Robertson's weather - extraordinarily ordinary.

Well, we are not having the floods of Queensland, although our location on top of the escarpment is equivalent to that of Toowoomba.

What we are getting is grey, misty skies. Sometimes raining, sometimes leaking watery sunlight through the clouds.

It is difficult to make Robertson's weather sound "romantic". The best I can say is that in Robertson we do "ordinary" weather "extraordinarily well".

This month, our rainfall has been consistent, but not dramatic. Rain, alternating with mist, drizzle, more mist, rain and fog.The rainfall so far this month has been: 0; 2; 0; 4; 0; 0.5; 0; 15; 7; 24; 24; 43; 1 (all in mm).

Unlike the Inuit people of Greenland (who according to Peter Hoeg, in "Miss Smilla's feeling for snow" ) have more than twenty different words for snow, we Robertson people do not, but we can go close for different words for fog. 

Well, actually we could if we were a more literate society (instead of a Potato-growing, Rugby League-obsessed community).

I measure the fog by the visibility factor - how far I can see through the fog.

There is a standard measure. Aircraft pilots have defined fog and mist as follows:
"Fog is visibility less than 1000 meters and mist, by definition, is visibility between 1000 and 5000 meters. Both have their origins in light suspended cloud droplets with a nearly 100% relative humidity and an abundance of condensation nuclei."

Are they kidding? 

That's not a real fog - not in Robertson, anyway.

Visibility reduced to 5 Kms approx (beyond Belmore Falls)

 I measure Real Robertson Fog in terms of 

those trees which are the furthest away which I can see from my back deck.

• If the trees at the Cemetery (800 metres away) disappear, that is a light fog.
• if the Power stanchion in the next paddock below my house, disappears, that is a medium fog, or more likely, a heavy rain cloud rolling in from Kangaroo Valley.

Visibility reduced to my back paddock - 200 metres.

Bright light, medium fog

• If the trees in the lower paddock (100 metres away) disappear, that is a medium-thick fog.

Medium-thick Fog - today

•   There is another complication - the depth of fog directly above me. In other words, is the fog really part of a dense cloud? If so, it dramatically lessens the available light. So I can have a bright fog, a dull fog, or a dark fog, depending not on the "density" of the fog itself, but the amount of light coming through the clouds above. Sometimes the light in a fog can be so bright as to almost cause "white out". Yet it can still be a thick fog.

• Of course, there is yet another factor - I can have clear air (in my immediate vicinity)  but be looking at a wall of fog rolling up the valley. That is illustrated in the series of photos in the blog post from October 23, 2008.
• If the furthest tree I can see is the Sassafras growing 30 metres from my house, then, and only then, do I rate that as a true thick Robertson fog.

DRIVING IN FOG?  

I suggest you take note of the white road "dividing markers" kindly used on the main roads in the Robertson area by the RTA. Because we are an area known for experiencing fog, they are very strict in ensuring our roads are marked.

RTA illustration

• According to Table 4.1 in that document linked above, the white lines are 3 metres long, and spaced at 9 metre intervals.

• If you can (just) see the next white line mark, you have a fog visibility factor measured at 12 metres. Two white lines, means you can see out to 24 metres. Either way, that is a serious fog and it is a definite road hazard.

VISIBILITY APPROX 24 METRES - SLOW DOWN

• If you are driving in such a fog, my advice would be: 

1. Adjust your driving speed according to the conditions. 
2. Slow down, 
3. Put your head lights on (even in daylight). 
4. Experienced local drivers use their hazard lights (blinkers).

Yet another Beard Orchid - Calochilus gracillimus

On Sunday, in the wet, I went with Alan Stephenson, Colin and Mischa and Kirsten (same crew as detailed on yesterday's post), to see an uncommon species of Beard Orchid which grows in the area of sandstone forest behind Nowra. I was having trouble with my new Flash, so my photos are very poor quality. I will only show one of mine.

Calochilus gracillimus - Slender Beard Orchid

I have used two images kindly sent to me by Alan Stephenson.
This one is appropriately named "Slender Beard Orchid" (Calochilus gracillimus). (Note the slender stem in the background of the shot).

Calochilus gracillimus  (Photo Alan Stephenson)

Even better, it is also known as the "Late Beard Orchid" for it is only just flowering now, in mid-January.

Calochilus gracillimus  (Photo Alan Stephenson)

Many thanks to Alan for showing us where these plants were to be found, and for the photos.

As wet as Little Ducks

It seems to me that little Duck Orchids love to flower in the rain. The only times I have seen them, that has been the case. 2 out of 2 = 100%. I'll let you draw your own conclusions.

