Sunday, December 2, 2018

DOC’s latest fresh water fish survey.

Electric stun fishing does not kill the fish. 

The Department of Conservation’s new threat classification report for fresh water fish 2017 was released in August this year. There are three species that are found in the Mangaiti Stream system that have the “At risk – declining” status; giant kokopu, longfin eel and inanga, .
The giant kokopu (Galaxias argenteus) inhabits the ponding area in the gully below Sexton Road and has been found in the main stream. These tend to be active at night so are rarely seen. It was when Waikato Regional Council’s scientists were doing a fish survey using the electrical stunning method that they were located. Only one giant kokopu was recorded in the stream.
The Longfin eel (Anguilla dieffenbachia) has been mentioned several times on this website. The report noted that the decline in water quality in many areas has resulted in the shortfin eel (which has a “not threatened” status) occupying habitat that formerly held the longfin eel which suggests that the two species may be competing within a habitat or it could be that the longfin eel prefers better water quality. Either way it is clearly evident that the shortfin eel is the dominant species in the Mangaiti waterways. In the 2012 survey there were 2 longfin eel and 21 shortfin eel counted in a fifty metre length of stream. The longfin eel has a very long life and the ones we are seeing appear to be mature adults. The worry is that the population is not being maintained with juveniles moving upstream in their normal life cycle. 
In the 2012 survey, 29 inanga (Galaxias maculatus) were recorded. 
Planting the stream edge becomes all the more important when you are aware of the status of some of the occupants.

Book review

Rat Island: Predators in paradise and the world’s greatest wildlife rescue
By William Stolzenburg
Bloomsbury: 2011
ISBN 978 1 4088 2511 2
William Stolzenburg is an American journalist who writes a lot about animals, but for the past decade, his focus has settled on that particular class of creature called predators. Rat Island is one of three that he has recently published. The other two are: Where the Wild Things Were and Heart of a Lion.
Rat Island focuses on three main island groups; the Aleutians in the Bering Sea, (the group that run south west from Alaska), Clipperton Island which lies one thousand three hundred kilometres off the coast of Mexico and the New Zealand group.
He covers each group with a detailed back history that sets the scene for the full-on attack to eradicate the introduced predators. This is followed up with a description of the recovery of the particular ecosystem or indigenous species that was being targeted.
A large part of the book is focused on New Zealand. The work attempted in Fiordland in the 1880’s by Richard Henry, an early pioneer in pest management, and in the 1960s when Don Merton became actively involved as a junior in the Wild Life Service, all set the scene for the battle to recover Islands that were being decimated by pests. One of the big breakthroughs was the discovery of the single feed bait Brodifacom for the eradication of rats, which are the major pest and the most difficult to eradicate. This replaced warfarin that required high doses delivered over several feeds.
The work done in New Zealand influenced how island sanctuaries around the world managed their eradication programmes. Not all went smoothly. Each island had their unique features that had to be taken into account. There were cases of unexpected collateral damage to manage. Bureaucrats caused frustration then, as they do now. Islands close to urban areas had ill-informed protesters to deal with, but despite this, all had a successful ecological outcome.
The early chapters on the history of the ecological effect of human occupation on Aotearoa, which started seven centuries ago, should I feel, be included in the New Zealand high school history curriculum. We should all understand the ecological damage we have done in the past so that we can better manage the future.

This book is very well written and a really good read. Does it give you hope? I am not sure. Read it and see what you think. 

Willow (and Poplar) tree felling in gully

The finishing touches of felling a poplar

The removal of the grey willows from the gully in our restoration area has been a long process. The project was started because of the arrival of the Australian willow aphid in the Waikato a couple of years back. The aphid’s excretion (dew) causes a black mould that completely covers the understorey plants. Coinciding with the aphid’s arrival we experienced a massive population explosion of the German wasps that summer. These wasps feed off the dew from the aphids so the abundance of food may well have been responsible for this population increase. 
We have had a willow poisoning programme running for a couple of years now and this is ongoing.  We were getting concerned that the dead willows along the tracks were falling down and were becoming a safety concern so we applied for, and obtaining funding from Hamilton City Council Community Funding Grant to employ a contractor to fell the trees of concern. This funding has not finished the job so we have obtained further funding from Len Reynolds Trust to finish it off.

Upgrading the grip netting on board walks

With funding from Hamilton City Council Community Funding Grant we have replaced all the non-slip netting on the board walks to a commercial grade. The previous netting was that used to keep leaves out of the gutter on house roofs. While doing this work the boardwalks were also realigned where necessary. After poisoning and cutting down willows the exposure of the boardwalk to the sun has caused some warping.

