Dozens of pest sightings on Hauraki Gulf islands in last three years

Tuesday, 1 September 2020

Nine weeks after first being spotted, an elusive stoat is still on the run from the Department of Conservation on Auckland's Motutapu and Rangitoto islands (video first published July 25, 2020).

There have been 27 confirmed or suspected pest sightings on island wildlife sanctuaries in Auckland’s Hauraki Gulf in recent years.

Many of the islands in the gulf are pest-free and are havens for native wildlife, many of which are threatened or at-risk, such as kiwi, takahē, tūturuatu/shore plover, tīeke/saddleback, kākāriki/red-crowned parakeet, korimako/bellbird, and shore skink.

Between 2017 and May 2020, rats, stoats, mice, cats and rainbow skinks have made their way to islands in the gulf, according to Department of Conservation data.

The latest sighting involved an island-hopping stoat which continues to outsmart authorities.

* Island-hopping stoat: Fresh tracks detected on Motutapu and Rangitoto islands

Most of the 350 traps on Rangitoto and Motutapu contain the “classic rabbit and egg bait” to try and catch the stoat.

* Stoat could be island hopping in Auckland's pest-free Hauraki Gulf

Stoat footprints were spotted by a ranger on Motutapu Island in Auckland’s Hauraki Gulf on May 20, just a few weeks after a stoat was confirmed on the neighbouring Motukorea/Browns Island in mid-March.

A female Norway rat was found in a trap on pest-free Motuihe Island on July 26, 2019.

Stoats pose a significant risk to threatened native birds and lizards – the stoat on Motutapu Island killed a kākāriki in May.

For 13 weeks there has been a network of about 350 traps filled with a mix of lures, which are checked weekly, across Motutapu and Rangitoto islands to catch the elusive stoat.

Other confirmed pest sightings across islands in the Hauraki Gulf included two mice, five norway rats, three rats, three cats, a stoat and rainbow skinks.

Five rainbow skinks made their way onto Rakino Island in freight on May 1, 2017.

Two of the skinks were caught by hand as they escaped the package and the other three were later trapped by Auckland Council.

A cat was spotted by a member of the public on Motutapu Island on February 3, 2018, and again three days later.

Stoats pose a significant risk to threatened native birds and lizards.

Some dead birds were found, prompting detector dogs and traps to be deployed.

There was no further sign of the cat found, so it is thought it may have been removed by its owner.

On April 28, 2019, a cat was seen with its owners on the same island by a member of the public.

Traps and detector dogs were deployed, but there was no sign of the cat.

After tracing the owner, the Department of Conservation (DOC) learned the owners had returned to the island and collected it.

Some of these confirmed sightings cost DOC a total of $87,830.

David Wilson, DOC’s senior ranger for Auckland Inner Islands, said the date of a pest’s arrival on an island is usually not known, so the date of the first detection of its presence is recorded.

Unconfirmed pest sightings on islands in the gulf included three rats, three stoats, one mouse and one cat.

Two boat wrecks, one on August 21, 2017, on Rangitoto and another on April 24, 2018 on Atihau Island, resulted in precautionary searches for rodents. None were found.

Some of these unconfirmed pest sightings cost DOC a total of $79,992.