DOC responds after possible rat sighting on Hauturu/Little Barrier Island

The Department of Conservation (DOC) has activated a response plan following a possible rat sighting on pest-free Hauturu/ Little Barrier Island in the Hauraki Gulf.

Hauturu is a pest-free nature reserve that’s home to around 40 species of rare or endangered native birds, plus wetapunga and native lizards. There are more than 400 types of native plants in the native forest that covers the island.

Rats are a major threat to native wildlife. They eat eggs and chicks of native birds. They eat native lizards and weta. And they eat seeds and flowers depriving native birds of food.

A DOC ranger looking under a shelter on Hauturu, late on Wednesday afternoon(Dec 6), saw something move that may have been a rat.

The shelter is 632 metres above sea level on a steep ridge. It takes five hours to walk to the hut, on tracks, from the DOC base on the island’s coast.

“The area under the shelter was very dark. The ranger caught a brief glimpse of something retreating into the darkness. His initial thought was that it could have been a rat or a robin, a bird that spends a lot of time on the ground eating insects,” says DOC Auckland Inner Islands Operations Manager Keith Gell.

The ranger checked a rodent tracking tunnel under the shelter. The tracking tunnel has an ink card to pick up track marks if a rat or mouse walks through the tunnel. There were no rat tracks on the card but the ink may have become too dry.

The ranger viewed the card with a magnifying glass and saw what he thinks may have been tiny hairs.

The ranger placed the ink card in an evidence bag. The ink card has been flown by helicopter to the mainland to be examined by DOC scientists.

“We need to know if there is, or isn’t, a rat on Hauturu. So, we’ve launched a response plan to determine if a rat has made it to the island,’’ says Keith Gell.

“This morning (Friday Dec 8) we flew a DOC ranger with a rodent detecting Conservation Dog to Hauturu by helicopter. They searched under and around the shelter and the surrounding area. No trace of a rat was detected by the Conservation Dog.”

“We’ve set up a network of devices at the shelter site to see if we can detect a rat,” says Keith Gell.

The network includes three motion sensor cameras, that can record images day and night. Tracking tunnels with fresh ink cards, chew cards that record a rat’s teeth marks and rat traps. The tracking tunnels, chew cards and traps are baited with peanut butter that is proven to attract rats.

“A ranger is staying in the shelter for the next week to monitor the cameras, tracking tunnels, chew cards and traps as part of our response plan to determine if there is or isn’t a rat on Hauturu,” says Keith Gell.

DOC works in partnership with Auckland Council to protect the pest-free islands in the Hauraki Gulf.

“We have biosecurity systems in place, to protect these pest-free sanctuaries because there’s an ever-present risk of a pest making it to one of these islands,” says Keith Gell.

“As part of our biosecurity systems, we’ve activated this plan to determine if there is or isn’t a rat on Hauturu,” says Keith Gell.

“Just over three weeks ago we activated a response plan after a possible mouse sighting on Tiritiri Matangi. We have found no trace of a mouse on Tiritiri Matangi and are looking at scaling back that response,” says Keith Gell.

Additional information

To protect the native wildlife and native forest on Hauturu, every visitor requires a permit from DOC and is subject to strict biosecurity measures. Hauturu is 21.4km from mainland Auckland.

DOC’s Conservation Dogs Programme is supported by Kiwibank

http://www.doc.govt.nz/conservationdogs

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