Living on the Nullarbor

In the last posting I waffled enthusiastically about the wonderful Nullarbor Plain, and summarised the drive across in terms of the physical environments and vegetation encountered. Needless to say there is plenty of wildlife to see too, though much of it is small and tends to keep its collective head down out of the wind and out of view.This is not true of all animals though.

Dingo, Canis lupus dingo, east of Nundroo.
These Australian wolves can be seen anwhere, at any time of the day. See here for more information.

Crimson Chat Epthianura tricolor, Head of the Bight.
Note that Australian chats have no relationships with anything called a chat in other lands;
we now know in fact that they are true honeyeaters.

Birds however are probably more evident in the treed sections either side of the treeless plain.

Major Mitchell Cockatoo Lophochroa leadbeateri, near Nundroo.
This truly glorious cockatoo is thinly scattered across the arid inland.

Yellow-plumed Honeyeater Lichenostomus ornatus, Nundroo, gleaning scale insects from mallee eucalypt leaves.

Nankeen Kestrel Falco cenchroides pair, Eucla.
The dragon lizard in the claws of the larger female on the right is a reminder that, as throughout dry Australia,
lizards are a dominant life form here.

Indeed, the animal you're most likely to see with some regularity in warm weather is the aberrant skink that I grew up calling affectionately Sleepy Lizard, but which is more generally known as Shingleback Tiliqua rugosa. They are regularly encountered crossing the road and some certainly don't get to the other side, but it does seem to me that drivers may be showing more lizard-awareness than in times past. The number of casualties seems low relative to the number of live ones seen, given that they are pretty ambling by nature, and have the unfortunate habit of stopping to threaten the car that's just passed, instead of getting off the road.

Tiliqua rugosa

Tiliqua rugosa

Tiliqua rugosaTil

One of the many endearing things about Shinglebacks is that they seem to pair for life, an unusual behaviour among reptiles - indeed among animals in general.
Much more to be said about these animals, one of my very favourites, in a post to come!

However, there is one animal, a mammal, which is probably the one that most people making the crossing between May and October make a special effort to see. These days though, thanks to the Yalata Aboriginal Community which runs the excellent interpretive centre, and the South Australian Parks Service, the effort to see this spectacular animal is minimal. In fact, I suspect this is one of the world's truly great land-based whale-watching experiences.

From this platform on top of the spectacular Bunda Cliffs can be seen at close quarters....

Tail of Southern Right Whale Eubalaena australis, immediately below the cliffs.

In May these mighty animals begin to appear in the Bight - and other southern Australian waters - having migrated north from the far Southern Ocean where they spend summer. Initially only adults are present, but by August females are starting to give birth in the sheltered on-shore waters.

Southern Right Whale with calf.
This youngster was becoming adventurous, swimming away from mum, but not for long.

At birth the calf already weighs a tonne, but on a diet of very rich milk gains 50kg a day.
A female only has one baby every three years.

They are baleen whales - that is, they sieve plankton and small animals through baleen plates,a filter of long bristles along the upper jaw.

The baleen can be seen clearly in this adult - as can the callosities, raised roughened patches of skin - which are used to identify individual animals.

The adults weigh up to 50 tonnes and are up 17 metres long. Like all the great whales they suffered terribly from over-hunting, well into the 20th century; being slow and having a body which floats after death, they were regarded as the 'right' whale to hunt by inshore whalers. Once they were in vast numbers - the Tasmanian governor once complained that their 'snoring' in the Derwent River kept him awake at night, and it was dangerous to navigate the river in winter. Numbers crashed from an estimated 65,000 - 100,000 originally to perhaps 300 in the 1920s. At least 150,000 were killed during the 19th century. A single animal reported off Western Australia in 1955 was apparently the first in Australian waters for the century. Despite theoretical world-wide protection recovery was very slow - explained in part by a later confession by Russia that they had continued illegally killing the species in the Antarctic during the Soviet 1960s. 

There may be now 15,000 Southern Right Whales in the world, a steadily increasing number; some 2,000 of those visit southern Australian waters.

