Heat map shows predator hot spots

A new “heat map” has been produced to show the hot spots in the ongoing war against predator mammals at Cornwallis (Karanga ā Hape).

A control programme targeting rats, mice, stoats and possums has been running on the peninsula for over eight years now and was recently extended to include the land west of the Kakamatua Inlet.

The total area under control is 310 hectares, of which privately owned land and dwellings makes up just 10%.

In the last 12 months to 31 March 2023, they were1804 trap “hits”, of which it is estimated that:

• 1671 were rats
• 27 were stoats (including 4 weasels)
• 79 were mice
• 21 hedgehogs.

This compares with 1318 hits for the 12 months to 30 Sept 2022. The large increase can be credited to the increased number of traps now activated in the land west of the Kakamatua Inlet.

The heat map shows the key battleground areas, where trap activity is at its highest. Some activity is still being recorded at the southern tip of the peninsula on Puponga Point, the location of the grey-faced petrel colony, however control programme organisers believe the predator threat is under control there and petrel colony is now slowly growing.

With fewer rats, stoats and mice on the peninsula, invertebrates such as weta and the numerous bird species (including penguins and grey-faced petrels) that were once prolific in the area, are beginning a slow recovery. At least a third of local fledgling petrel chicks are estimated to make it through to adulthood, which is considered good for a land-based colony.

The control work is being carried out by local community group SCOW, which originally formed to “Save Cornwallis’ Old Wharf”, but now works to help maintain and upgrade assets throughout the peninsula. This includes helping with such issues as removing graffiti from the wharf, communicating with Auckland Council on stormwater drain clearance and lobbying for better footpaths along Cornwallis Road.

A sub-group of SCOW, known as the Petrelheads – due to its work in protecting the grey-faced petrel colony on the southern tip of the peninsula – is currently organises the control work, with generous financial support from The Trusts, the Waitākere Ranges Local Board and Auckland Council.

Alex Duncan of the Petrelheads says they are indebted to those people who regularly check trap lines each month or so, but they are also looking for more volunteers to help with this work. If you are interested, you can email pestfreecornwallis@gmail.com for more information.

The Petrelheads work alongside a similar team in nearby Huia that is also doing predator control work. 

Cornwallis Wharf repairs complete

Cornwallis Wharf is open again, seven days a week, following the completion of major repairs.

The wharf had been closed much of 2021 while the repairs took place.

Items that have been replaced as part of the $25,000 upgrade include:

• replacement of damaged or rotting floorboards
• two new sets of wooden stairs from the wharf to water level
• a new landing platform for boats at wharf's far end 
• replacement of damaged or broken hand rails
• replacement of damaged or broken safety rails.

Many of the hand rails had been damaged by people fishing over the years, as they cut up bait on the wood leaving deep cuts and gouges in the top of the rail.

The funding for the repairs came from the estate of a west Auckland resident, who left $50,000 to be spent on wharf maintenance. 

The remainder of the generous donation is expected to be spent later in the year on waterblasting and minor repairs. Those repairs will be the third and final phase of the current wharf maintenance work.

Auckland Council is asking users to respect the wharf as a valubale community asset, and avoid further damage to its strucutre and safety features.

The reopening of the two sets of stairs has been especially welcomed by wharf users, as these had been closed for safety reasons for many years.

The repairs are the second phase of an expected three phase project.

The first phase was completed in 2020 and involved work to wrap Cornwallis Wharf's wooden support piles in a strengthening tape (as shown in photo).

Each wooden support was wrapped in industrial Denso tape - which can be applied underwater to give greater protection to the aging wood.

Much of the work at the eastern end of the wharf was done by trained divers as the tape can be applied underwater.

The first phase of the work was funded solely by Auckland Council and carried out by STG Group – specialists in marine construction and maintenance.

It was started in March 2020 and then paused for five weeks during the Covid-19 nationwide lockdown period.