Sunday, September 4, 2011

The use of 1080 in Okarito Forests

Today several helicopters have spread 1080 laced baits over the forests behind our village. It's all part of the DOC programme to kill the rats, possums, and stoats which threaten the survival of the Okarito brown kiwi "Rowi".

It's fair to say most people in Westland oppose the use of 1080. They have a variety of reasons; some passionately argue on the grounds of the inhumane treatment of animals - being poisoned by 1080 is not a pleasant end for any living creature. Others worry about their dogs, chemicals in water supplies, chemicals in the environment, so called "ecocide". Hunters object to the collateral loss of deer. I support the goal of destroying the pests but red deer are now officially a "game" animal. I wish DOC would take appropriate action to minimise deer losses.

To put this blog in perspective, I should disclosure that my early science career, in the 1960's and 1970's, involved calibrating how badly possums were destroying our rata and kamahi forests. The end result of this work was justification for sowing 1080 laden carrots over vast areas of mountain lands. The 1080 cetainly decimated the possums. The bush would stink of dead animals for weeks afterwards. But I fear how many birds, especially kea, we inadvertently wiped out. Since that time science has certainly refined the use of 1080 with the use of grain baits, cinnamon bird repellant and very low application rates compared to the old days.

Well after today's aerial action I took a walk in the bush to count baits. First impressions are that the sowing rates are really low. On an old trail which was still clear I found 13 baits over 500m distance. However, in undisturbed forest the baits were quite hard to find. They disappear into nooks and crannies under the fern cover. By the look of it I would expect rats and possums will be the main mammals affected. Where deer will be at risk is open ground such as well grazed grassy clearings and shingle river beds.

I've taken the trouble to count deer numbers from sign on a number of clearings over the last few weeks prior to poisoning. In a few weeks I'll return and try to estimate how many have survived. Watch this space.

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