I first saw these Small Duck Orchids (Caleana minor, or Paracaleana minor, or  Sullivania minor) at Lithgow, on a very wet weekend which began what we now realise was the start of our wet summer season. Chris Jonkers kindly sent me photos of this Orchid, in late December (when there was a break in the wet weather).

Small Duck Orchid, Vincentia, 9 Jan 2011

 This weekend, with Colin and Mischa Rowan, Alan Stephenson and Kirsten - all members of Illawarra Branch of ANOS - I went to Vincentia - in the pouring rain. Where these plants are growing is on a small area of sandstone heath country and moss gardens, on an exposed rock shelf. After heavy rain the water was pouring off the hillside behind us, and so to photograph these Orchids required lying face down in the wet moss beds and trying to peer through a misted-up view finder. The same problems I had up in Lithgow all those weeks ago.

Small Duck Orchid - in the rain

Duck by name, Duck by nature. I reckon these flowers love the rain.
I know I don't, and my camera doesn't.

A "Squawk" of baby Currawongs

On Thursday morning in Robertson, it was damp and overcast. Normally a good thing for the birds I feed on my feed table - Bowerbirds and Lewin's Honeyeaters especially.

Suddenly, instead of hearing the low growls and metallic whirring noises of the Bowerbirds, I heard a cacophony of loud whistles, and the distinctive carolling calls of numerous Pied Currawong (Strepera graculina). So loud and so many calls I rushed to the back door to check it out. 


There were at least a dozen birds on the feeder table, on the roof gutter, in the trees around, and flying overhead. My brother counted 35 birds as the flock flew off.


They demolished the fruit on the feeder - apples and the remains of some watermelon.


These birds, when they form a pack like this, totally dominate all other birds, to such an extent that I reserve the right to chase Currawongs away. 

But there was something odd about this gathering. Most of the birds were juveniles. They black feathers were tinged with brown, especially on the neck and shoulders, and their gapes (corner of the beak) were still yellowish.

The flock which I am talking about

was of first season birds, mostly.

They were older than this baby Pied Currawong
- from 27 November 2010

but they were still all of the same season , not as brown as this one.

But they were but definitely not shiny black (and white) like true adults.

Fledgling Pied Currawong from 27 November 2010

But such a large gathering?


Normally I am used to seeing flocks of Currawongs in late autumn and winter. This was a cool morning, in the first week of January. High Summer.


What is going on?


To me it seems way too early in the season for such a large gathering of Currawongs.

*****

Juvenile Little Raven

Here is another juvenile bird, a rare visitor to my feeder table - a juvenile Little Raven (Corvus mellori). There is not very much "little" about a Little Raven unless you are comparing it to an Australian Raven. Compared to my regular visitors, Pied Currawongs and Bowerbirds, this is a big bird. It was travelling with two adult "Little Ravens".

*****

Comments welcomed as to whether such a gathering is unusually early?

Do Pied Currawongs form "creches".

*****

On a  totally different subject, what is the best collective noun for such a gathering? I have suggested a "Squawk" of Baby Currawongs.

Goanna roaming on Tallowa Dam road.

Down in the Kangaroo Valley last weekend, on the Tallowa Dam Road, we saw three Goannas within one kilometre. Two were large, almost scary I would have to say.

Goannas are technically known as Lace Monitors, or Varanus varius.

Goanna up a small tree.

The first was on the road, and it made its way straight up a tree. That is normal Goanna behaviour, as far as I know. At first it climbed about 4 metres high. Then it seemed to get a bit nervous as I was busy trying to get a good shot of it. So it climbed a bit further. I would estimate that it was nearly 2 metres long. 
It had a large prominent abdomen. I have no idea what it had in its stomach, but there is a prominent ridge visible in its stomach, so I can only guess that it had recently consumed something with a long tail - most likely a large snake. But that is a guess.

Look at the extended belly. Lunch might have been a snake.

Varanus varius head and front feet claws

Second Goanna - roaming actively.

We continued down the road and saw an even larger Goanna. I would say this one was over 2.5 metres head to tail. Look at the length of the neck and the size of the head - side on. It was roaming actively, just off the road, on a lower level than the road. 
Early in our encounter, it came close up, towards me, and believe me, I was nervous. Its tongue was flicking out, repeatedly "tasting the air".  Fortunately there was a broken shrub between the Goanna and me.

Tongue flicking is the way Goannas "sniff out their prey"

It then turned back and continued roaming actively on the rock shelf below the road edge. I am glad it decided not to keep coming towards me - knowing the size of the claws on the other Goanna.

