An update by Ashleigh Olgilvie-Lee

‘For over 200 hours, a team of devoted volunteers has been waging war in Jasmine Valley; that stretch of paper road beyond Tenetahi Road which leads to Leigh Cove, so beloved by all discerning locals.

Who could have known when this English immigrant was brought to our shores with its intoxicating scent and exquisite little white flowers that it would turn into a rampant mass murderer, climbing up and strangling our magnificent natives. Although great in size,
our trees are no match for the stealthy ways of this invader which calls in reserves of blue morning glory, Japanese Honeysuckle, and moth plant to try and wipe out the rightful inhabitants of our New Zealand bush.

Jo Evans, Sue Gibbings and our other volunteers have managed to defeat these invaders in some battlefields which shows that victory is possible and sustainable with careful management. Where the
enemy has fallen, there is a noticeable demarcation zone and our trees are rising again from near death.

There really is great enthusiasm down in the cove at the moment as victory is within reach.
If you are in the area, do listen for the sound of secateurs snipping the strangling vines, Niwashis slashing the nodes and the trees sighing with gratitude at the valiant efforts made on their behalf.’

Ginger Control

Kahili ginger has also been on our radar. We have dug out mountains of rhizomes. These don’t break down too well in the black polythene bags. Auckland Council have provided a large drum and have recommended submerging them in water and sealing the lid. This eventually makes a slurry which can later be poured onto the soil. This is also an effective way of getting rid of mothplant pods.

We have purchased some native trees to replace those that haven’t survived strangulation by Jasmine. Auckland Council have provided us with 100 ferns as well as mulch and we have eco-sourced a variety of native plants.

We will soon be advising our volunteers of a planting day to get all these safely planted.

An account of our working bee held on 28 July through the eyes of Ashleigh Ogilvie-Lee

The morning glory, tradescantia and jasmine were trembling in their roots as, in true pioneering fashion, a dozen or so Leigh locals descended on them armed with gloves, secateurs and rakes. There is an extraordinary satisfaction in reclaiming the forest floor and I felt I was in a real life version of Minecraft, attacking the enemy using real not virtual strength. There is also a degree of cunning in hunting down the famous jasmine nodule which Neil said must be found if we want true annihilation of this particular enemy which released its venomous perfume in a futile attempt to pretend it was a good guy. I have to admit nodule detection was not my forte and I fear many wounded Jasmine clumps might recover to climb again and they will all rise from my patch; as the other volunteers had an air of knowing what they were doing.

My enthusiasm however more than compensated. There is pure joy in pulling jasmine off a native tree that it is ruthlessly strangling to death and the tree sometimes springs back in joy at its release, if it’s not too far gone. There is the same sense of heroism in discovering little ferns quivering under the tradescantia. One group of us worked from the top of the road and one from the bottom of the garden and at one point we reached each other in a real “Doctor Livingstone I presume” moment.

We had pies for lunch as a reward for our sterling performance and there really was a marvellous camaraderie in sharing our battle stories. There were, I’m pleased to say, no injuries amongst the true and brave but at least 10 weed bags full of fallen villains.

Update – June 2024

We were very fortunate to have the support of Kerryn Johnson and her pest detection dog Pip for 3 full days in May. Kerryn helped to rearrange several of our trap lines. Our aim is to more aggressively target stoats and we have redeployed some of our DoC traps on the borders of the bush and added modified Victor stoat traps. Having said that, weasel numbers appear to be high at present, suggesting there aren’t many stoats around. We certainly had more luck catching them in the early stages of the project. We have caught 10 weasels in a month and possibly more in the AT220’s.

We heard that Forest Bridge Trust have been catching quite a few stoats in the surrounding area. Stoats have a large home range, so this is also great news for Leigh.

Our volunteers Chris and Keith have now recharged all the AT220’s and topped them up with bait so they should be ok for another 3 months.

Madeira Vine and Kahili Ginger control

Madeira Vine
Please keep and eye out for Madeira vine, also known as Mignonette vine which has been seen in the Cape Rodney area. This climbing vine is very hard to get rid of once established and can strangle large areas of native trees.
Mignonette vine • Weedbusters
Madeira vine (tiakitamakimakaurau.nz)

Kahili Ginger
Another invasive pest plant on our radar is Kahili ginger. Over the Easter break volunteers helped to control a large area of this weed. It was evident this was the seed source of seedlings popping up around the bush block.

