Friday, 18 October 2013

Ringing Wrybills


The Wrybill lives exclusively in New Zealand. It has a uniquely shaped bill that bends at the tip to the right.

Wrybill Anarhynchus frontalis: in typical braided river breeding habitat.
Viewed from the side the bird appears to have an unusually long bill for a plover. 

From the side the bill appears long and straight.
The bill is straight for most of its length, up to what could be considered within the normal range for the size of the bird, but then it appears to have a curved implement stuck on the end making it longer. The bend is between the range of about 12° and 25°.

From above the curve can be seen and appears,like an extension to a normal bill.
In the southern summer months it breeds in the braided river beds of the South Island where recently it has become vulnerable to disturbance by the increased use of 4x4s and quad bikes, indeed there is apparently a 4x4 outlet that uses these rivers to demonstarte its vehicles adding pressure to an already vulnerable environment.

Wrybill in typical braided river habitat.
In the winter the birds move to the North Island and can be found around the northern end on estauries and beaches. Some birds, presumably first year birds, remain for their first summer on the North Island.

Wrybills on the Manawatu estuary on North Island.
The interesting thing is that when they feed, even when there are no pebbles under which to search, they still put their head to one side to catch prey.

Wrybill circumnavigating an imaginary pebble.

We had the immense good fortune to be able to join John Dowding and Antje Leseberg on the River Rakaia close to where the plains meet the Southern Alps that are being pushed ever skywards by the clashing of two great tectonic plates.

Antje Leseberg and John Dowding.

The weather was good which meant that ringing nesting birds was not going to prejudice the chances of the nest by the eggs being chilled by rain.

Rakaia River: A typical 'modern' braided river habitat. I say 'modern' because
much of the vegetation is actually introduced these days but the classic
twisting streams within the stoney river bed is timeless.
As we set off across the braided river bed, having crossed the first of the icy streams which, upon entering seem to sever your feet from the ends of your legs with the shocking temperature of the water, we were suddenly rushed by a female Wrybill. She ran straight at us and then tried to lure us away from our intended path. This was a sure sign that she had a nest, so we all backed off sufficiently for her to settle down and return to the nest. Once that was pinpointed John approached the nest with a much practiced eye, not allowing the birds activity to deflect his attention. In the nest we found two pale rock-coloured eggs.
 
John pointing to the two incredibly well camouflaged eggs.
The next stage was to establish a temporary ringing station and John prepared all his gear, in the meantime the bird returned to its nest. I was a little alarmed to see a syringe with a needle attached among his implements, but was reassured when I discovered it contained nothing more sinister than glue to bond the coloured, plastic leg rings. Everything prepared, all that was required now was to catch the bird. John produced an oblong grid with multiple nooses attached made form fishing line. Known for obvious reasons as a noose mat, this contraption was the easiest method of catching the birds. 

The simple but effective noose mat.
The bird's habit of rushing towards you when you approach the nest could be put to good use here. Placing the mat between him and the bird John positioned himself such that as the bird approached him it would cross the mat and become ensnared in one of the nooses. 

Wrybill approaching the noose mat.
I am convinced this is much harder than it sounds or indeed looked, but John soon had the bird in the hand and then resting apparently peacefully on a cloth on his lap (I’m sure the bird didn’t see it that way, it probably felt like I do when I am apparently relaxed in a dentist's chair). The bird was then ringed and I was delighted when John asked if I would like to release the bird. Before coming to New Zealand I had hoped to merely see this enigmatic bird, maybe we'd even get good views and photographs, but I never dreamed I’d get the opportunity to get this close.
 
I recognise those podgy little hands!
John and Antje then headed out across the river bed, fording streams that Elis and I could not, or more precisely, would not cross.

Trust me, that water was a glacier not long ago and is very cold indeed.

They rung two more birds while Elis and I enjoyed watching and photographing other birds of the braided river habitat; Double-banded Plovers, Black-fronted Terns, Paradise Shelduck and South Island Pied Oystercatcher (SIPO).
 
Double-banded Plover Charadrius bicinctus; pleasingly common along the braided rivers.
We then moved further up the river, closer still to the mountain and there was rain deep in the sharply hewn valley to our left.

There's rain in them tere hills!
On the way we disturbed a SIPO pair from their nest and found two eggs in the simple scrape. 

South Island Pied Oystercatcher Haematopus finschi: pair defending their nest.
South Island Pied Oystercatcher eggs.

We then located a rung another female Wrybill.

John's mobile one man ringing station.
This time Elis got to release before the rain began to approach from its cradle in the mountains spreading across the broad flat valley, for the welfare of the birds and eggs further ringing was not going to be possible, so we packed up and left.

Elis releasing a Wrybill.
That evening we greatly enjoyed the company of John and his delightful Australian wife Elaine and it turns out that John is not just an accomplished conservationist and biologist, he is also a fine cook, serving up a delicious lamb and chickpea stew. John also supplied us with much information for the rest of our trip as to where to find which waders, his help and advice were invaluable to us.

John and Elaine Dowding

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