 From the sublime to the ridiculous, we saw a small young Goanna on the road. Kirsten stopped ot prevent running over it, and it ran under her car, as another car approached - on this fairly busy road. It must then have scampered off, for we did not see it again. It had a small forked tongue, just like the adult I had just seen.


Three Goannas in one kilometre of road is pretty amazing.

Flagged Pied Oystercatcher traced

I am pleased to report that the Pied Oystercatcher I reported as seen on 28 December 2010 at Shoalhaven Heads ocean beach has been traced.

Flagged Pied Oystercatcher #35 Yellow, right tarsus

Today I received this email back from Clive Minton, from the Victorian Wader Study Group.


Dear Denis,

Many thanks indeed for reporting the Oyc with yellow flag 35. This is a bird banded at Barry Beach in Corner Inlet (near Wilson's Promentory) on 26th April 2008. It is yet another nice example of a bird in a Corner Inlet flock which had travelled up the New South Wales coast, often remaining there to breed.

There is some confusion from some people about the Oystercatcher colour-flag codes used in eastern Australia. Yellow is used by the Victorian Wader Study Group for birds flagged in Corner Inlet, the flag being on the right tibia. A yellow flag is also used on Oystercatcher chicks on the northern New South Wales coast by Greg Clancy, but his flags are all put on the left tibia. His engravings at the moment only range from A1 down to about K9 whereas a much wider spectrum is used. Populations do seem to overlap a little around Sydney!
Do please report any further sightings of colour-marked  Oystercatchers , including yellow 35 if it continues to remain in the same area for any length of time.

Many many thanks,

Clive Minton. 

*****

So, there we have it. Corner Inlet is 600 Kms south-west from Shoalhaven Heads. Add a bit more for following the coastline, precisely as an Oystercatcher would do.

Re the "confusion" over colour flag protocols, I was following the published "Protocol" codes for the Eastern Australian Flyway, as controlled by the Asian Pacific Shorebird Network.


With regard to the comment about likely breeding on the NSW coast, I can confirm this bird was happily "paired off" with another Pied Oystercatcher.

"Flagged" Pied Oystercatcher on right, with a mate.

I can also confirm that this bird did have a metal (numbered) band on the left leg - which was not visible in the other images.


This chance "sighting"of an identifiable bird (number on coloured Flag legible) came about because of a "beached" Whale. But there are many people walking along the NSW coast at present, so Clive and his colleagues elsewhere in Australia and overseas who "flag" waders are delighted to receive reports such as mine.


So, if anyone else sees this bird, or another "Flagged" wader, Clive Minton of the Victorian Wader Study Group can be contacted via mintons@ozemail.com.au. 


The Wader Study people can and will trace such reports and provide feedback to the reporter. And it adds a piece to the jigsaw of knowledge of the lifecycle of wading birds.  


As my blogging colleague Mick has discussed previously, this applies even to birds flagged overseas, such as her beloved Bar-tailed Godwits, but also the smaller Waders, Stints, Turnstones and Plovers. Take note of the colour and position (Left leg, right leg, tarsus or tibia) - (see diagram if in doubt) of all "flags", and the order (top down) of the coloured flags if two or more are present - e.g. black flag over silver as in one of Mick's flagged bird photos.

Tiny flowers of Sarcochilus hillii

Unlike the large and showy flowers of my local Sarcochilus falcatus (the "Orange-blossom Orchid") these tiny flowers of the related Sarcochilus hillii are exquisite in delicate colour and form - but tiny.

Sarcochilus hillii

According to my guide for the day, Alan Stephenson, these flimsy plants are referred to as "twig epiphytes", meaning they grow in the very finest of branches of their favourite host tree the Grey Myrtle (Backhousia myrtifolia). 

In some cases their manner of growth reminds me of the "Tangle-root Orchid" (Plectorrhiza tridentata) often growing by means of roots holding the plant up to the branch above it, because the roots are stronger than the flimsy, (often dead) twigs on which the plant has grown. Here is a case in point. The flowering plant is growing by roots connected to the branch above, while the twig on which it is growing is broken.

Sarcochilus hillii - growing as a "Twig Epiphyte"

These plants were mostly growing on the damp stems of small Grey Myrtle bushes.
 

Sarcochilus hillii growing on smallish Grey Myrtle tree.

Although there were some of thee Orchids growing on moss-covered rocks on the ground below these trees. In the Shoalhaven Valley area - 30 Kms west from Nowra - (where we were) the Grey Myrtle mostly grows as a dense thicket along wet creek lines. In this creek the myrtles stopped about 50 metres from either side of the creek. The Sarcochilus hillii plants stopped with the edge of the Myrtle thicket.