Braided Riverbeds

Update on inland Otago bio diversity

kea; aspiring; hut

Tena koutou katoa

I’ve had it in mind for a wee while to do a sort of good news newsletter, so here it is.

The new year of 2012 has progressed into feelings of autumn in the air. Things were pretty hectic for me at the end of last year. Family and close friends stuff – mostly health issues (now resolved) and a couple of deaths.

So here is my news garnered from a few sources – people at the coal face doing the work. Two of which are retired DOC people. With a lifetime of experience in many responsible roles:

Ten years ago 25 Sth Island robin were bought back into the West Matukituki Valley and released near Aspiring Hut. Now they total an estimated 300 and have spread up valley and down to into the Rob Roy valley and the East branch of the Matukituki.

The initial instigator of this was my good friend Stu. He and Heather are still tracking the birds and are now close to saying the project is closed.

Prior to 3 poison drops since 2014 and the subsequent installation of nearly a thousand traps by the Matukituki Trust in partnership with DOC, the survival rate has gone up from 1 fledgling out of 4 surviving to 4 out of 4, estimated.

The buff weka project – another relocation by Stu. At least 30 years ago he bought a bunch of birds back from the Chatham Islands and established an aviary on Stevenson Island on Lake Wanaka. So each hatching had the best chance of success. Then they were re-estabished on other islands in the immediate area around Wanaka and Queenstown.

One way or another I’ve taken an interest in this project too, after doing work on the island long ago. I will soon be mooting for getting some up-to-data data on numbers and well being. And likewise I’m taking quite an interest in braided river species/locals. Over a decade I’ve helped on many of the surveys. Based on what we’ve learnt I think how they are done needs a reexamination. Work in progress – best done before next spring!

One of the locals – tūturiwhatu / banded dotterel strutting his/her stuff

Another old friend Paul has gone from advancing the Matukituki Trust plans to coordinating several trusts and organisations trapping between Wanaka and the upper West Matukituki and lower East Matukituki.

Here is a now out-of-date map showing the gaps to filled up the valley. Glendhu Bay being on the left. Last I heard over 1600 traps.

The Matukituki Trust has just installed a new trap line up to the top of Cascade Saddle at 1800 mts

And another up an old track to the right here of Shovel Flat. Again up into the subalpine. The track being a rough line, up to Glengyle, put in by our old friend Geoff who ran Mountain Recreation climbing instruction courses for years out of Shovel Flat.

While looking at the above photo note that is French Ridge in the shade above the trampers. There is another line up there also, to away above the winter snow line. And in the valley to the right of the ridge we have Gloomy Gorge. Home of a rock wren population and bunch of stoats. So there is another line in there as well.
All this is in extremely steep and rugged terrain. A lot of the trappings is done with helicopter support. Groups being dropped off at the top, just like farmers now do mustering.

Also up to 14 have been hanging about French Ridge – probably the same birds. And other good news has been 27 spotted on Cascade Saddle by a ski touring friend. On the weekend before Labour weekend last year.
Not in our area, but also an unprecedented 13 of, are now frequenting the Red Tarns track at Mt Cook village

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Back in 2014 – 17 there were only two kaka in the valley. And then I found one dead near a trappinator [‘possum trap]. After much forensic work we decided both it and a stoat had taken an interest in a dead possum and the stoat pounced on the kaka.

Now it’s a similar story to the robins: there are several down valley and up the East Branch

On closing Wanaka/Matukituki news: other species are back in abundance, which means the dawn chorus is back – no more sleeping in at Aspiring Hut!

Also the potential hut rebuild decision-making with the Alpine Club and DOC is still fraught with tough calls. Geo technical in nature. Nothing will be a happening this season.

I’ve not mentioned the vast Makarora catchment. Good things are happening there also >>

And Forest and Bird, the old timers in the area, are still doing the work of unsung heroes. Trapping, trapping and trapping. Also trialing electronic means for traps to send info via satellite as to their status.

Ngā mihi
Donald

PS If you haven’t seen it already and have 4 minutes to kill then check out this attached link to the video taken by Crux on the Matukituki Charitable Trust a couple of weeks ago.

And on Radio NZ over the weekend – some very useful good thoughts during 27 mins. of:
Lonely Planet founder Tony Wheeler.

Braided River Bird Monitoring – how it works

Braided rivers are a common in Alaska, Canada, New Zealand’s South Island, and the Himalayas, which all contain young, rapidly eroding mountains. They are a unique environment inhabited by equally unique birds.

They simply cannot contain a river in a straight line. In floods especially they carry sediment, and in places where the flow slows down this settles on the bottom, thus raising it. And the water flows off to the side of least resistance. This will happen constantly during floods.

The technique for gathering bird numbers on these sort of rivers is quite simple: a team of four people spread out, in radio contact with each other, walk downstream counting every bird they see in front of them. On the ground or airborne.

And at that point the simplicity vanishes! Very finely tuned river crossing skills are needed, as well as “an eye” for the line that will give the best results. Plus physical stamina.

The tools of the trade are: a radio each, walking pole to aid crossings, binoculars, sun-cream, sun hat, good boots and gaiters [to stop gravels getting in the socks], GPS each, and a pen/paper/clipboard. Plus lunch, warm clothing, a camera etc. Warm dry socks also help at the end of the day.

A view upstream of the Hunter River that feeds Lake Hawea in Otago, New Zealand

Preparation. In this case to get into the very remote Hunter Valley. In the Wanaka area two other rivers, the Matukituki and Makarora are also done, and they don’t require a helicopter drop in. There is 25 years now of history – each river being monitored every third year.

The three year cycle is sometimes hard to maintain. The work has to be done in the spring when the birds are breeding, and this is when there is a high frequency of floods, with high levels due to snow melt.

