Rats found on Mokoia Island

A quarantine hut on Mokoia Island. SUPPLIED

Two rats with the potential to decimate bird populations on Mokoia Island were recently stopped in their tracks with strategically placed Department of Conservation trapping lines on the island's shoreline.

The traps had been laid out in such a way that any island invaders would be drawn to bait and be killed before having the opportunity to attack and kill saddleback, robins, weka, kokako and kiwi that live on Mokoia Island, part of which is a Wildlife Refuge.

The rodents were detected during a routine monthly bio-security check of the island.

"It's great to see that the trapping lines have worked in exactly the way we wanted them to," said senior ranger Erin Patterson.

"Although rats are good swimmers, it is unlikely that they would engage in the journey over to Mokoia when food supplies on the mainland are plentiful.

"It's likely that the rats were passengers on boats mooring at the island without a permit or sufficient quarantine checks."

A volunteer crew including members of the Mokoia Island Trust Board have made daily trips to the island as part of a Co-ordinated Incident Management Structure (CIMS) initiated by DOC.

The island will be searched by a trained rat detection dog before being returned to pest-free status.

Rats are known for reducing bird populations by eating young birds and their eggs and competing with them for seeds and fruit to eat. To prevent pests presenting on the island a permit is required to land and stringent quarantine procedures must be followed.

DOC is working with the Mokoia Island Trust to support them to lead the bio-security checks in 2015.