said the research would have implications for both the tuatara and how to care for them.
Brodifacioum is widely used in New Zealand to control rats and mice and care is needed to ensure that native wildlife are not affected he said.
University of Auckland school of biological sciences Professor James Russell said brodifacoum was a powerful toxin and the study presents evidence of it causing harm to tuatara.
“Indiscriminate use of toxins can cause unintended harms as was certainly the case here. However toxins are also important in managing threats to reptiles – the greatest off which is introduced rodents.”
“Brodifacoum is a slow acting poison that is far worse than even 1080 poison,” commented Laurie Collins convenor of the Sporting Hunters Outdoor Trust. “Whereas 1080 has a withholding period of several months, brodifacoum has 36 months. That shows the difference. Both are harmful to invertebrates. Both have secondary poisoning properties. A tuatara eating a poisoned bug – dead or in the throes of dying – gets a dose of the poison too. After all 1080 was originally patented as an insecticide in the 1920s.”
“It’s incomprehensible that the Department of Conservation does not seem to realise this and that these toxins are indiscriminate, and poison non-target species as in this case, sadly, tuatara,” he added.
Laurie Collins said it was not only tuatara that ran the risk of being poisoned by toxins such as brodifacoum.
“Predators such as the native falcon and morepork and insectivorous birds like robins, fantails and tomtits also get poisoned by these toxins with the property of secondary poisoning.”
Brodifacoum Warning notice by Waikato Regional Council
What other effictive control measures would be suggested.
No control needed at all you cannot sort out nature’s problems let nature sort it out itself it is the best problem solver of all at no cost.
It looks like survival blindness from DOC to ignore the broad spectrum effect of 1080. Minister Jones gleeful negativity about Freddy Frog has been seen as a directive to destroy any habitat or species that happens to get in the way of somebody making a buck. So sad.
Ulva Island in Patterson’s Inlet at Stewart Island was poisoned over three years ago with brodifacoum there is still a ban in place for taking fish and shellfish around the Island after brodifacoum was found in blue cod livers and shellfish.
NZ Journal of Ecology 1995 – research by Charlie Eason and Eric Spurr, 1995 – “Because of the high toxicity of brodifacoum, all vertebrates that eat baits or poisoned prey are at risk.”
Anyone who reads the Safety data sheet on brodifacoum will see printed across the front of the document “Do not release into the environment.”
I agree with Laurie Collins brodifacoum is much worse than even 1080. 1080 gets the media attention but to the unsuspecting, brodifacoum seems to be acceptable. The poisoners are pulling the wool over the eyes of farmers and the public.