Sunday, December 10, 2017

Quote of the day

Lynda Hallinan, Sunday Star*Times, Nov 12, 2017

About possums being a pest in her garden;

“I’m am sure George Orwell’s dictatorial porkers would agree that while all animals are equal, some are more equally deserving of a bullet.”

Making tracking tunnels

The rat eradication programme is getting far better results than expected this early on. It is now important that we get the tracking tunnels out into the field to get accurate data on the rat population. We were fortunate to be donated old corr-flute election signs. These have been cut into tracking tunnels. The tunnels will be installed in the field over the next few weeks so that monitoring can start early in the New Year.

Grey warblers and shining cuckoos

With the pest eradication going on, one of the first bird species to increase will be the grey warbler. These little birds are often heard Grey warbler song (MP3, 527K)  but difficult to see. They busy themselves fossicking around in the undergrowth looking for invertebrates to feed on.  They have at least two broods a season. The second brood can be targeted by the migrating shining cuckoo that lay their eggs in the warbler nest. These cuckoos are very rarely seen because of their green plumage that blend into their surroundings. If you happen to be observing a warbler by its nest while a cuckoo is calling the warbler can get quite agitated. They obviously understand the threat.
Photo of nest from: Grey Warbler song DOC,

Grey gergone is the warbler

A tui nest

With the increase in tui activity in Mangaiti gully we have been frequently asked what a tui nest looks like. A Trust member was staying at a holiday home at Opoutere on the Coromandel and found G. J. H. Moon’s book Refocus on New Zealand Birds published in 1967 with some excellent photos and notes on his personal observations of bird activity around the nest while observing from his hide. I have reproduced the tui photo that shows the nest structure and summarised his notes to help you to identify a possible tui nesting site in your area.

From Moon’s notes:
·         The male is slightly larger than the female
·         Their diets consists of a wide variety of insects, small berries and nectar
·         Being nectar feeders they are ecologically important in transferring pollen from one flower to another
·         The nesting season normally extends from November to January but he has found nests in October.
·         In his district (Warkworth, North Auckland) the favourite nesting sites were in the outer branches of Totara and in the upper canopy of tall manuka but some nests are built in kahikatea, kowhai, and macrocarpa, from 10 feet (3 metres) to 50 feet (15 metres) above the ground. 
·         The nests are up to 10 inches (24cm) in diameter and built as per the photos. Two to four eggs form the usual clutch; these are pale pink or white, with brownish specks at the broader end. Incubation takes 14 days.

Trees for wood pigeons

Get your Forest and Bird calendar for 2018
 from your local book shop.
We are planning a very long term programme of planting canopy trees that attract our native wood pigeon back into Hamilton Gullies.  Some say there is food that they eat already in Hamilton but this is only bread and butter for them. We want to offer them ice cream and jelly. Their ice cream and jelly is the fruit of nikau, tawa, miro and pigeon wood. We will be targeting the whole 30 hectare Mangaiti gully system. Area size matters when planning something like this.
These trees do have some challenges though. Nikau is easy to grow from seed but is very slow growing. Tawa and pigeon wood are easy to grow from seed but frost tender when young so shelter is necessary. Miro is very hard to grow from seed but is frost hard and grows at a reasonable rate for a canopy tree. For miro collecting seedlings from under a tree where a pigeon roosts is the best bet. We have 40 plants on hand at varying sizes up to about a metre.
All four tree varieties will not tolerate wet feet so will have to be planted on the lower gully slopes.

Rototuna Primary School Planting day

A hundred odd school pupils from Rototuna Primary gave us a hand to plant an area of the gully again this spring. The student thoroughly enjoy the activity. This was supported by Hamilton City Council by supplying the plants. Back in the class room the students wrote and decorated lots of thankyou cards. The school have their own area within the school that they are planting.This year the school was rewarded for their efforts by being winning the NZ School of the Year for plant conservation. Well done Rototuna Primary. 

