Pest-free Islands in Eastern Bay of Islands already showing signs of recovery

Helen —  29/04/2010

It’s starting to happen already!

Rare and endangered birds are already returning to the now pest-free islands of Ipipiri (eastern Bay of Islands).

Banded rail and kukupa (NZ Wood Pigeon) have been spotted on Motuarohia/Roberton Island. The first time in 30 years for the kukupa! A flock of more than 20 NZ Dotterel have also been sighted at Otehei Bay (Urupukapuka Island). We’re starting to see a carpet of coprosma seedlings under the kanuka cover. Rats would have eaten those seeds in the past before they even had a chance at life.

Thanks to the work of local hapu at Te Rawhiti, volunteer groups and trappers, (Guardians of the Bay of Islands Trust, the Eastern Bay of Islands Preservation Society, and Te Rawhiti Enterprises) it looks as if the pest control efforts on the mainland,  are helping keep the rats from swimming across to the islands. 

Now for the not so good news…

We can’t afford to be complacent, as three Norway rats were caught on Urupukapuka Island between December 2009 and April 2010.

This summer was the first real test of how well our biosecurity work on Project Island Song has gone. With hundreds of campers and thousands of boaties enjoying Ipipiri in the eastern Bay of Islands – there is great potential to bring rats back. We knew the risk that rodents would turn up. What’s great is that the community helped catch them. 

CSI – DOC-style!

DNA analysis by the University of Auckland showed conclusively that the first rat was not a survivor of the eradication operation undertaken by DOC in 2009. It is most likely that it was transported by boat from somewhere further away than the Te Rawhiti mainland. Rachel Fewster from the University’s Statistics Department has been doing the DNA surveying.

According to Rachel, “Our rodent invasion project is aimed at assisting island restoration projects around NZ by analyzing rat DNA to determine how rats arrive on islands. It is most useful to know that these animals are likely to have arrived by boat.”

The first rat crawled under a tent groundsheet during the night and was stood on by a surprised camper when they got up in the morning.

The second rat, also caught in Urupukapuka Bay in a trap left set by a camper, was too decomposed to undergo DNA testing.

The third rat was caught in Otehei Bay in a DOC trap and reported by a young visitor, we are still waiting on the DNA results to find out where it came from.

As soon as it was confirmed that rats had been caught extra traps and tracking tunnels were set up at each sighting point. These have been checked weekly since January with and it looks like more traps set at these arrival points each summer. 

Rats aren’t fussy!

The important thing to remember, with any pest-free island is to be extra vigilant. Rodents can find their way to the islands in ANY material that is transported there; this includes tents, bags, grocery shopping, metal, timber, machinery, umbrellas, etc. Please be responsible by checking your gear and boats before leaving.

And remember, rats aren’t fussy , they like clean boats and people as well! Your help will keep the islands pest free and don’t be scared to report a sighting!

Please contact the DOC Bay of Islands Area office if you see any rodent droppings or tracks while you are on the islands of Ipipiri. During office hours – phone +64 9 407 0300; afterhours 0800 DOCHOT (0800 362468)




I've been a 'greenie' since I was 13 and tried, unsuccessfully, to save a local stream from being turned into concrete slipway. I love working alongside people of all ages, backgrounds and interests and in my DOC role as a biosecurity advocate - I get to talk with just about everyone about how they can help keep the islands of the eastern Bay of Islands pest-free.