About Me

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Canberra-based naturalist, conservationist, educator since 1980. I’m passionate about the natural world (especially the southern hemisphere), and trying to understand it and to share such understandings. To that aim I’ve written several books (most recently 'Birds in Their Habitats' and 'Australian Bird Names; origins and meanings'), and run tours all over Australia, and for 17 years to South and Central America. I've done a lot of ABC radio work, chaired a government environmental advisory committee and taught many adult education classes – and of course presented this blog, since 2012. I am a recipient of the Australian Natural History Medallion, the Australian Plants Award and most recently a Medal of the Order of Australia for ‘services to conservation and the environment’. I live happily in suburban Duffy with my partner Louise surrounded by a dense native garden and lots of birds.

Sunday, 31 December 2023

Farewell to 2023!

I've now established this as an annual tradition, a review of our year as represented by one photo from each month. (As sometimes happens, at least one month passed with no appropriate photos, in which case I've presumed to 'borrow' photos from other, over-picced, months.) It was a pretty good year overall for us (though not of course for Australia, or the world at large), with our first overseas trip in four years, and our first longish holiday in our camper trailer. Anyway enough of words, here's one way of looking at our year.

And as ever I don't make any pretence to photographic excellence; I have no training and my pics are definitely records rather than art. This collection was chosen for their associations rather than any misperceived excellence.

JANUARY

This was the first time this lovely sun orchid, Thelymitra alpicola, had been reported in
the ACT (and I hasten to say that I didn't find it, but was Acting on Information Received).
It was growing in typical habitat near a bog in Snow Gum woodland, but was previously
only known from NSW in the Snowy Mountains and Blue Mountains. Even with
the aforesaid information it took me a while to find it, and I felt very privileged.

