Project News

Rangers Report April 2023

Rangers Report April 2023

Operational Summary

It’s been a busy but wet few months! We hope everyone is well. As always, thank you to all of our supporters, volunteers and fellow community groups! This report covers March and April 2023. 

Key points:

  • Increased toxin uptake by rodents after switching from pindone pellets to ratabate (diphacinone) paste.
  • Catch rates of rats, mice, stoats and weasels remain consistent over the past four months.
  • Post-cyclone cleanup of toxin/trap lines is progressing nicely.
  • Grey-faced petrels (Ōi) have recently returned and are in the early stages of mating.
  • Community planting day will be held on the 11th of June with a back-up date of the 18th of June.
  • Weed of the month is wild ginger.

Predator Control

For the past few months, rangers and volunteers have been switching pindone out pindone for ratabate (diphacinone) in bait stations. There was an immediate increase in bait uptake by rodents. Uptake of ratabate has been quite high over the last month (~75% overall). Uptake on the southern side of the Reserve has been slightly lower than the northern side. The northern side of the Reserve has more bait dispersed across it, as we have prioritised clearing tracks on this side first. Pests most likely invade the Reserve from the north. This theory is supported by the fact that we catch a lot more pests towards the north. These are likely the reasons for why toxin uptake is higher on the northern side of the Reserve. 

We caught 29 rats in March and another 29 in April, mostly ship rats, and mostly outside the reserve. Trapping results tables are in the full report.

Advanced Camera Detection

Much like the months January and February, not all cameras were serviced during April and May. We have prioritised clearing our trap/toxin line tracks in the months following the cyclone. This has pulled ranger time away from getting all of our toxin lines done each month. In turn, this has meant some cameras have been missed. I say this because an analysis of current camera data may not be an accurate representation of what is happening out on the reserve.

Judging from the data we have received from Hadden at Predator Free Whangārei, there have been many Kiwi show up on the cameras, along with a few troublesome stoats. There was one possum sighted on Busby Head during April. The few possums we see on the cameras usually end up being caught in our sentinel traps or PFW’s live legholds, eventually.

Grey Faced Petrel (Ōi)

At the Grey-faced petrel (Ōi) study sites on J line there are clear signs birds are back prospecting. Breeding birds return to the site from early February but primarily in April/May to re-establish pair bonds, prepare burrows and mate. Tom reports that the burrow preparation has begun in earnest, with debris spread far and wide. These burrow roadworks remind him of driving to work along Whangārei Heads Road!

We will be closely monitoring these sites again this year and do all that we can to protect them over their nesting season.

The results of last year's nesting season left us very disappointed as most chicks were predated by stoats before fledging. We did everything we could to keep the stoats away from these nesting sites, but it is clear that we need to do more if we want to get rid of mustelids. We will be searching for, and trialing promising methods for mustelid control as they become available to us. 

Interesting Finds (Horopito and Rata)

On the last Friday of April, rangers David Lawrence-Solomon and Tom Flynn-Plummer went with Andrew Townsend (botanist and technical advisor at DOC) to check on one of the rarer plant species on the reserve - the Northland horipito (pseudowintera insperata). The top peak of Te Whara is one of the few places where this plant still exists. Fortunately, the plants were looking good. They had survived the cyclone and the other recent weather events. We noticed that a few juveniles had died, but this was most likely due to the previous years drought conditions. Andrew was also interested in disproving an apparent theory that no Northern rātā (Metrosideros robusta) remained in the reserve; after a bit of a hunt, we found a grand old specimen still going strong. There are likely a few more large individuals that were spotted from atop Te Whara, but we only got to the base of one.

Community planting day at Home BayWritten by BHCT ranger Tom GrinstedBring your whānau and friends, and join others in our community. Help plant 2,500 plants to increase habitat for our local biodiversity.When:Sunday 11th of June, 9am to 12 noon. If it's raining, the event will not proceed*.Where:At 8:45am, meet at Urquhart Bay car park for a briefing. After 9am Follow the track past the gun emplacement to Home Bay where you will find us.What to bring:Warm clothing, gum boots or solid footwear, raincoat, water etc. Your own spade if you have one. Hot drinks and kai will be provided.Back up date:Sunday 18th June 9am to 12 noon.If we don’t plant all plants on the 11th or if we need to postpone due to wet weather, this will be communicated via our Facebook page and email.

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