Mostly just stuff I am doing to help the planet
With a lot more mowing at Point England this Winter the flocks of South Island pied oystercatcher are leaving a visible sign in the paddock. The probe holes are very dense right to the edges of the paddocks which means that I am also seeing holes from other species like White-faced heron and Pukeko. Casual counts put the number of little holes at around 100 per square meter.
Today I took photos of the shorebird roosts at Tahuna Torea when the tide had just covered the main spit roost. The tide height was predicted to be very high today (3 August 2019) at 3.4M Westhaven 8:53am. Conditions were relatively calm and the tide had not (yet) hit the high tide line on the Little spit.
I have seen tidal debris in the mangroves around Lockley Island that were above the height of the island (indicating that it sometimes gets swamped) but I think it would have made an ok roost today.
I was recently lucky enough to monitor kiwi on Hauturu with the Little Barrier Island Supporters Trust. I have done this many times before at Tāwharanui with TOSSI. The exercise involves a good hike to the destination at night then sitting quietly in the dark listening to the sounds of the forest for a couple of hours. I have met some great people doing this and this trip was no exception. They patiently waited for me as I inched along the tracks on the way back to the hut, inspecting every tree for hidden treasures and some even came out with me again on their free nights. I have posted all my invertebrate observations here on iNaturalist where the community is helping me identify them all. I have also posted some fungi which were a hot topic among the volunteers.
It’s an incredible island where one can get a sense for pre-human New Zealand. Here is a list of some observations I made over the 12 days I was there.
I presented this report to the Maungakiekie-Tāmaki Local Board today as they are yet to seek advice from a shorebird expert at Auckland Council in developing their Open Space Network Plan (OSNP).
It recommends:
I have also attached my amendments to the OSNP and my submission on the OSNP above.
UPDATE: 1 May 2019.
Great response from the Ōrākei Local Board, nothing from the Maungakiekie-Tāmaki Local Board (yet) who have approved their Open Space Network Plan with no space for shorebirds.
UPDATE: 18 June 2019
Great article on the report by Farrah Hancock here
UPDATE: 12 July 2019
“The report’s recommendations accord closely with the Council’s policies and objectives to protect biodiversity in the Auckland region.”
– Dr Tim Lovegrove
UPDATE: 01 September 2019
Report covered on page 9 of the Panmure Business & Community Newsletter
UPDATE: 12 September 2019
The MTLB have made changes to the OSNP as follows:
| Page/title | Amended text |
| Page 10 (Coastlines and Waterways) | The Tāmaki Estuary is home to a varied number of shorebird species. The shorebirds roost in the reserves along the coastal edge throughout the year including Point England Reserve, Wellington War Memorial Reserve and Tahuna Torea Nature Reserve. Several species are threatened and the populations are in decline. Threats to the shorebirds include disturbance of their roosts preventing them from resting, particularly at high tide, from lighting of the reserves at night, dogs, humans, unsuitable vegetation and construction. |
| Page 20 (Environmental Quality) | + Shorebird populations are in decline due to their roosts within the coastal reserves being disturbed |
| Page 36 (Improve biodiversity and water quality) | Protect and enhance shorebird roosting areas: + Investigate opportunities to restore roosting areas for shorebird populations + Provide opportunities to protect existing roosting areas. |
The wording is well chosen and at a high level it addresses my core concerns. A good start to reversing the decline of the shorebirds in the Tāmaki Estuary.
UPDATE: 7 May 2020
The authors have really taken on board the feedback! Shorebirds (which contain the most conservation dependant species in the region) were excluded from the plan. They now feature on pages 10, 21, 37, 51, 52, 55, 93, 94, 109. You can download the finalised copy of the Tāmaki Open Space Network Plan here. [Published here first!]
UPDATE: 20 August 2020
Ōrākei Local Board’s environment work programme 2020/2021: Tāhuna Tōrea investigation of habitat restoration for shorebird roosting $15,000
We identified 19 tracking locations (S1-S19) in 2014. The first 10 (S1-S10) were used in this survey. The survey was repeated in March 2019. The first 10 locations were searched and three out of 10 tracking tunnels were found. Seven new tracking tunnels were installed on the 10th of March. On the 16th of March another 9 tunnels were installed and all the tunnels were filled with an inked tracking card with peanut butter in the middle. Some locations were adjusted to make access easier. I noticed when trying to find the tunnels again with the Garmin InReach and App that the positions were often off by up to 16M. Thats a lot in the bush!
RESULTS
I find these mashed up prints very hard to identify, but here is my best guess:
S1 Hedgehog
S2 WW, Rat, Hedgehog
S3 Rat, Hedgehog
S4 Hedgehog, WW
S5 –
S6 –
S7 Hedgehog
S8 –
S9 –
S10 –
S11 –
S12 –
S13 –
S14 –
S15 –
S16 –
S17 –
S18 –
S19 –
WW = Winged weta, I was particularly looking for this species. See my blog post on tracking winged weta here.
I think we should probably ignore the tracking tunnels put out recently (S11-S19) as they may have been avoided due to (at at least some of) the target species being neophobic.
This would give us a result for 2019 of 20% Rat, 0% Mice, 50% Hedgehog. This indicates we have less rats & mice and more hedgehogs than 2019.
I have left the tunnels out there, it might be a good idea to retry in a few weeks. It’s interesting that we see more pests near the top of the bush, this has been observed before.
This was my most challenging project for 2018. After reading about the New Zealand Fairy Tern decoys I was making, the Mangawhai Museum approached me to make them some replicas. As there are only 40 of these birds left in the world they were never going to be able to get a taxidermy one for an exhibition.