FEBRUARY

For the past couple of years it's been our practice to pack up the camper trailer as
soon as summer school holidays end and head for Beowa National Park (formerly Ben
Boyd NP) on the far south coast of NSW. On this occasion we made a day trip south
into Victoria to Croajingalong NP near Mallacoota. Our highlight there was watching,
with some enthralled campers, these two big Lace Monitors Varanus varius competing for mating
rights in the area. It was mostly a wrestle (and they were still at it when we left
after quite a while) but those claws are horrendous and there was some gashed skin too.
MARCH
In March we went to the Blue Mountains (another regular and fairly-close-to-home
destination) but my favourite image from March is this one, taken in our back yard, of a
Greenish Grass-dart Ocybadistes walkeri with its proboscis deeply into a
glowing everlasting daisy Xerochrysum bracteatum.
APRIL
In April we spent a few nights in Forbes, a town we're fond of on the south-western
slopes of NSW, some 300k north-north-west of here on the Lachlan River. On its edge is
one of our favourite wetlands, Gum Swamp. However my favourite memory-photo from
this trip is this one taken from a footbridge over Lake Forbes (an anabranch of the Lachlan
in town, now managed as a permanent lake) in the late afternoon. This Australian Water Rat
(or Rakali as it's often known now, an Indigenous name from the Murray-Darling)
swam towards us and eventually right under us, showing off its characteristic
white tail. It was a very nice moment.
MAY
Our May highlight was a camping trip out west to Mungo National Park, nearly 800km
from here on the arid western plains. It is famed as the site of the one of the oldest burial
sites in Australia, some 40,000 years old, and apparently the world's oldest cremation site.
However its 110,000 hectares have some excellent wildlife values too, and one morning
while walking near the campground I came on this Australian Hobby Falco longipennis,
breakfasting on what was I think one of the numerous and raucous Yellow-throated Miners
Manorina flavigula which dominate the area. This one's dominating days ended that
morning however, and the falcon was too engrossed in its meal to be disturbed by
my observing it.
JUNE
June was a non-affair as far as photography was concerned, which gives me an opportunity
to feature a trip we did to Lake Cargelligo in February, when after some angst on my part
the goannas got 'shot of the month' billing here. This is also on the Lachlan River 400k to
the north-west of here, where we visited an old friend. The highlight here was a veritable
cornucopia of waterbirds following flooding across the countryside. But my choice of
photo for the month is this one of a glorious Pink Cockatoo Lophochroa leadbeateri,
part of a flock feeding and squabbling by the roadside early in the morning on Callitris
Pine cones. As I watched, little groups creaked across the plains to join them
until the roadside trees were glowing pink; a wonderful experience.
JULY
In July we finally got to accompany a tour to Costa Rica, originally planned for 2020 before COVID
changed the world and ended international travel for us for four years. Needless to say there
are numerous photos I could have used but one of my abiding memories of this trip was this
extraordinary encounter with a rare, threatened and little-understood mammal, while on a
boat trip on the Rio Suerte ('Lucky River') returning from Tortuguero on the Caribbean coast.
This Neotropical River Otter Lontra longicaudis popped up from the water as we
approached and proceeded to eat its catfish lunch while we watched.
A special moment in a tour of many special moments.
AUGUST
I am glad to be able to offer two (very different) photos from Costa Rica. One morning
this amazing creature was found by one of our group in her room, from where
another of our number (hello Steve) extracted it, identified it and placed it on a
convenient tree trunk to be admired. It is a tailless whip-scorpion (an arachnid but not a
true scorpion or even a true whip-scorpion) in the Family Phrynidae, found throughout
the tropics. However I'd never seen one and was enthralled; the fact that it was at
least 10cm across helped there too! The six back legs are for walking, the front pair stretch
forward as sensory organs, and in front again are the formidable spiked jaws (pedipalps).
I saw many striking animals in Costa Rica, but perhaps none more so than this one.
SEPTEMBER
In September we did a long-planned camping trip to South Australia (my 'state of origin')
to visit three of my favourite parks there. The first one, Dhilba Guuranda–Innes National Park
at the foot of Yorke Peninsula, proved to be our most memorable. This Hooded Dotterel (or
Plover if you prefer) Thinornis cucullatus was foraging on Shell Beach, near our
campground, at dawn one morning while the beach was still otherwise deserted
(I stayed up on the dunes). This is a nationally threatened species and generally shy,
so I was thrilled by this encounter.
And as a bonus I can't resist sharing the exquisite beach it lived on, taken that same early morning.
OCTOBER
That holiday extended into October, so I can legitimately double-dip! On our way home we
had intended to make our last camp in the little-visited Red Banks Conservation Park near
Burra in the mid-north of South Australia. However that afternoon it was raining, very
windy and cold, so we opted to stay in Burra instead (for the record at the old railway station
which is well worth bearing in mind if you're there). However both mornings I went
out early to Red Banks; I saw but didn't get a photo of the Redthroats for which it is
noted, but loved being out in this semi-arid mallee-bluebush scrubland.
NOVEMBER
In November we were back in the Blue Mountains and managed to find a lovely short
walk that we hadn't done before. The flowering was mostly over, but the walk to the
Walls Lookout, culminating here in spectacular sandstone scenery at the edge of the mighty
Grose River Valley, was exquisite and memorable. It is reached from the Bells Line of Road,
then turning off to the Pierces Lookout picnic area; you can walk from the carpark by
the road, or take the shorter option from the picnic area further in.
We just love the sandstone country.
DECEMBER
In December we always spend a few days at Currarong at the north end of
Jervis Bay on the NSW south coast to celebrate Lou's birthday. It's a pleasureland of
sheltered bays, forest and heathland. For some reason I didn't take many photos
this time - probably because I already had so many from previous visits - but I like
this one, taken by Lou with my camera from the car window at the boat ramp. The
tide was full so these Crested Terns Thalasseus bergii had lost their roosts on the
rocky reefs just offshore and had to battle for individual perches at the ramp.
We are looking across the ocean to I think Mount Coolangatta in the hazy distance
(you might need to look at a map to make sense of that).
Perhaps not of general interest but good memories for us.
So once again, this was my year, or at least a version of it. Thank you very sincerely for reading my offerings, and for your support through your comments below. As I've said before, whatever is coming we can be sure that nature is always there to inspire us and keep us in perspective, and I have every intention of continuing to share it with you through these posts. May your 2024 start peacefully and naturally. My best wishes to you, Ian.