A group of four Southern Right Whales from the viewing platform - truly a thrilling sight. There were at least 10 present during our visit in late September.

There are many reasons to cross the Nullarbor, as I tried to explain last time; this one alone however surely is enough.

BACK ON TUESDAY

Crossing the Nullarbor

It's nice to be back writing a post after a solid - but exhilarating - month's work in the south-west of far-off Western Australia, including an 8000 km return drive there and back. Part of that drive involves 'the crossing', still one of Australia's great driving experiences, though it's a lot easier now than when my parents did it on a dirt track back in 1947. 'The Nullarbor' is part of modern Australian folklore, though most of us would have trouble defining it. I think it's best to think of it as the vast limestone plain - the largest in the world - that stretches for some 2000km from west of Ceduna in South Australia nearly to Norseman in Western Australia (henceforth WA), covering a quarter of a million square kilometres. Others would define it more tightly as the treeless 'core' straddling the state borders. Some people even use the term very loosely to talk about the whole drive from Adelaide to Perth, but that doesn't bear close scrutiny.

The red arrow in the Great Australian Bight indicates the general area of the Nullarbor. I have shown the huge karst (limestone) plain in purple hatching, with the 'core' in blue horizontal stripes. If you enlarge the map you'll see that the Eyre Highway runs mostly through the southern fringe, some of it very close to the coast.

The somewhat twee name Nullarbor was coined in 1866 by South Australian Surveyor Edmund Delisser, who crossed to the WA border and reported a vast treeless tract; being of the Victorian era he felt obliged to invent a Latin term which essentially means 'no trees'.

Coming from the east, we leave agricultural land in the vicinity of Nundroo, where beautiful mallees (multi-stemmed eucalypts of many species) form an overstorey over the bluebushes (saltbushes of the family Chenopodicaceae) which continue west when the trees end.

Eucalyptus calcareana (the name refers to the limestone habitat) over bluebush, Maireana spp., near Nundroo.

The vast plateau we're driving across was laid down under a shallow sea - beneath the bitumen are the calcium-based shells and exoskeletons of billions of long-dead marine animals. Towards the state border the trees get fewer and the bluebush starts to take over.

Eastern edge of the plain, with only scattered trees now to break the horizon.

Soon, even those trees disappear, and a variety of low shrubs begins to completely dominate.

Low teatrees - including Melaleuca spp. - above,
and chenopods (especially bluebushes and saltbushes) below,
forming the great treeless plains.

 

Here the road is close to the shore of the Southern Ocean, forming the Great Australian Bight, and the line of the Bunda Cliffs, running for well over a hundred kilometres and up to 100 metres high, is one of the most superb seascapes in the country.

The magnificent Bunda cliffs, near the Head of the Bight (above and below).

Virtually at the border, the cliffs begin to march inland.

The Bunda Cliffs leave the coast here, at the state border, so that there is now a coastal plain seaward of the plateau.

At Eucla, just inside WA, the highway descends onto the Roe Plain, a broad coastal strip of ancient compacted dunes. For nearly 200km we drive along this plain, at the foot of the Hampton Plateau, until at the Madura pass we climb up onto the plateau again. 

Two views from the top of the Madura Pass; above, looking east along the edge of the Hampton Plateau.
Below, looking out towards the distant ocean across the Roe Plain.

As can be seen from the photos above, the trees have by now returned to the landscape; again mallees dominate.

Eucalyptus socialis woodland near Caiguna, WA.

Also near Caiguna is what is claimed to be the longest completely straight stretch of road - 146km without the slightest deviation - in Australia. (Some say the world, but I'm not claiming that! It does seem unchallenged however that the Transcontinental Railway to the north of the road is indeed the longest dead straight length of line - 480km of it.)

Start of the 146km straight, just west of Caiguna.

As you'd expect with such an extensive karst system, limestone caves riddle the landscape, though most are not accessible to the public.