Book review

The History of Life in New Zealand
Fully revised Edition (2016)
By George Gibbs
Published by Potton & Burton

ISBN978 0 947503 08 6

Have you ever wondered why New Zealand’s plants and animals are so different from those in other countries? GHOSTS OF GONDWANA is the remarkable story of how and why life evolved in New Zealand.
The first thing you have to get your head around when reading GHOSTS OF GONDWANA, is the 85 million year time span within which the discussions take place. When you consider that Homo sapiens have been wandering the earth for just 500,000 years, it brings it into perspective.
The 85 million years ago as a starting point, is when Zealandia started moving away from Australia with the breaking up of Gondwana land. The formation of Zealandia as an independent land mass (being at times no more than a group of relatively small islands) and the evolutionary development of our flora and fauna over that time period, consisted of continual change in land forms caused by the rise and fall of sea level and  land movement from tectonic plate activity. This had a direct bearing on the evolution of our ecosystem as we know it today.
The book explains the difference between endemic (organisms that are restricted to one place and not found elsewhere) and indigenous or native (a species that is shared with another place). The line between the two is not always clear and at times requires molecular analysis (molecular phylogenetics) to resolve.
GHOSTS OF GONDWANA surveys the research of thirty case histories (birds, insects and plants) in its attempt to explain the what, where, when and how of each case.  No two cases are the same. There tends to be a considerable amount of theory and assumption within these case studies despite the recent use of molecular phylogenetics to answer many questions. The time frame is vast, evolution is slow and there is not always a trail of fossils left for our convenience.

The book is very well presented and is written in a very readable format. The subject is thoroughly interesting, but this is a specialist’s book so may well have limited appeal. It is however, highly recommended to anyone who has a deep interest in New Zealand’s natural history.

Tuesday, August 29, 2017

Longfin Eel. Enjoy them. Don’t destroy them

We have Longfin Eel in our Mangaiti Stream. This photo is of one up the headwaters at the Gordonton Road end that the local children regularly feed.
Longfin Eels are in the "at risk - declining" threatened status. They are the larger of our two eels. The other being the smaller and more common Shortfin Eel. The Longfin has a very interesting life cycle. They are endemic to New Zealand and grow in our rivers, streams and fresh water lakes to a good old age (can be 80 years). They are probably the biggest eel in the world. Slow growing and sometimes some females can reach 2 metres long and weigh up to 40kg.
On reaching their breeding size, the eels migrate to the sea. The details of the lifecycle are not clear. They swim for up to five or six months to tropical Pacific waters, possibly near Tonga, where they spawn and die. The eggs hatch into leaf-shaped larvae that float back to New Zealand on ocean currents.
Arriving in astounding numbers in spring, the larvae transform into slender, transparent “glass” eels. The glass eels soon turn into grey-brown elvers (young eels) and begin migrating upstream. And so the cycle repeats.

Mangaiti Gully Management plan

This management plan has been compiled by Mangaiti Gully Restoration Trust (MGRT) and covers the whole 30 hectares of gully. Its aim is to get everyone onto the same page; MGRT, gully neighbours, HCC, WRC and anyone else that may have an input into restoring Mangaiti Gully’s native biodiversity.
It covers flora (plants) and fauna (animals) management, threats and suggested ways of managing them, along with building infrastructure, education and social benefits among other things. If anyone would like a copy you are welcome to email your request to
(Unfortunately we are unable to attached a pdf file to this blog site)

Rat eradication programme

This has gained good momentum with 60 bait stations installed which are being serviced by 15 enthusiastic community service agents. These are the people that live on the gully edge and have been trained to service the bait stations and record that information into the TrapNZ website.
After six years since it conception this is a really interesting time for this project. On our page of TrapNZ all the information we require is being recorded to monitor the success or otherwise of the programme. After going through the next seasonal rat breeding cycle we will know by June / July next year whether we are going to achieve our objective of clearing out all breeding resident rats.
Click on the map to enlarge

A measure of the Fauna’s health

The health of the native fauna in any restoration project is the final piece of the jigsaw.  We really need to be able to measure how things are going. In the bush this is usually done by doing regular bird counts. However we run into difficulty in an urban situation where birds (Tui) can fly from one gully system to another with relative ease. To overcome this the Trust is developing a way of measuring the Tree Weta not just by the numbers present but by the size (length and weight). The Weta is predated on by both rats and possums (as well as Morepork) so we feel this would be a good indicator species for measuring fauna health. We have started to put up specially designed Weta homes for the project with the aim of having twenty or more spread throughout the gully system.

