Polhill’s exciting discovery : a Saddleback / Tieke nest.

I thought it was time that I updated you about what we have been up to in Polhill and what is planned for the coming months. The most exciting thing to happen recently is that we discovered a saddleback/tieke nest near one of mountain bike tracks and working closely with WCC and Zealandia we soon identified that there were two eggs – closely followed days later by two chicks. What is remarkable about this is that until 2002 tieke were extinct on the mainland of New Zealand and critically endangered, residing only on a very small number of offshore islands. We are now seeing and hearing tieke on a regular basis and it is estimated that Polhill Rerserve could support a population of 300 birds with intensive trapping.

Tieke nest with chicks Photo Bernard Smith

Tieke nest with chicks
Photo Bernard Smith

We are now monitoring the nest site with the help of Matt Robertson, Park Ranger at WCC and staff from Zealandia, and with the support of WCC we have also placed additional traps around the nest to help protect the chicks from rats, weasels and stoats. This is incredibly exciting and we hope that with the extra protection provided by this “ring of steel” we can see these birds fledge and join the growing population of these beautiful and once rare birds.

Saddleback Photo Paul Ward

Photo Paul Ward

Our three trap lines are being serviced by teams of keen volunteers and we have been catching a steady stream of rats, hedgehogs and weasels – with possibly our first stoat caught a few weeks ago. For some reason it has been quiet over the last couple of months. We are experimenting with recording our trap catch data using a new web based tool www.trap.org.nz a great website developed by local Kapiti Coast company, GroundTruth Limited, part funded by WWF-New Zealand and now part of Predator Free New Zealand. We still need to do some training to ensure everyone can use it, or alternatively people can email me their trap results and I will fill it in.
New Traps
A while ago we were donated three A12 self-resetting possum traps and four A24 self-resetting rat/stoat traps – both designed and manufactured by Goodnature. These have now all been placed in the reserve – one near the newly discovered tieke nest. We also secured two extra DOC200s and about five Victor Professional rat traps to use around the nest.
Following our successful chew card monitoring exercise last summer, which showed us we have more pests than we might have thought based on the trapping results, I have been looking into simpler, easier to repeat techniques to monitor both predator numbers and also the breeding success of native birds in the reserve. We applied for two grants through the WCC Our Living City Fund – and were successful in getting $1000 for predator monitoring and $3075 for bird breeding success monitoring. Thanks to Aro Valley Community Council who agreed to be our “Umbrella Group” for the first grant, and Wellington Natural Heritage Trust who are our umbrella group for the second grant. Thanks to WCC for supporting our project.
Tracking Tunnels and chew cards
For the predator monitoring we are now going to use the well-established method of using tracking tunnels with ready inked Black Trakka cards to detect footprints of critters – good and bad! This involves laying out 6 lines of 5 tunnels, 50m apart, throughout the reserve on a semi-permanent basis. The tunnels are a robust plastic and are left in place for some time on the permanently marked lines. The cards are only placed in for between 1-3 nights to monitor the footprints. This then gives us a % “tracking index” based on the number of cards with footprints. 5% is the magic number for rats, below which many forest birds can successfully breed. We were donated 30 tracking tunnels by Goodnature and DOC, who are keen to try monitoring in urban reserves. WCC is also keen to use the reserve and our monitoring to trial the use of chew cards along the same lines. From this it will be possible to ‘calibrate’ the accuracy of chew cards to give a tracking index. Chew cards are easier for volunteers to use, and also have the advantage of showing possums (& hedgehogs). We will need volunteers do the monitoring once the tunnels have been laid out.
Bird Nest Monitoring
Our grant for bird nest monitoring will buy us three trail cams and assistance from experienced and trained bird monitoring folk, Annette and Delia to help us find nests of our four ‘target’ species – North Island robins (toutouwai), saddleback (tieke), kakariki and kaka.
Kaka Nest Box and monitoring
As part of a city wide experiment DOC has chosen Polhill to locate a kaka nest box in the reserve, to see if kaka can nest safely outside Zealandia in reserves with ongoing volunteer predator control. The box has been sited at a secret location – and we need volunteers to agree to monitor the nest for signs of use and then check it regularly if kaka start to use it. As yet no one has claimed this des res as home. It might take a year before a bird finds it and decides to take up residence.
Morgan Foundation Camera trial
Following the high profile Morgan Foundation garden camera trial, the Foundation lent the trail cams out to a number of groups to place in reserves. We were lent three, and I placed them in locations in the reserve near either traps or bait stations. We left the cameras in the reserve for three weeks and then recovered them, downloading the images from the SD card. They made for interesting viewing. The cameras (which have infrared night vision capability) detected a number of blackbirds, rabbits, dogs, dog walkers, rather strangely a family going “off track” but the highest number of images by a long way – both day and night – were of cats. It was impossible to tell if these were domestic or strays, but all three sites were a considerable distance from the nearest houses, showing that cats are either living in the reserve or domestic moggies are wandering over quite large distances. Interestingly No rats, possums, hedgehogs or weasels were detected.
If you are keen to help with any of these projects, get involved in some other aspect of the project such as recruiting volunteers, helping coordinate or have ideas of how we can expand the trapping to involve more households, schools or businesses please get in touch.

Coordinator, Marc Slade
021 0278 1556