Sinkhole just outside of Caiguna. Some of the caves have produced some very important fossil troves, including the only complete skeleton of the formidable marsupial 'lion', Thylacoleo carnifex.

Finally, near Balladonia, we enter the beautiful vast woodlands of the Goldfields area of WA, worthy of a posting in their own right one day.

If you get the chance to make the crossing, please do it one day (or rather, at least three days for the section discussed here!). I've done the return trip five times now, and I'm sure I'll be doing it again. If you're Australian, it's definitely an important part of the national experience. If you're visiting, it will also leave a deep impression on you. I think you'll agree with me that the experience has no need of such silly cheap gimmicks as an extended golf course - it's much too special in its own right.

BACK ON FRIDAY, TO TALK ABOUT SOME ANIMALS OF THE NULLARBOR, INDCLUDING ONE VERY SPECIAL ONE INDEED.

Apology from Australia

This is not my usual natural history posting - in fact I'm still in Western Australia, about to start the 4000km drive home tomorrow. I don't have time or facilities for a 'real' posting, but events here since I last wrote have driven me to say something to the many people in many lands who continue to surprise me by reading my offerings.

The newly elected government of Australia has already filled me - and many others I know - with shame and embarrassment. This is not the place for a polemic, but I do want to offer my apologies, as an Australian, to those who are doubtless puzzled and even offended by unfolding events here. Both major parties sought, during the election campaign, to outdo each other in abnegating Australia's moral and legal responsibilities to the displaced of the world, and this is to our deep shame. In years to come I have no doubt that a more enlightened parliament will offer an apology to those victims, as recent ones have to 'stolen' Aboriginal children.

More immediately relevant though to those who read this blog is the perplexing and alarming formal rejection of science; there is to be no Minister for Science in the new cabinet (composed almost exclusively of middle-aged white men), a concept which I find utterly bizarre. More directly they have already abolished the independent Climate Commission, the only independent source of information and advice on this most critical of issues - bloody-minded madness. There is to be no Minister for Higher Education, apparently another deliberate move towards dumbing down the country.

The future of biodiversity management can only be viewed with despondency.

This is not why you read this blog, I know, and I won't be carrying on with this theme in future. Please know however, that there are many of us here who do not feel represented by this lot, and who reject such 1950s 'thinking'.

Meantime, back with a normal posting on Tuesday 1 October, as promised!

Magnificent Murchison (the Australian one!)

I have to specify that in the title, because elsewhere in the world people are likely to think of the superb Murchison Falls in Uganda - and they too will get a turn here in due course. I am prompted by my mention in the last posting of Augustus Gregory's mapping of part the Murchison River in 1848. Both features were named for Sir Roderick Murchison, Scottish geologist and president of the British Royal Geographical Society. 

The Murchison River is the second longest in Western Australia, flowing for some 800km from the dry inland Robinson Range to the sea at Kalbarri National Park near Geraldton on the semi-arid Indian Ocean coast, much of the water coming from overflow of salt lakes which fill only during cyclonic summer rains.

The red arrow point indicates Kalbarri and the mouth of the Murchison, flowing from the north-east.

The Murchison Gorge in Kalbarri NP is just magnificent, 80 kilometres of huge red sandstone cliffs above the sharply twisting river bed, with wildflower-rich sandy dry eucalypt woodlands on the plains above.

The Murchison, in the dry season, beneath the cliffs at Ross Graham Lookout, Kalbarri NP.

Dry woodlands, typical of the sandplains of Kalbarri above the Murchison.

"Nature's Window", a wind-eroded feature high above the Murchison.

Down at river level, a quiet pool. While the level is low here, after a dry summer when the cyclones
don't bring rain this far south, the flow can stop altogether.

Mind you, it can still rain there even in the dry season!

Semi-arid Kalbarri NP woodland rapidly becoming awash!

The rocks contain some fascinating stories too.

The tubes are in fact Skolithos - casts of the burrows of  worms that lived in a shallow sea here some 410 years ago.

