Lizards on the escarpment – May 2017
Written by Paul Callister
‘The more surveys I do, the more I realise we’re looking at the wreckage of populations’, Trent Bell, Ecogecko, 2017
Twenty years ago, when Ngā Uruora began, lizards were not high on our agenda. It was the Kohekohe forest remnants we wanted to protect from possums and sheep and we also put much effort into planting some areas of the Paekākāriki-Pukerua Bay escarpment. Bringing back the birdsong was – and still is – a key objective. So we started trapping possums and we began to fix the fences to keep sheep out.
As time went on we became more aware of the need to control mustelids and rats so traps and bait stations targeting them began to be laid out. Slowly we constructed new and better tracks so the trapping networks were improved. Research made us realise hedgehogs were also a problem.
Over many years of working on the escarpment a number of us have been puzzled as to why we saw so few lizards. There have always been plenty of skinks in home gardens despite there being many neighbourhood cats. Lots of common skinks in town but very few seen on the escarpment. Gecko sightings on the escarpment had never been reported. Yet geckos are commonly seen in urban areas of Pukerua Bay.
In the last two years, Ngā Uruora’s inclusion in the Ministry for the Environment funded Kāpiti Biodiversity Project has not only allowed us to further increase our trapping network but it has provided an opportunity to undertake some research on lizards. Ecogecko, and in particular Trent Bell, has led this research effort.
Gaining additional funding at this time coincided with the completion of Te Araroa’s escarpment track which has improved access to our trapping network.
In 2012 the Wellington Regional Lizard Network had published a lizard strategy for the Wellington region. The report brought together the views of lizard experts along with a variety of other stakeholders, including the Department of Conservation and local authorities.
This document informed us that lizards are New Zealand’s largest terrestrial vertebrate group with more than 100 species. They should occupy almost all available ecosystems from coastal shores to mountain peaks. It informed us that lizards play an important role in ecosystem processes and function as predators, pollinators, frugivores and seed dispersers.
The report also argued that lizards are emerging as iconic flagship and indicator species in conservation and ecological restoration. And despite most of this fauna currently being threatened or at-risk, lizards can be exceptionally abundant when released from mammalian predation pressure. Just visit Mana Island, not far from the escarpment, to see the effect of getting rid of predators on lizard populations.
The lizard strategy painted a picture of significant lizard diversity in the Wellington region. A variety of lizards should be abundant on the escarpment. Ecogecko suggests we should have populations of Ngahere gecko, Northern grass skinks, Barking geckos, Ornate skinks, Copper skinks, Brown skinks, Spotted skinks and Raukawa gecko. Many years ago we probably had Whitakers skinks. Some of these species live on the ground, some in trees.
Photo courtesy of Ecogecko
Unfortunately through predation and habitat change all lizards have been under extreme pressure. Historically much of the escarpment would have been burnt and grazed with sheep and cattle. Predators include rats, mice, hedgehogs and mustelids. Habitat change can also include areas of former scree grassing over. Yet despite our habitat being degraded for a long period, there still remains good potential habitat, including rocky outcrops and large patches of the native plants Propinqua and Muehlenbeckia which are favourite food sources and habitat for lizards.
In 2015, at the start of the MfE project, two predator control reports were prepared to guide the increased predator control on the escarpment. There was a report setting out how there would be the creation of a wider ‘Kāpiti Mainland Island’. This was followed by a more detailed operational report for Ngā Uruora. A lizard strategy report was also prepared to help guide the lizard research (all reports are available on the Naturespace website). At this point there was a lack of information on the best ways to support local lizard populations aside from the standard ideas of increasing overall predator control.
In summer 2016, Ecogecko and volunteers undertook surveys at both Queen Elizabeth Park and Whareroa Farm Reserve. Ecogecko also led two small surveys on the escarpment. A report summarising the findings was then prepared. Not only did this report set out a list of lizards that might be expected to be found in the area, but what was actually found and some recommendations for further study. It also gave some ideas for enhancing predator control, especially in relation to mice on the escarpment. While some lizards were found on the escarpment, it was clear from the survey work that mice were common and likely to be impacting lizard populations. It has also become clear from autopsy work carried out by veterinarian Sue Blaikie on locally trapped rats and mustelids that lizards formed part of the diet of rats and mustelids.
In mid-2016 a predator control workshop was held bringing together the local predator control community. A key theme was how to support lizard populations with a particular emphasis on controlling mice.
At this workshop, Ecogecko set out their ideas for mice control. In addition, Angus Hulme-Moir explained what the Friends of Whitireia Park were doing with their lizard protection trial.