The Mazda Foundation injects $16,000 into Waikato community projects

Eight Waikato groups, including three environmental groups, have been given donations totalling $16,000 as part of the Mazda Foundation’s latest funding round (they fund New Zealand wide). Our Trust was fortunate enough to receive $4,200 to support our pest eradication programme. This has set up our project on a very sustainable financial footing. Eradicating rats and possums is a crucial part of our aim to achieve a healthy population of indigenous biodiversity within the thirty hectares of the Mangaiti gully system. Mangaiti Gully Restoration Trust is very appreciative of the Mazda Foundation support.

Sunday, September 23, 2018

Bat house in Hamilton being used

Photo supplied by Kerry Borkin 

One of the highlights of the recent Bat Conference was the news that bats had been found using a roost box in Hamilton. There have been a number of roost boxes erected, mainly in the Hammond Park area in the south of Hamilton, but this is the first time one has been used. Overseas websites about bat roost boxes suggest that they can take up to five years before bats may occupy them. New Zealand bats, in this case the long tailed bat, are quite different than those overseas so it was unknown before now as to whether our bats would use them. This one in the You Tube footage was installed seven years ago.

This You Tube clip is a great bit of footage of bats exiting the roost box in Hamilton:

Longfin eels

Signs at each bridge encouraging people not to kill the eels
We have longfin eels in our gully system. The children up the Gordonton Road end of the stream feed them with raw cheap barbeque sausages. These eels get very friendly and are great fun to watch. There are two species in our stream, the shortfin (the smaller more common one) and the longfin which is classified as “at risk – declining”.  
It is of concern that we see signs of fishing and killing of eels in the gully. We cannot stress enough how enjoyable it is to feed them and enjoy seeing them. Killing them is pointless destruction particularly when most people would not be able to tell the difference between the longfin (classified as “at risk – declining”) and the more common shortfin eel.

Feeding the eels can be very rewarding

This link takes you to some interesting information about eels on the Stuff website:

Bird poo children’s project

Select a bird poo with seeds in it

Here is a project that children can do over the school holidays. Send them down to a wilderness area and see if they can find a bird poo that is full of seeds. Collect it up then sow it in a seed container and see what grows.
This demonstrates how useful birds are in distributing seeds.  Many of our native trees and shrubs have evolved to rely on our native birds to distribute their seeds.  The tawa, miro, pigeonwood and nikau, all of which have particularly large seeds, rely on our native pigeon - kereru – for their distribution.
Some introduced birds also help. The fruiting spikes of the kawakawa are prized by blackbirds.

Then sow them in a pottle
Unfortunately not all seed distribution is good. Birds do not distinguish between weed seeds that may be invasive or seeds of plants that may be alright, or even desirable, in your domestic garden but are not wanted in native bush areas. We have seedlings of bay trees, cherry trees and exotic palms just to name a few, germinating throughout the gully.

Prickly stick insect Acanthoxyla prasina

Stick insects are really hard to see in their natural habitat because of their incredible camouflage.  The one in this photo was found walking up the leg of the person who photograph it after walking through heavy foliage in the gully. This is only the second one seen by the restoration team that work in the gully each Wednesday. Eradicating rats and possums must help support the increase of natives such as these.
Some interesting facts from the Wanganui Chronicle submitted by Dr Mike Dickison who is the Curator of Natural History at Whanganui Regional Museum.
Stick insects are easy to keep. They only need a regular supply of green leaves and an occasional spray with a water mister. They're happy to be handled, and are a great "gateway insect" for children who might be nervous about handling a creepy-crawly, as they're completely harmless. They spend most of their time slowly munching on leaves and laying eggs. It's possible to breed stick insects even if you only have one as the prickly stick insect (Acanthoxyla), are parthenogenetic. This means that no males are needed, with mothers laying eggs from which hatch only daughters. In fact, until recently, no males had ever been seen. The one that was found, was in England of all places. The species had been introduced to England in the 1920s and is doing well. Males seem to be very rare mutants, not required for reproduction.
Unfortunately, stick insects have a short life expectancy. They hatch in spring, reach full size in a few months, and usually don't survive the winter.

Tui nest

We have had discussion previously on this blog about what tui nests look like. This has come about because of the increased number of tui present in the gully and sighting of immature birds in late summer. The example in this photo was found on a track in the Lake Rotoiti area after a storm. The small bits of egg shell in the nest would suggest that the chicks had hatched and probably left the nest prior to the nest being blown out of the tree.
Interestingly the number of tui sightings in the gully this winter seems far greater than any other year both in individuals flying about and numbers congregating in trees. Eleven tui were counted at one time in one tree and eighteen in another.