NEXT POSTING THURSDAY 18 JANUARY
I love to receive your comments and in future will be notifying you personally by email when a new posting appears, if you'd like me to. All current subscribers have been added to this mailing list and have already been contacted. This will mean one email every three weeks at the current rate of posting. I promise never to use the list for any other purpose and will never share it.
Should you wish to be added to it, just send me an email at calochilus51@internode.on.net. You can ask to be removed from the list at any time,or could simply mark an email as Spam, so you won't see future ones.
If you do leave a comment - and I love it when you do - please remember to click the
box below your comment that says 'Email follow-up comments to...[your address]'
so you'll know when I reply - and I always do!

Thursday, 14 December 2023

Sandstone; perfect building material for a landscape

This is my last post for 2023 (except for the traditional New Years Eve farewell to the year). It's a long one, though it mostly comprises photos, and is different from anything I've offered before in that it features not a particular group of animals or plants, or a place, but a type of landscape. I love sandstone and the unmistakable form it gives to a landscape and the sometimes extraordinary structures it can produce. Some of the grandest scenery I know is built of sandstone, and this post is almost entirely Australia-oriented. Overall this is intended to be a celebration of such landscapes, which I always find to be satisfying and often truly glorious.

Tjoritja/West MacDonnells from Larapinta Drive near Alice Springs, central Australia.

View from Govetts Leap of part of Blue Mountains National Park, near Sydney.
The oldest Blue Mountain rocks formed from marine sediments between 470 and 330 million
years ago. Later they were buried deep under new sediments in a shallow sea between
280 and 250 million years ago. Finally yet another layer was added by rivers carrying sand from
far to the west, between 250 and 170 million years ago.

Heysen Range from Bunyeroo Valley, Ikara-Flinders Ranges National Park, South Australia.
The Flinders sediments were laid down between 500 million and a billion years ago, in a great
trough (the Adelaide Geosyncline) in which sediments settled in layers up to 20km deep.
Of course people have long associated with and utilised sandstone for art works and building material and, while that's not my interest today, it would be foolish not to acknowledge that.
Part of the extraordinary Indigenous galleries on Ubirr Rock, Kakadu National Park
in the Northern Territory.

Petroglyphs (carvings) on sandstone in an under-cliff shelter in Timmallallie
National Park in the Pilliga forests, central New South Wales.

Sandstone outcropping, heavily quarried, by the sea in Glebe, central Sydney.
Much of the city centre and old suburbs of this, Australia's first city,
was built of this sandstone and it continued to be used throughout the
nineteenth century.
All sandstone was formed from silica particles laid down long ago, having eroded from even older rocks and been carried by rivers or the wind to form deep beds and, with the aid of the ultimate tool, time, compacted by the weight of younger material above and sometimes chemically 'glued' into stone. Later it again became exposed on the surface. I am not a geologist and have no pretensions to being one, so I'm not going to say much more about the process of formation - if you're interested there's plenty of material out there about it. Sandstone is a sedimentary rock, named for the obvious reason of comprising sediments. Finer sediments, settling in still waters, form mudstone or siltstone, while coarser ones, containing larger particles or even rocks carried along by strong currents, can form mixed conglomerates. I hope that I'm not making any errors that would offend a geologist, but I always welcome comments and corrections.

Large particles in sandstone in the gorge walls at Glen Helen, Tjoritja/West MacDonnells.

Conglomerates in the Valley of the Winds, forming the mighty domes
of Kata Tjuta. The nearby equally mighty Uluru (which we'll visit soon)
is comprised of finer sandstone, but both structures were formed
from the eroded remains of mountain ranges to the south and west.
It's not a simple 'there, it's now done' process of course, the earth is restless. Where the layers were once nicely horizontal and parallel, later upheavals are revealed in buckled and uplifted layers.

Folded sandstone along Jack's Creek in Cocoparra NP, central southern NSW.