I was very ambitious and decided to create a feeding scene where the male is landing with a fish in his bill. This was very challenging and I really pushed my printer to the limits and discovered a few new tricks in the process. I think this kind of model making has advantages over taxidermy where the models can be designed to exhibit a wide range of behaviours. It will be interesting to hear how the public react.
I think this is the worlds first photo of a freshly planted mussel bed. Altho I have been to most of Revive our Gulf’s deployments (including the first one in 2013) we have’t dived on them straight away. After taking this photo I deployed three time-lapse cameras to record suspected predation (I was happy to discover none). I also photographed a nearby bed that was laid a week ago where the mussels are standing up and had knitted together. It would be interesting to know how long it takes them to jostle into position.
I tried 3D printing this stencil for a penguin box so I didn’t have to cut out the letters. 5 layers at .2mm PLA. It worked great and the thin lines come out really well, but you can’t leave the stencil in the sun or it warps!
I have been counting a lot of birds lately trying to build a solid picture of how the shorebirds use the Tāmaki Estuary. In addition to regular wader counts I decided to try and also count them at night as they might use the roosting areas differently. After testing various devices including long exposure photography Pieter and I decided on expensive gear to do the survey, I bought a Luna Optics LN-DM50-HRSD Digital Night Vision Monocular (example image above) and Pieter purchased a Pulsar Helion Thermal Imaging Handheld XP38. Using these devices helped us count the birds without disturbing them which was quite important to us. Details of the trial here Tamaki Estuary shorebird survey – Wildlands.
The feeding observations were really interesting. Tho in regards to extra light – it was disappointing not to find shorebirds at Mt Wellington War Memorial Reserve where I found banded dotterel and flocks of SIPO at night last year. The reserve now has large lights for playing sports in the dark.
I think the trial study has given us enough data to understand how the shorebirds use the estuary at night. More detail would be interesting but is unlikely to affect future management decisions. Here is the Raw data. I plan to keep a better eye on the Pakuranga Sailing Club and include the data in a report to Council on roosting in the Tāmaki Estuary.
== SUPLEMENTRY NOTES ==
Access to viewing points was limited because we wanted to do the survey without disturbing the birds. All the waders identified were more easily scared at night with the exception of the mixed flock at the Pakuranga Sailing Club that was unusually calm in our presence (both day and night). Day counts followed the limited routes of the night counts for consistency, however a few birds were often seen during the day that would have been hard to see at night from the same vantage point.
No variations in flock shape were observed between day and night. The main thing that correlated with flock shape was if the SIPO were feeding. The SIPO flock spread out over 100m in diameter when feeding at Point England both on the sportsfeilds (at night) and the paddocks (during the day). The pied stilts were always grouped closely together.
I think the roosting patterns look like waders are primarily avoiding disturbance. Wide open spaces with no obstructions or light were preferred… maybe close to the water too – especially for the smaller waders? Seaside park a good example – I was surprised to see SIPO there at night. The lack of birds at Mt Wellington both Day and Night in 2018 vs 2017 is odd. Maybe the addition of the lights has also reduced the sites daytime roosting function.
I totalled the counts for SIPO and Stilts to see if there are variations in the total day vs night numbers. We are short 22.5% on SIPO, I feel like we would not have been that far off and some birds are heading elsewhere to roost, it’s not a huge number tho. I am sure we missed some birds tho, for example during the day the NNZD at Point England are so much easier to spot than at night.
After talking about my New Zealand fairy tern decoys I was approached by Australian conservationists about making decoys to attract Australian fairy tern. Although they are the same species they have brighter beaks and shorter eye patches so I modified the paint job a bit. The biggest difference between the sub-species seems to be that they flock together to nest. I imagine this will make the decoys more effective for this subspecies.
I lowered the design so it looks more like they are incubating, hopefully they will still turn into the wind ok. Photos below of the birds without spikes above and below.
We’ve had some problems with these decoys, the black painted parts get so hot in Western Australia that the plastic melts leaving the decoys with flat hair cuts! The glass transition temperature for PLA is around 60° C. I tried covering some PLA with two part epoxy resin then warmed it up to try and simulate the issue. The epoxy worked well holding the form in shape even when I got it so hot the surface burned. However it did deform a little with bubbles and spilts, this might work as a patch up job but its not ideal, other ideas:
1. Changing the plumage to be less black (juvenile)
2. Printing with more infill (thicker heavier decoy)
3. Printing with another plastic
4. Creating moulds and using resins
I really like using PLA because it’s biodegradable and from a renewable resource but in this situation it just might not be up to the challenge. Common filament options are: ABS (won’t print with as good detail), PET (not glue-able) or Nylon (which has a lower glass temperature). I could print with plastic that has better thermal resistance like Polycarbonate, or print using dissolvable supports and no glue with something like PET but I would need a much more expensive printer. Unfortunately I think heat resistant decoys are going to be less environmentally friendly and either expensive or labour intensive 🙁
Update May 2019
I have made three new decoys to test, all are glued using two part epoxy.
The numbers 1,2 & 3 are carved into the newly designed peg which is shorter but more heavy duty. The increased infill makes all of them heavier, this should help keep them down when the sand moves, if that does not work the painted legs should look more natural. The overall design of this decoy is a little more robust, it has it’s head ‘terned’ a little to help distinguish it from the other decoys I have made.
Update Dec 2019
These decoys were deployed from 3 Nov-20 December on Garden Island. They did not attract the target flock which nested elsewhere. With three of the days being in excess of 37 degrees the decoys got tested pretty well and show no signs of melting or splitting. They have been deployed in the researchers garden for further testing 😀
Update April 2020
Decoy 2 developed a minor crack in the join, it was the weakest decoy with half as much infill for internal strength. No changes to the other two.