A book review

The Unburnt Egg
More stories of a museum curator

By Brian Gill
ISBN 978-1-927249-29-1
This first edition was published in 2016 by Awa Press

Brian Gill was curator of birds and other land vertebrates at Auckland War Memorial Museum for over thirty years. In his book “The unburnt Egg” he brings a dusty museum’s storeroom, its scientists and its creatures within the museum’s collection back to life in a most entertaining and informative way. Each chapter leads you off on another adventure around New Zealand or the Pacific; each story another chapter.
Even though it is a book of short stories, it is written in such a way that after completing a chapter you are eager to progress to the next, much like a good novel.
I thoroughly enjoyed reading this book and highly recommend it to anyone that has an interest in natural history.

Saturday, May 27, 2017

Lacebarks do the trick

Silk cover over the Puriri Moth Caterpillar hole
Mangaiti Gully Restoration Trust is an innovative, progressive Trust that is pushing conventional boundaries in urban restoration.  This means enhancing the environment within the gully system to take the negative pressure off the native fauna (birds, invertebrates, reptiles and fish) which urbanisation invariable brings.

Selective and targeted planting is one way to achieve this. An example is the Puriri Moth. An impressive native moth that is the largest native in NZ with a wing span of 150mm. Their caterpillar bore into the trunks of Grey Willow and Privet when native species are absent. If these are removed during weed clearing our native moth is also removed. To manage this, extensive planting of a native substitutes like Lace Bark is being done. This winter 62 Lace barks that we grew from seed have been planted in the latest cleared area. These grow relatively fast giving good early canopy cover which helps to shade out sun loving weeds.

Adult Puriri Moth

Red and Yellow Admiral Butterflies

Red Admiral
Progress is being made to reintroduce Red Admiral butter flies to the gully. We have propagated a number the nettle plants that they require for breeding. We are fencing off an out-of-the way area for the nettle and there will be signage on the fence to warning people that touching the plants will cause an unpleasant irritation.

Yellow Admiral
We have identified a river bank on the Hauraki plans that has nettle and Red Admirable butterflies. This will be the source of stock once our nettle plants are established. Yellow admirals are already present in the gully so we are looking forward for their population to increase.

New track being constructed

One of the things Paul Duffy from Hamilton City Council (now works for Auckland Council) said when we first started this project was, "don’t have the tracks going in a straight line. It is much more interesting to meander through the bush". We have started to push through another track into a new planting area and with Paul advice put curves in it. It does look impressive.

Working with continual threats

Rainbow Skink
There always seems to be some threat to our restoration programme in an urban location. There is the perennial rat and possum invasion to control. Now we have Rainbow skinks, an invasive species from Australia that is common in some areas of Hamilton and is being easily spread. One of our team members purchased to load of firewood and found one among the wood. The Rainbows are prolific breeders out breeding our native Copper Skinks.   

Giant Willow Apids
Then there is the Giant Willow aphid which arrived a couple of years ago, which in its self does not attack our native trees but in our gully produce so much honey dew that the understory of natives got covered in black mould  cutting off, or heavily restricting, the understory plants ability to photosynthesise. We are poisoning the willows but that is a big job that we cannot do all at once. 

 Myrtle Rust

Now it looks as though we will have to contend with Myrtle Rust in the near future.

Book review

The Song of the Dodo Island Biogeography in an Age of Extinction
By David Quammen
A Scribner 1996 publication
This brilliant, easy to read book is about the unravelling ecosystems, ecosystem decay and about evolution and extinction. David Quammen travels the earth visiting islands and reserves where science is being done on the environmental pressures, predominantly from humans, that is driving many species into extinction. While the ecosystem decay does dominate this book, running parallel is his investigation and documentation of how species evolved in the first place, with the main focus on the animal evolution on isolated islands – island biogeography. There is interesting discussion on the Wallace line that divides Indonesia into two separate evolutionary segments with Asian fauna on one side and the Australian fauna on the other.  He follows Alfred Wallace’s adventures that led to this discovery in 1859 and the lead up to Darwin’s publication of the Origin of Species. 
While the subject could be pretty heavy going to read, Quammen has scripted it is such a way that it flows well into a “hard to put down” book. All 625 pages of it. This book is brilliant. It’s so good it is the only book I have ever started to read a second time and still enormously enjoy reading. 
David Quammen is a two-time National Magazine Award winner for his science essays and other work in Outside magazine. The author of three novels and several other books, he is the recipient of an Academy award in literature from the American Academy of Arts and Letters. 

Plant barrow

The advantage of being part of a team is that you get a variety of talents. The standard wheel barrow is not really that suitable for carting plants around so one of team members built a platform on a wheel barrow base specially designed to carry pants. It works a treat and carries three time more than a standard barrow.