Following the workshop, Ngā Uruora began exploring setting up a lizard protection trial on the escarpment. This included gaining a lizard handling permit. Angus Hulme-Moir, in his role at the Department of Conservation (DOC), has been especially helpful in setting up this trial. We have also received much helpful technical advice from DOC and from lizard experts at Victoria University, including Sarah Herbert. Ngā Uruora and the Department have a Memorandum of Understanding to help ensure ongoing support. Quite a few of Ngā Uruora volunteers have undertaken lizard training so we can legally handle this protected species. Our work is being carried out under a permit issued through the ‘Wildlife Act Authority for wildlife on non-public conservation land’. The approval defines the activity: live catch of lizards, the methods allowed (onduline, pitfall traps, foam covers), how they can be marked, the land area covered, and the personnel authorised to handle lizards.
Over summer Ngā Uruora volunteers set up this trial in the middle of the escarpment. Very appropriately, the trial site is directly below the memorial seat for ecologist Geoff Park. Geoff’s book Nga Uruora provided an inspiration and a name for our group. A number of working bees were held and following people assisted: Jim Hammond, Chris Keating, Jean Fleming, Tony Older, Sue Boyde, Glenda Robb, Liz Johns, Andy McKay, Paul Callister, Peter McLaughlin, David McKay, Michael Bennett and Vicky Griffin.
People walking the track will have seen lots of bamboo stakes popping up on the slope with pink or orange triangles on them. They might have also seen volunteers in high viz gear clinging to the side of the hill.
We are grateful to the following people who took part in this initial monitor: Trent Bell, Glenda Robb, Jina Sagar, Marian Cox, Andy Mckay, Bob Zuur, Peter McLaughlin, Sue Boyde, Paul Callister and Michael Stace. The weather was challenging for this first monitor as the weekends were either side of the remnants of cyclone Debbie. While the number of lizards found was disappointing, it was not unexpected. It reinforced why we are doing this trial, to create an environment where they can thrive.
We have just completed our first lizard monitor. Eight days checking over two weeks. We found 5 Northern grass skinks and two Raukawa geckos.
We have now begun the intensive predator control. We are using the Goodnature A24 traps as well as backup bait stations. In the area we will also have some remote sensed traps with the sensors designed by the startup company Econode. These send signals out to an aerial installed on Tokomapuna Island (Aeroplane Island) through a joint venture with local firm Groundtruth and Karl Webber. These signals then show us through the internet when the traps have gone off.
This site is within a larger area of pest control and we are grateful to our volunteer trappers, the Greater Wellington Regional Council who have supported our pest control for many years and the Kapiti Biodiversity Project which has funded an expansion of our trapping effort including supporting this lizard trial. We are also grateful to Friends of Whitireia Park who are loaning us some A24s.
Soon we will install a sign above the trial area explaining what we are doing. Again this is funded by the Kapiti Biodiversity Project. This sign will be similar to other signs along the escarpment installed by Te Araroa Wellington Trust. We were so impressed with the quality of these signs we asked the designer of those signs, Isobel Gabites, to also design our sign.
We aim to run this trial for at least five years and hopefully ten. At Ngā Uruora’s 30th anniversary (in 2027) we hope we can report that lizards on this part of the escarpment are once more abundant. We want to turn the ‘wreckage of populations’ into vibrant healthy communities.
If you want to learn more about this trial you can download our draft lizard protection trial document from Naturespace.
Since we started focussing on lizards some of our trappers are also now reporting more sightings. It’s partly that we now have a better idea of what to look for. In particular the common Northern grass skink can often be spotted basking on warm rocks at what we call the ‘quarry’ opposite Fisherman’s Table. We have seen common geckos here too resting under onduline.
We have also put tracking tunnels at the quarry and have recorded lizard footprints.
Predator control has been going on for quite a number of years in this area, plus the rocky screes seem ideal for some lizards. We have also upped predator control in this area to help sustain and increase these lizard populations. Again using A24s is part of this.
We will also place onduline sheets (small squares of roofing that lizards can live under) in other places along the escarpment to undertake informal monitoring. We are grateful to Waikanae’s Menzshed for cutting up this onduline for us.
To help make the escarpment a great place for lizards we need help in various ways. We are permanently on the lookout for new volunteers. Donations to help cover our running costs are always appreciated. Go to https://givealittle.co.nz/org/ngauruorakapiti/ If walkers on the escarpment spot any interesting looking lizards, take a photo and send us a copy with an indication of where it was found (send to email@example.com with ‘lizard’ in the subject line).
We will continue to report how we are doing via our Facebook page and newsletters.