Tree Croppers car boot sale day

 The first Saturday of July each year the Tree Croppers Ass. run a car boot sale in one of the car parks in Hamilton Gardens. Mangaiti Gully Restoration Trust has sold trees there for a number of years as a fund raiser. This year’s was exceptionally good netting $660. Kawakawa were particularly popular this year.

Monday, June 4, 2018

Expanding the rat eradication programme

Due to popular demand we were approached to install bait stations in the Wairere section of the gully. This has been done over this winter. To make management a bit easier, and to allow for the varying floral types, we have divided Mangaiti Gully into three stages (sections). Mangaiti which runs from Sexton road to Gordonton Road. Wairere, a short gully section from the Hukanui Road entrance up to Wairere Drive (see map) and the Hukanui section which is everything in between these two.
We have acquired the services of two volunteers who are interested in servicing the bait stations one day every fortnight in the Mangaiti section and logging the service data in TrapNZ . This will greatly decrease the times between servicing the stations with the aim of suppressing the usual summer popular explosion of rats. 

Our Kauri Trees in the gully

 Kauri are not a species that are generally considered to have historically grown in Hamilton gullies. We therefore do not include kauri on our planting lists. However we do have several that have been planted some time prior to our Trust being involved with restoring the gully. Four of these are located at the top of the gully along Sexton Track. In 2014 when we were clearing the weeds in preparation for planting we discovered these four kauri covered and weighed down by vine. Four years later and look at them now. Four handsome specimens that actually have cones on!
With kauri die back devastating the northern kauri it may be time to rethink the policy of where we plant kauri. It’s been suggested to council that the southern gully slope below Sovereign Isles, that Wildlands have been contracted to clear and plant, be considered for a kauri grove of 40 to 50 trees. This site has several advantages; It will have a good vista from the existing board walk that runs from Hukanui road, it is a well-drained site that suits kauri, it is isolated from foot traffic therefore would have a very low possibility of contracting the disease at some future date (the disease is spread through soil movement) and being on the south side of Sovereign Isles they would not shade the houses at the top of the gully. There was a very positive response from council to this idea with a suggested planting date of 2020.

Willows on the way out

You may recall that we have been running a programme to poison all the willows. This programme was brought forward because of the willow aphid arriving from Australia causing a black sooty mould on all the understorey plants. All the poisoning is now complete. We then applied for and were successful in securing funding from the HCC community funding round to employ an arborist to remove all the willows that were at risk of falling across the tracks. This work has been started and will be continuing for a few more Wednesdays. The track network is being closed to the public on Wednesday mornings while this work is being done.

The willows that will not fall over tracks are being left to fall on their own and naturally rot down.
If there is not enough funding to complete the job this year we will apply for more funding to complete the job next year. 
Our worry now is, with all the sunlight coming in, the spring / summer weeds will be hard to control until the new canopy trees grow enough to shade them out.

A successful breeding year for Yellow Admiral butterflies

 Twenty Yellow Admiral butterflies hatched out of their chrysalis this autumn. A pleasing result for the first year. The butterfly nettle was grown in an urban garden. The netting was to protect them from the paper wasps that continually stalk the caterpillars. 
Our objective is to get the red admirals to breed. The reds are a lot rarer in our district although they have been seen.

Weed and goldfish released into pond

It very much looks as if a person who wanted to get rid of their gold fish emptied their aquarium, weed and all, into the pond in the gully. As a result this very invasive water weed multiplied to cover the pond within six months. It has been washed out the overflow into the stream and is now spreading downstream to the Waikato River. Gold fish themselves are a pest carp in the wild. We appreciate that the person who did this did it through ignorance not knowing what the ramifications are. However it is a good demonstration of the harm that can be done by transferring and releasing both fauna (animals) and flora (plants) into the wild of species that can be invasive.
It would only take one person to release a live rainbow skink (Australian pest skink) that their cat bought in, into our skink enclosure for it to be overrun by this invasive species. The rainbow is in parts of the city and might even be as close as Thomas Road.

What twenty years achieve in restoration

All too often we hear that “restoration takes so long to see a result” well this photo shows what plantings look like after a twenty year period. In the scheme of things twenty years is not really that long (I can imagine all the older folk adding twenty years onto their age. Yes, I do that too) but add it onto your children’s or grandchildren’s age and that make the effort well worthwhile. What a thing to leave for their generation to enjoy.
The other thing of course is that these trees are nowhere near their maturity.
You will note the swamp maire on the left side of the pond with its trunk in the water with bronze foliage. The totara has its head poking through the canopy at the back (dark green) and a rimu in front of it.
The person standing on the right gives it scale.