After a short but steep climb in the helicopter from Makarora town-ship, on popping over the ridge the large and rugged Mckerrow Range come into full panoramic view [actually named after a close friend’s grandfather who did lots of surveying and exploring.

Dropping the over-night gear off by a hut, before flying further up the valley to begin the survey.

On the left [note the silt in the grass!] where we only go to avoid a complex river crossing; and where we do – the gravel on the right.

One species of many that we’re looking for. The ‎nationally vulnerable banded dotterel / tūturiwhatu, is the most common small plover of New Zealand seashores, estuaries and riverbeds.

This one is feigning a broken wing to lead the surveyor/photographer away from a nest.

After breeding, they either remain at the nesting area or move relatively short distances to nearby estuaries.

Typical nesting surface, and one of the team striding it out. Being very careful to not stand on eggs!

On the wing. A black fronted tern. Not in the Hunter though, but the Tasman River near Mt Cook. The blue colouring of the very cold water is caused by rock ground up by glaciers.

There are about six species that are primarily dependent on the braided river habitat: wrybill, banded dotterel, south island pied oyster-catcher, black-fronted tern, black-billed gull, black stilt) as well as the caspian tern and the pied stilt. The villain of the piece though is the black-back gull, as they predate on the eggs of the others.

Teaming up – linking arms for mutual support. Lots of concentration is required so it’s harder to observe what maybe in the air ahead. However the most experienced person leading the crossing, which is nearly done, has in this instance time to look. River crossing is best done by not looking down, which upsets balance, and with great care – there is no Plan B if people get swept away.

When not to cross at all – just too big and not braided into smaller channels.

What we don’t want to see, but if we do, weeds are recorded as Way Points on a GPS, so that DOC staff can return later to deal to them. The most often encountered on the above mentioned rivers is this area, is often broom.

We don’t encounter many lupins in the above mentioned rivers. This photo is in the nearby Ahuriri. Lupins, which the birds don’t like, offer cover to predators. Foolishly seeds were spread many decades ago by well meaning people wanting to add some colour to the grey landscape. And the seeds can remain for years until uncovered by a flood as they’re coated with a protective oil.

A sad aspect of some surveys is that we know that after a bank-to-bank spring flood hundreds of these young birds are washed away. These are a few surviving gulls after such an event in the Matukituki a few years back.

Knock off time – a classic old-time hut.

Evening and time for sleep. Tomorrow morning the survey will resume tidying up the riverbed to the right.

The long and sometimes bumpy drive home beside Lake Hawea

Obviously the results of such monitoring give a good guide as to the health of the environments concerned.

However the data as regards where breeding colonies are located, can be used for the most efficient locations for a new trapping lines. There is an attrition of traps though – during floods despite them being anchored by a chain to a long steel stake hammered in, they get washed away. Often the best compromise often considered, is for them to be near a bank that exhibits a history of stability, and place them with a shorter distance apart than the 200 mt standard in the bush, so as to create a fence of sorts.

The great New Zealand lupin debate and why it matters

First we need to talk about the lupin’s favoured environment being mainily the braided rivers which drain the Southern Alps – rivers that find it impossible to run in a straight line, and be anything other than dynamic.

When in flood braided rivers carry sediment from the ever rising mountains [geologically speaking] and landslides that frequent such a young country, and at every point where the water flow slows down the carried sediment settles onto the bed of the river, thus in time raising the level of same, and the river, seeking always the path of least resistance, flows off to the side. Thus during high water levels and floods the nature of this predominately gravel environment can change in several hours

The Hunter River that flows into Lake Hawea…

The delightful, endemic and endangered NZ banded dotterel / tuturiwhatu is one of many birds that has evolved to breed in these river beds. Despite exhibiting a variety of seasonal movement patterns ranging from sedentary behaviour, through migration within New Zealand, to trans-Tasman migration, it is hard to not love their comical stop-start actions…

This is typical tuturiwhatu breeding ground – also shared with wrybill and other like minded birds. OK to us humans it is pretty desolate, but keep in mind it lets them see any predators, and when they do they mimic an injury to lure rats, cats and stoats away from off-spring…

Well meaning flower lovers of decades ago decided to brighten up the desolation, and spread the non native lupin seed. They probably never realised the above, and that each seed being coated with a type of oil to preserve it, can survive for several years sprouting only when ideal conditions exist. The perfect seed for such a dynamic bed – they of course then become impossible to get rid of, apart from annual spraying and that is not a cunning or cheap thing to do in waterways annually…

And then there are wilding pines – these ones have been sprayed. The terrain hosting cushion type vegetation is again the sort chosen for nesting…

No one denies the lupins look beautiful. And by-the-way after the brief flowering is over they become anything but ethereal, and more of an eyesore…

Another beautiful frequenter of the braided river environment is the black fronted tern tarapirohe. They spend hours swooping for bugs above and on the glacial silt laden blue/grey water surface, and of course breed nearby…

The natural state as another dawn breaks on a braided river in The Southern Alps…

If only lupins could be confined to roadsides! But even in such a place they invite suicide by flowery eyed tourists, toting cameras that are scant protection against the 110km/hr traffic that rushes by their nearby vehicles, the parking of which is more spontaneous than well thought out…

The two villains together on the shores of Lake Pukaki…

The uniquely billed wrybill / ngutuparore which breeds only in braided rivers of the South Island. It is the only bird in the world with a laterally-curved bill [curved to the right], which it uses to reach insect larvae under rounded riverbed stones. Wrybills are completely dependent on the greywacke shingle of the riverbeds…

Category: Braided Riverbeds

Update on inland Otago bio diversity

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Braided River Bird Monitoring – how it works

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The great New Zealand lupin debate and why it matters

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