At Uluru, many of the layers have been lifted to almost vertical,
as in the top centre of this photo.
And not all layers were placed there by the force of water; wind can do the job too. The hard pure sandstone that forms at least the top 50 metres of the stunning Kings Canyon Plateau in Watarrka NP in central Australia is believed to have formed from wind-blown dunes some 360 million years ago.
This cross-bedding, with clearly visible fault lines, provides evidence to geologists that the
origin of this sandstone was in wind-formed sand dunes.
The famed 'beehives' of the plateau formed from this structure. These fault lines formed cracks which weathered and eroded into the modern beehives which display the layers of dune sand from which they derived. 

Most of Australia's best-known mountain ranges are formed of sandstone. We've acknowledged Tjoritja/MacDonnells, the Blue Mountains and Ikara-Flinders above. Here are some more, some well known, others perhaps less so.

From Central Lookout, Stirling Ranges, central southern Western Australia.
Musgrave Ranges, on the South Australian - Northern Territory Border.

Evening on the Bynguano Range in the mulga country of Mutawintji NP,
far western NSW.

View from Mount Zero in the north of Gariwerd/Grampians NP, western Victoria.

Weddin Mountains NP from the south-east, near Grenfell, south-western slopes of NSW.
Spinifex-covered sandstone hill in the Gawler Ranges NP, north of Eyre Peninusula, South Australia.

Amunurunga Range along the Gary Junction Road west of Alice Springs near the WA border.
And of course in Kakadu National Park in the Top End of the Northern Territory we can be absorbed by some two million hectares of sandstone landscape!

A view from Ubirr Rock, Kakadu.
Similarly the Chapada dos Guimaraes, in south-western Brazil, is a landscape of sandstone, a whole vast plateau rather than a recognisable range.
Chapada dos Guimaraes, a wonderful wildness of sandstone just north of
the more famous Pantanal wetlands.
On the other hand monoliths - literally 'single rocks' - may form, ranging in size from quite small to utterly vast. (Monoliths can also be of volcanic origin.) To be honest I'm not sure of the difference, if any, between a monolith or an outcrop, and may be blurring definition boundaries here. That shouldn't stop us from admiring them though!
 
Isolated boulder, Weddin Mountains NP, NSW.
Larger sandstone outcrop (perhaps better described as a column?)
along the Victoria Falls Road, Blue Mountains NP.
Corroboree Rock, eastern Tjorita/MacDonnells. This rock is of great significance
to the Easten Arrernte people, to the extent that apparently even its 'real' name
is not to be shared.
Wild Dog Hill, Whyalla Conservation Park, South Australia.
(On reflection, perhaps an isolated hill rather than a monolith, but that raises questions
anyway! Happy to have your opinion on this one.)
And some really big ones, all from the Northern Territory I now realise.
Burrunggui (more generally known, though incorrectly, as Nourlangie Rock), Kakadu National Park.
This site was and is of huge importance to Bininj Mungguy people and contains many
significant art sites.
Ikuntji or Haasts Bluff, a stand-alone mountain at the western end of Tjoritja, some 230km
west of Alice Springs.
And of course the sublime Uluru, the greatest monolith of them all, rising out of the central desert.
Here the rock is catching the last glow of the setting sun, with purple evening
shadows gathering at the base.
An aspect of some sandstone ranges that I love forms when a layer of harder material is deposited on older softer material. As erosion of the softer surrounding material proceeds, a ridge or even a range is left standing above the surrounding plains, protected for at least a while longer by the hard resistant cap.
A capped range in Tjoritja/McDonnell Ranges west of Alice Springs.
Atila, also known as Mount Connor, central Australia. It is near the highway to the west
of Uluru, and I'm sure many people coming from Alice Springs to the west mistake it
for Uluru. I had initially featured this above as a monolith, but I'm uncertain now.
Certainly it's a single mighty lump of rock, but it's really a remnant of higher land surface,
protected by the thick cap clearly visible.
Does it matter? It's a superb part of the land whatever we call it.
Inevitably the undercutting of the cap occurs through the actions of wind and water, and smaller isolated capped outcrops are formed. In North America the term is usually mesa (Spanish for a table), but in Australia the evocative names include breakaway or jump-up (which of course is entirely a misunderstanding of the formation).
Breakaways near Coober Pedy, northern South Australia.