Saturday, February 18, 2017

Broken bridge

The broken bridge
One of the down sides to opening up an area to the public is that it also opens it up to vandalism. Overall we get off pretty lightly with things that are easy and cheap to repair. This was not the case with the latest damage to one of our bridges. A number of people jumping on the bridge managed to break it in half. We rebuilt the bridge to a more sturdy but costly design. This replacement cost the Trust $205 for materials, money which would have been used for plants or pest control.
All rebuilt and solid. 
An opportunity to donate

If you feel inclined to contribute towards the cost of the bridge rebuild you would be welcome to make a deposit (any amount would be welcome) as a direct credit into our bank account 031557-0463402-00. We are a registered charity so if you email our Treasurer  confirming your donation details we will supply you with a receipt for your tax rebate.

New Area being cleared

Cabbage Tree Seedlings before clearing
There is quite an extensive area south of the pond and east of the stream on the wet gully floor that a house owner who lived on the gully had cleared of willows and done some sparse planting. They sold their house and moved from the area about two years ago. This area has since been overrun with the swamp grass Glyceria maxima putting considerable pressure on the existing plantings of natives. We decided to put together a rescue package that would control the Glyceria and return the area to native flora suitable for the swamp conditions.
Glyceria thrives in wet sunny conditions. We have found that by thick planting Manuka at one metre spacing we can shade out the Glyceria. It becomes very weak in the shade. We then under plant the Manuka with shade tolerant natives which will eventually grow up through the Manuka restoring the area to a good native wetland mix.

and after clearing
We are at the stage where we have cut down the Glyceria, freeing the existing native plants, some of which were bent in two, and will bring the Glyceria under temporary control by spraying with glyphosate (you may know it as Round Up). This looks as though it kills it but does not have a permanent kill and soon comes away again. The next challenge will be to get enough Manuka plants for the area. In reality we will probably have to do in it blocks over a number of seasons.

Hosting Chartwell Cub Pack

Building bridges
On Tuesday 6 December from 6:30pm to 8:00pm (actually went later) Mangaiti Gully hosted about 30 cubs from the Chartwell Pack. This was broken down to six teams of five to six Cubs who are aged between 7 to 11 years. One of our Gully members drew up an orientating type activity where each team had set tasks. Things like identifying native plants from a photo and collecting a leaf, potting up seedling cabbage trees to take home, feeding eels in the stream all while finding their way round the tracks in the gully from a map supplied.
These activities ceased at 6.45pm and they all met on a stream edge flat for each team to build a bridge from poles supplied followed by building a small fire each in pre-built brick fireplaces.
The evening ended with drinks of Milo and toasted marshmallows over the fire.

Roasting marsh mellows for supper
There was one adult with each group at all times plus heaps of other adults - probably two Cubs to one adult by the time the Gully people and parents were counted. It was a really fun evening with the adults enjoying themselves as much as the Cubs. What was really great was that this group could experience these “wilderness” activities right here in the city. 

Millipedes Diplopoda

  While on our knees weeding out wild strawberries growing on the gully flat it was noticed how abundant this little Millipede was. Looking up this little critter in my books when I got home I found out there are about 600 species in New Zealand ranging in size from 20 to 100mm. The NZ species have separate sexes and the pale yellow-brown eggs are laid in special cavities lined with or made entirely from soil. Now here is the interestingly weird thing; the eggs hatch into young with three segments. A pair of legs on each side (millipedes have two legs on each side of their segment. Centipedes have only one). More body segments and legs are added at each moult. Millipedes are entirely vegetarian feeding mostly on decaying plant matter whereas Centipedes are carnivorous feeding on insect and spiders.
These were all within the flood plain of the gully floor so we’re wondering what happened to them when the creek flooded its banks which happens reasonably frequently.

Praying mantises eating a Monarch caterpillar

It is that season again when many of us have swan plants growing and have the pleasure of witnessing the life cycle of the Monarch Butterflies. This gives ongoing interest to both young and old. It also brings home the reality that an insect’s life is a brutal fight for survival. Most know that the paper wasp attacks the caterpillar stage of the Monarchs particularly when they are small but have any of you witnessed a Praying Mantises devouring a large caterpillar? Not a pretty sight.

Weta from the wood pile

An interesting little snippet. This handsome specimen of a Weta was found in a wood pile at a home.  It was taken down to the gully and released.