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
ISBN978-0-684-82712-4
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 pamackie@xtra.co.nz  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.