Mount Webb under full moon at sunset, on the southern edge of the Great Sandy Desert,
far eastern Western Australia.

Jump-up at Cawnpore Lookout between Winton and Boulia, western Queensland.
Jump-up on Theldarpa Station, far north-western NSW.
'Soon' the remnants of this protective cap will be entirely eroded away.
And what happens to the caps which are being undercut to tumble down the hillsides? Well in large areas of arid Australia they scatter across the plains to form an entire landscape of hard wind-polished stones, known as gibbers.
Gibbers near Pimba along the Stuart Highway, northern South Australia.
And of course not all such landforms are in arid country.
Didthul, later named Pigeon House Mountain by Captain Cook,
from Bawley Point on the NSW south coast.
Towards the end of their career, such jump-ups can form quite spectacular columns.
Chambers Pillar, central Australia.
Capped sandstone columns at Oldupai Gorge (usually mistranscribed as Olduvai)
in Tanzania. This area is famed as the site worked on by the Leakey family, with
local people, to cast early light on the origins of our species and those of our forebears.
Some other columns, sometimes even more spectacular, are formed differently. Sediments are laid down at different times, and meantime the earth may have tilted so that there are joining planes of different-aged sediments at different angles. These joints are potential weaknesses which may start to separate when the pressure of kilometres of overlying material is released by erosion, and water, wind, plant roots and ice will over time enlarge the joints and even split them, leading to crumbling away of some material and leaving a 'core' that can be of remarkable shapes. Bear in mind that this is a lay explanation, but it's got the gist of it. One of Australia's best-known landmarks was effectively formed in this way.
The Three Sisters formation at Katoomba in the Blue Mountains, with the
Jamison Valley as a mighty backdrop. (The oft-cited sisters 'legend'
is entirely a 20th century whitefella beat-up incidentally.)
Several sites in the Top End of the Northern Territory also feature extraordinary sandstone columns, with 'lost cities' in at least two national parks.
Along the Bardedjilidji Walk, Kakadu National Park.
Lost City, Litchfield NP, south-west of Darwin.
Above and below, Southern Lost City, Limmen NP, in the eastern Top End
(there is also a Western one in the same park).
This one shows very clearly the smooth surface of the shearing plane,
where it split; a smaller one is also visible in the previous photo.
On grander scale these shearing planes can form mighty cliff faces.
Seaside cliffs, Bako NP, Sarawak, Malaysian Borneo.
An enormous example of the phenomenon in the wall of Kings Canyon,
Watarrka NP, central Australia.
Other cliff faces aren't as 'neat, but can still be imposing.
Cliffs at Boodjamulla/Lawn Hill NP, north-west Queensland.
A mighty and rugged cliff face in the sunset at Glen Helen, in far western Tjoritja.
Sunset again, this time on the cliffs in Jasper Gorge, Gregory NP, north-western Northern Territory.
'Softer' sandstone cliffs, Timmallallie NP, Pilliga forest, central western NSW.
Such softer sandstone readily forms wind-blown caves and shelters, which have long been valued by wildlife and humans. Such formations often became art sites in pre-European Australia, and some are maintained to this day.
'Nature's Window', Kalbarri NP, Western Australia.
Hollow Mountain shelter and art site, Mount Zero, far northern
Gariwerd/Grampians NP, western Victoria.
Extensive shelter in Bomaderry Creek Reserve, Nowra, south coast NSW
It's not always obvious when a cliff becomes part of gorge, though it's reasonable to assume that a gorge will have a pair of facing cliffs - although even there the sweep of a stream may form a cliff on only one side at times. Streams wear away their beds, or penetrate and widen fault lines in them and with enough millions of years may form deep wide gorges. Such gorges are as intrinsic to the sandstone country as are cliff faces. Here are some that we've enjoyed. 
Some are large or well-known...
Looking down on the gorges of Bundanoon Creek and its tributaries, Morton NP, NSW.
Lawn Hill Gorge, Boodjamulla NP, north-west Queensland. An exquisite place.
Murchison Gorge from Ross Graham Lookout, Kalbarri NP, WA.
Ormiston Gorge, western Tjoritja, above and below.

