Bream Head Reserve from Manaia

Rangers Report September 2021

We have had such a busy, productive month this September, there has hardly been time to take a breath!

Kia ora mai koutou,

Even with more lockdown roller coaster antics the team have been able to continue with the important mahi of protecting the gains made and adding new systems to our network. I am very proud once again of our rangers and volunteers who continue to work with such determination and dedication. I am also really stoked to hear so many birds, particularly over the south side of the reserve lately, such as korimako (bellbird) and kaka calling and singing their little hearts out, I think its directly related to the excellent Kowhai and rewarewa flower bloom this year!

Tracking Numbers

The 150 permanent tracking tunnels were fired up again in September to attain the 2021 spring residual tracking index for rodents at the reserve. Our fine team of rangers and volunteers Tony Climie and Grant Stevens set out the ink cards in the tunnels for a night and retrieved them the next day. This spring’s RTI was as follows: Rat 1.3% (+/-1%), Mice 34.67% (+/-5%) and weta 32.67% (+/-6%). This gives us an average RTI of 1.65% for the first 9 months of the year. Hopefully we see another 0% rat index in December which would give us an annual average rat RTI of 1.1%.

Even with this slight rise in RTI for rats the uptake of our rodent toxin continues to back off now after the autumn/mid-winter spike and we are really enjoying only having to use a few grams of the Double Tap toxin per station. This has several benefits such as less weight for us to carry and less toxin on the reserve! We continue to see a few predators sneaking in via the coastal predator run line at Ocean Beach and our new intensified trap line we have called “Load the Road” along Ocean Beach Road is already catching several predators, especially at the very end between Ocean and Proctors Beach. There is more about Load the Road in the full report.

Not Busy Enough

During September we decided we were not busy enough (sarcasm) and decided to also conduct a full, reserve-wide toxin programme targeting trap shy stoats with a direct feed toxin operation utilising a relatively new toxin known as PAPP (para-aminopropiophenone). This technique has not been widely used in New Zealand predator control thus far, especially in Northland. Our operations team decided we would trial the toxin and monitor as much of the animal behavior of stoats with the approved method of delivery into rodent tracking tunnels. This decision was based on trying everything we could do to protect this year’s GFP chicks and our strong belief in utilising as many tools in predator control as we can. Our capacity to monitor was quite limited but we had five trail cameras watching the tunnels 24/7 recording any stoat interaction with the devices and the PAPP fresh mince meatballs inside. Our passionate young ranger Keith Townsend talks more about this operation and its outcome below.

Mop-Up Detection Devices

We have also got the green light to start the install of the mop-up detection devices as part of the Predator Free Whangarei (PFW) Possum eradication project. The Trust has a contract with NRC to install these devices and monitor them going forward. More detailed information about this project will be included in my October report. September saw the completion of the first PFW contract the Trust successfully bid for, and that involved cutting trap line tracks and the installation
of knockdown devices for the PFW project on a large rural property on Taurikura Ridge. Led by the amazing Trustee and local legend Geoff Pike, two local hapu members helped Geoff with the mahi and the network of possum kill devices (1 per hectare) is now in place, all waypoints identified and ready to go. This was a massive operation for Geoff to supervise, learning new skills and being committed every day for over one month, and always with a smile of course – a huge thank you Geoff for your time and thanks also to Kruger and Ngawaru for your mahi. Congratulations on such a good job!

More Mahi

This month saw other important tasks and activities achieved such as:

  • GFP site predator control and monitoring equipment checks.
  • More volunteers signed up and inducted
  • Hut and Track maintenance by our super volunteers
  • Bait bagging again – Thanks Roger Clarke!

September Trapping Update

by Keith Townsend

L2 saw us back on the reserve. My mahi in September consisted of catching up on overdue mustelids trap lines on the south side, reserve boundary, and buffer. I didn’t catch any more than I would in a regular 2 week period, so demonstrating the importance of quality lures changed regularly. We have now swapped back from hen eggs to salted rabbit to mimic the natural food availability to a predator in the wild.

During these September trap checks we installed PAPP across the reserve, a toxin that targets stoats and feral cats. Alongside all our DOC200 boxes, black tunnels were placed which housed a rabbit mince lure encasing the toxin. Historically, the success of these kinds of operations have been hard to measure. It requires a stoat to find a bait within a few days of it being installed and eat the fresh rabbit mince lure and the toxin injected inside before it degrades in the field. Salted rabbit mince would last longer but a stoat would be deterred once it tasted the salty lure and not ingest the toxin within. We suspect this operation had little impact as minimal uptake was observed (difficult to tell from rotten bait remains) and no target species interactions were recorded on the few trail cameras we had monitoring the tunnels. But we had to try, and it’s possible that a stoat (or stoats) did in fact receive a lethal dose without eating the entire bait. Without trail cameras on every device the data is inconclusive.

Trail cameras really are the future for pest control and species recovery monitoring as they provide so much valuable information. We plan to get as many out on the reserve as we can to help inform management decisions. Already we have several installed at the grey faced petrel monitoring sites and other critical locations. But a reserve wide lured trail camera network purely for detection is the dream. Don’t worry, it’s starting with install of the Predator Free Whangarei possum surveillance gear and our own funding applications. Until then, we don’t know what we don’t know. But if you have any spare dollars looking for a good home how about making a donation tagged to trail cameras and we will get further down the track of realising our dream.

Read this month’s Rangers Report in full for more from Keith and other local stories.