Citizen Science

On the 9th of April there was a citizen science symposium held at Te Papa Wellington. You may have heard the term but do you know what citizen science is all about?
Firstly the objective should have a meaningful scientific outcome. The ideal would be to have a paper published on the outcome so that the information collected could be shared.
The ideal citizen science project would have three participants;
An enabler. This person is usually attached to an organisation such as a city council or a government department such the department of conservation. They would coordinate the project and solicit funding.
The scientist. They would either develop, or review, the methodology to be used to ensure meaningful objectives were going to be met. Hopefully they would also write up and present a paper at its conclusion.
The community (group / volunteers). They would be the ones on the ground doing the collecting of data.

When designing the methodology there are two things to keep in mind.
The more people involved in collecting the data (the community group / volunteers) the simpler the methodology should be and it should require only minimal training.
If the collection of data is, by necessity complex, then it should only involve a very limited number of people who can be selected for suitability and training. 

This link is to a YouTube clip of Siobhan Leachman’s presentation at the symposium entitled “Developing a crowdsourcing project – Keeping volunteers on board (7:40).

Cartoon of the frog and climate change.

The boiling frog is a parable describing a frog being slowly boiled alive. The premise is that if a frog is put suddenly into boiling water, it will jump out, but if the frog is put in tepid water which is then brought to a boil slowly, it will not perceive the danger and will be cooked to death. The inference being that we are all being gradually brought to the boil with climate change.

Wednesday, February 14, 2018

2017 was a big year for Mangaiti Gully Restoration Trust

A summary of the major work done in 2017 has been documented below. All the labour for these projects was done by our regular volunteers without which these projects would not have happened.

Funding support was for materials only which our Trust was very grateful to receive.

In 2017 over 2000 plants were put into the ground

This was a big season for our Trust. The usual number of plants to go in each year tends to average around 1000. The Eastern Track area was the target planting area for 2017 and was completed. The reason for the higher number was that we had prepared Michaels area in the south expecting to plant in 2018 but due to Hamilton City Council having a planting allocation for Mangaiti Park that was not ready for planting, the plants were diverted to our prepared area. This worked in very well even though it put a bit of pressure on the volunteers.

For the second year we had Rototuna Primary School doing a planting of over 100 plants.

In 2017 we had great success in Rat eradication

North east suburb of Hamilton. Gordonton Road is the right hand boundary. 

One of the highlights of 2017 is the clearance of rats from a 20 hectare section of a 30 hectare gully system. To understand the significance of this you need to understand that half of that gully has no tracks, is extremely boggy and the only access is via the residential properties that border the gully (and that it was full of rats). It has been the support of the community that enabled this to happen. Sixty bait stations using bromadiolone (Contra) bait blocks (only a fifth the strength of brodifacoum) serviced by 16 community service agents that have been trained in Health and safety to handle the baits, service the station and record the results. A young tui was spotted in this area for the first time this season and an increase in weta numbers has been observed which, in all, indicates a recovery in the native biodiversity. A very successful urban programme achieved at a cost of less than $1000.

What is disappointing is the lack of interest and financial support for this project from the Hamilton institutions that supposedly are guardians of our environment.

In 2017 hundreds of Willows were drilled and poisoned

The giant willow aphid blew across from Australia and moved into the Waikato a couple of years ago putting pressure on us to get rid of the willows in the gully. The Aphis produce a dew that lands on the understorey plants creating a black sooty mould. This damages the understorey plants by reducing their ability to photosynthesise. It was always our intention to remove the willows but the aphids cause it to be moved up our “do list”. One of our volunteers purchased a good grunty drill for the job and has poisoned hundreds in the northern area of the gully. The last few that were missed are being poisoned at the moment to finish the job off.

In 2017 we built 266 metres of Tracks and board walks

 Part of our management plan is that, as we clear an area for planting, we put in tracks or board walks so that our volunteers have easy access to plant and maintain the areas. If the ground is firm enough we build tracks. If it is muddy then we go for board walks. Board walks are twice the price of tracks to build so a track is always our first option.  In 2017 two tracks and board walks were completed. One is the eastern (east side of the stream) ring track which is 186 metres long and the other going south below the pond is what we call Michaels track and is 80 metres.
Our trust had funding support of $2,800 from the Hamilton City Council Community Funding pool and $500 from Trust Waikato. The balance of $344 came out of Mangaiti’s Trust general funds account.