The walk that crosses Ormiston Pound (see later) and passes through the gorge
here is one of our favourite walks in Australia (hence two photos!).

Standley Chasm, Tjoritja. I find it hard to satisfactorily photograph this narrow slot,
but that's no reason to exclude it! Tjoritja seems to have more than its fair share of
gorges, but it's probably just that many of them are accessible (and as it's one of
our favourite parts of the world we've explored it pretty well).
Some are smaller or less well-known...

Another from Tjoritja, this time Red Bank Gorge at the western end of the
national park. Good camping, a nice little walk and cooling off opportunities!

Cobbold Gorge, on Robin Hood Station (!) in the gulf country of northern Queensland.
The station offers accommodation and guided tours, including electric boat trips in
the gorge, where this photo and the following one were taken.

Ripple reflections on the wall of Cobbold Gorge. I don't do plugs
for private enterprises often or lightly, so when I do you can know I mean it.
Here is more about it in an earlier post.

Further west in Queensland is Warrigal Waterhole near Mount Isa.
More on this delightful spot here.

Nooldoonooldoona Waterhole at Arkaroola in the far north of the Flinders Ranges in
South Australia. I had to include it for the name alone! Try rolling it around your mouth.
And lastly a couple of small ones from inland NSW.
Mutawintji NP in the far west, near Broken Hill. Another special park, which I wrote about here.
Dandry Creek Gorge, Timmallallie NP in the vast Pilliga forests, on the north-western slopes
of NSW. This is part of very nice and quite easy 4km circuit walk.
And I can't believe I haven't written a post about this wonderful park yet!
Finally (and you thought this would never end, didn't you?) one more interesting landscape structure which is probably not limited to sandstones, though I can't offhand think of other examples in Australia. A pound was originally an enclosure, usually of stone or brick, in which animals which had strayed or been seized were kept until an appropriate penalty was paid. It was then applied to natural landforms, on much vaster scales, which comprised a ring of mountains. These have formed by chance of circumstances; in the case of the most famous Australian example, Wilpena Pound (Ikara to the Adnyamathanha people), there are actually two ranges involved. The scale is such that it is almost impossible to illustrate from the ground; there are many aerial photos of it on line, which I'd recommend if you're interested.
The northern walls of the pound from outside, in the Bunyeroo Valley.

Looking south across the floor of the pound from Wangarra Lookout. This is a panoramic shot
encompassing some of the ring of mountains, though the photograph of course flattens the sense
of being encircled.

Ormiston Pound; from this lookout near the start of the walk the track descends into
and across the pound, to Ormiston Gorge.

Welcome Pound, Arkaroola in the northern Flinders Ranges.
This one at least gives us a sense of the 'pound' structure.

And that is the end of a long and rocky, but hopefully enjoyable, journey through our sandstone landscapes. If you've made it this far, I thank you for persevering, it's been a long road to here. 

As I warned at the start, it's been quite different from any other post I've ever done (and there have been 530 of them), in that plants and animals haven't rated a mention, though of course the sandstone lands are rich with them. In a future post I'll rectify that and celebrate some of the sandstone flora and fauna.

Meantime I'll close this with a couple of images of one of my very favourite lumps of sandstone.

Rwetyepme/Mount Sonder, western Tjoritja, above and below in very different moods.

I'll be back on New Year's Eve, as ever, with a round-up of the year via a photo per month. Thanks again, and see you then!

NEXT POSTING SUNDAY 31 DECEMBER
I love to receive your comments and in future will be notifying you personally by email when a new posting appears, if you'd like me to. All current subscribers have been added to this mailing list and have already been contacted. This will mean one email every three weeks at the current rate of posting. I promise never to use the list for any other purpose and will never share it.
Should you wish to be added to it, just send me an email at calochilus51@internode.on.net. You can ask to be removed from the list at any time,or could simply mark an email as Spam, so you won't see future ones.
If you do leave a comment - and I love it when you do - please remember to click the
box below your comment that says 'Email follow-up comments to...[your address]'
so you'll know when I reply - and I always do!