Community Weeding Day

A group of 10 dedicated volunteers met on Sunday, 24 March to carry out weeding on the Leigh foreshore. The plants are thriving but will be smothered by kikuyu and other weeds unless regular control is carried out over the next few years. If you happen to be walking past, please feel free to do a bit of weeding and place them in one of two composting bags provided. The mulch created in these bags will be used to provide nutrients to the plants along with moisture during the summer months.

Working Bee in Valley

Our first official working bee for 2024 was a huge success. On Sunday, 10 March, 12 enthusiastic volunteers met at the top of the catchment and set to work gathering up patches of tradescantia which were starting to creep back towards the stream edges. While the tradescantia leaf beetle is helping to suppress this weed in some areas and groundcovers including oplismenus hirtellus and pratia angulata are becoming established, the tradescantia still needs to be controlled.

After spending approximately an hour in one location, we gradually moved downstream collecting further patches along the way.

This is something we have been planning for ages but haven’t been able to carry out due to the very wet weather in 2023. Everyone agreed it was a very rewarding morning’s effort.

Bringing in the experts from Forest Bridge Trust

Bat Monitoring

On Friday, 23 February 2024, we were very fortunate to have input from Virginia Moreno, Ecology & Biodiversity Advisor, Forest Bridge Trust, who visited the valley to instal three bat monitoring devices. We have previously carried out bat monitoring using a hand-held device which indicated there was no bat activity. However, Viriginia advised the presence of bats is determined by a number of variables including the weather, temperature and availability of invertebrate prey and they might still be visiting the area. These automatic monitors which were positioned in two locations along the stream and on the border of the bush, will provide a more accurate record of bat activity over a period of weeks. Virginia plans to return to the bush with other members of the Forest Bridge Trust team to carry out a night time herpetological study. We look forward to the results of these investigations.

AT220 Data gathering

On Monday, 11 March, Hamish Stewart, Predator Control Assistant, provided an excellent training session on gathering data from the AT220 self setting traps. While we had been advised to count the rats carcasses or tails of decomposed rats to determine the number of strikes, these devices can do so much more. The data Hamish downloaded from one device indicated it had caught 5 possums and 12 rats whereas our data collection had indicated the machine had only caught 6 rats. Clearly this is a more reliable method of recording as often carcasses are carried away by scavengers including feral pigs. Hamish will be reviewing all our AT220 traps to ensure they are fully operational, and downloading the data.

We are most grateful to Virginia and Hamish for their valuable input and to Forest Bridge Trust for providing us with these experts in the field.

Weed Warriors making progress on Cape Rodney

Our team of dedicated volunteers continues to make strides in restoring the native bush and bird life. Along with managing phase 1 of our pulse baiting programme, we have been continuing to focus heavily on moth plant control. This weed is a master of disguise but much easier to detect when it is flowering. The aim has been to target the larger vines before the flowers form into pods and disperse their seeds. We have established bait and trap lines in some of the worst affected areas which means we can regularly monitor and control this evil climbing weed, along with some of the other nasty strangling vines. Large groves of tobacco plant and Queensland poplar are also on our radar. Landowners have previously employed contractors to manage this weed infestation in one area and the landowners themselves have also been carrying out regular control.

On Saturday, 17 February we set off at 7.45am, joined by Maria Sinclair, a secondary school Biology teacher from Whangaparoa College who has had lots of weeding experience and is a member of STAMP (Society Totally Against Moth Plant.) Maria, Richard Taylor, and Troy Taylor scaled the steep slopes like mountain goats finding previously missed vines, including an extremely large one which had reached halfway up a large macrocarpa tree. Lots of pods had already formed and, where possible, these were collected. This will be an ongoing battle but one we are all determined to win!

Moth Plant and Climbing Asparagus Control

25 volunteer hours of moth plant control have been carried out over the first 2 weeks of January. The aim is to remove the vines before the flowers turn into pods.
This weed is a massive problem in the Leigh area and we are working in conjunction with Coastal Care group and STAMP to control as many large infestations as possible.
Conservation Auckland – Moth Plant status

Moth plant

We have also been continuing to clear climbing asparagus to ensure the seeds don’t get dispersed by birds.
Conservation Auckland – Climbing asparagus status

Climbing asparagus

Both of these strangling vines can cause canopy collapse of our precious forest remnants if left to take hold.