Motutapu and Rangitoto September 2009 project update

Third and final bait drop successfully completed

Third bait drop
What's happening now?
We need your help

Third bait drop

The third and final phase of the three-stage aerial rodent baiting operation was successfully completed on August 7. The weather once again played its part, with the calm sunny conditions and thorough planning once more resulting in a textbook operation that took less time to complete than anticipated.

Rangitoto and Motutapu islands

An effective and efficient team of DOC staff and volunteers from the bach community, Motutapu Restoration Trust and Motutapu Farm Ltd again descended on Rangitoto and Motutapu to complete the third bait drop. All the the islands' nearly 340 structures have now been hand-baited four times. Baits were again cleared from beaches following the third bait drop to reduce the risk to New Zealand dotterels. Dotterels continue to be observed on Motutapu with no casualties reported to date.

Following the final aerial application, bait has now been removed from all sensitive locations on the islands. DOC staff assisted Motutapu Outdoor Education Camp staff clear bait that was laid around the camp, in preparation for the camp to open again on November 1. All bait stations have now been removed from baches, houses and other structures across both islands, and water-collecting roofs and guttering have been cleared prior to water supplies being reconnected.

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What's happening now?

Loading bait into a helicopter on
Motutapu

The eradication of the seven remaining mammalian pests on Rangitoto and Motutapu does not end with the last bait drop. As the aerial application targeted rodents, the focus has now been shifted to the other four mammalian pests. DOC staff and contractors have already begun intensive follow-up work on the islands for rabbits, stoats, hedgehogs and wild cats, together with traps for remaining rodents. This follow-up work is expected to be undertaken for a period of up to two years, and includes trapping, shooting, the localised use of bait and the use of dogs.

Rabbit follow-up work began with spotlight surveys across the whole of Motutapu and areas of Rangitoto where rabbits have been recorded. In the two weeks the surveys were undertaken just one live rabbit was sighted, an early indication that the rodent bait has, as expected, impacted on the rabbit population. Ten specialist detection dogs are now being used to sniff out any sign of rabbits, and to date, no further rabbits have been detected.

The trap network across Rangitoto and Motutapu have been activated for stoats and hedgehogs. Numerous hedgehogs have been found dead, but live hedgehogs are still being seen on Motutapu. Rodent traps have also been deployed across the 1,100 trap network. All traps were baited and set at the end of August and recent checks of more than half the traps on Rangitoto have found nothing! Interesting, all the stoat traps were pre-baited (unset) befor the beginning of the aerial bait drop. On Rangitoto all the bait was taken. However, the recent checks reveal no bait take - a promising sign for the eradication project.

Unloading stoat boxes on Motutapu

The number of paradise ducks and pukeko found dead has now tapered off, and both species are still present in low numbers on Motutapu. "There was a big population of pukeko on Motutapu and we expected to lose a number of these birds. Previous rodent eradication operations have shown that pukeko populations bounce back very quickly, especially in the absence of predators such as rats and stoats," Auckland Area Manager Brett Butland explains.

Wild cats are still being seen alive on Motutapu, and appear to have been foraging on poisoned paradise ducks and pukeko. Cat trapping is now underway with three wild cats trapped to date.

Now that the aerial bait drops have been completed, DOC is planning for a return to business as usual on the islands. Rangitoto and Motutapu re-opened to the public on August 15. The islands will remain open during the follow-up pest eradication phase, but the public are asked to stay on public tracks. Stock are planned to be returned to Motutapu in October, and the Home Bay campsite, closed since June 1, is due to be re-opened for the summer season on November 1.

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We need your help

Now that Rangitoto and Motutapu are on their way to becoming pest free, we need your help to keep them that way by being vigilant about any rodent stowaways and reporting and signs of pests or inappropriate behaviour on the islands.

Prevention is better than cure, so we are asking visitors to reduce the risk of pests reinvading. Simple steps you can take include:

• Check your gear for pests - rats, mice and ants. Take extra care of you have Argentine ants where you live.
• Clean footwear and camping gear, removing soil and seeds.
• Pack food into sealed containers to keep pests out. Open supermarket bags are unacceptable.
• Report sightings of pests - phone the 0800 DOC HOT line (0800 362 468).

Taking your own boat or kayak?

• Check your vessel for stowaway pests - rats, mice and ants - before departing.
• Look for signs of rodents - droppings or gnawed items e.g. wiring.
• Keep fresh bait and/or set traps on your vessel or where it's stored.

For more information on what you can do to help protect conservation islands in the Hauraki Gulf Marine Park, visit www.treasureislands.co.nz.

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