Another fossil here, almost overlooking the Murchison, is one of the most exciting fossil traces I've ever seen. It marks one of the first forays ashore of a major predator, over 400 million years ago in the Silurian.

These tracks are those of a eurypterid, or 'sea scorpion', the top predator of its time, which
here followed small prey ashore onto a soft muddy shore, where they had doubtless thought they were safe!

Today the predators are generally out of sight, but the wildflowers of the Murchison plains are some of the most spectacular in Australia; let me share a few of my favourites with you.

Tall Mulla Mulla Ptilotus macrocephalus, in almost unimaginably massed flowering; this species is widespread across the arid inland, but I've never seen it like this.

Pink Milkmaids Burchardia rosea,  family Colchicaceae.
One of just five species in the genus,  this beautiful lily is restricted to the Murchison area.
For more about the somewhat mysterious person it was named for, see here.

Two superb big grevilleas light up the plains too, and are not found much further afield from here.

Grevillea candelabroides, above, and
Grevillea petrophiloides (Pink Pokers) below

Wiry Honeymyrtle Melaleuca nematophylla, another magnificent massed display.

And finally, a sandplains representative of one of the most beautiful West Australian genera, the Myrtaceous Verticordias - the genus name means 'heart turner'.

Verticordia monodelpha, guaranteed to turn both hearts and heads!

Which indeed is true of the mighty Murchison itself, and the rest of Kalbarri where it ends its journey. Make a date to get there some time, preferably in late winter or early spring.

I am about to head west myself, though not this far north this time, taking a group of people to explore the rich south-west corner. There'll be lots to talk about when I get back, so please don't forget me!

BACK ON TUESDAY 1 OCTOBER

On This Day, 21 August; Augustus Gregory's birthday

Augustus Charles Gregory was born in England on this day in 1819, son of an army Lieutenant. Wounded, his father accepted a land grant in the new Swan River colony (now Western Australia, and struggling badly at the time) in place of an army pension, when Augustus was 10. He went on to become a most successful explorer, though not nearly well enough known, for reasons that I believe to be highly ironic - we'll get to that - and an unusually respected politician. His first remarkable stroke of luck was having as a neighbour the impressive Surveyor-General John Roe, who encouraged Augustus to join the department as a cadet in 1841. His bush skills and general competence led him to be appointed just six years later, still not 30 years old, to lead his first exploring expedition north of Perth, returning with reports of good grazing land and a coal seam. This led to more such engagements, including the mapping of part of the Murchison River and the opening of the country where Geraldton now stands; this was all tough country.

Murchison River, Kalbarri National Park; probably here at least still much as Gregory saw it.

While the biographies tend not to mention it, it is clear that Gregory was already collecting plant specimens and sending them to Ferdinand von Mueller, probably the greatest of the 19th century Australian botanists.

Desert Kurrajong Brachychiton gregorii, central Australia (through a rain-spotted lens!).
The type specimen was collected by Gregory in the Murchison area and sent to von Mueller, who named it.

In 1855 he led one of the great Australian exploring expeditions, the North Australian Expedition which crossed a great unknown swathe of the country from the north-west to Brisbane on the east coast, well over 5000km, mostly on foot. Crucially from a biological perspective, the company included von Mueller, temporarily unemployed while the Victorian government couldn't pay him in his position as government botanist. 16 months after setting out, the expeditioners walked into Brisbane just in time for Christmas.

Baobab, Adansonia gregorii, Gregory National Park (also named for Augustus), East Kimberley, western Northern Territory; collected by von Mueller on the North Australian Expedition and named by him for Augustus Gregory.

Gregory continued collecting for von Mueller on subsequent expeditions, notably the unsuccessful search for the tragic Leichhardt expedition in central Australia. (His lack of success wasn't surprising; Leichhardt had disappeared in 1848 - 10 years previously - somewhere between Brisbane and Perth!)

This was his last expedition and he is seldom mentioned now in the same breath as some of the other great (and a few 'great') explorers. I think he was a victim of his own modesty, humanity and excellent planning. He insisted on exemplary behaviour towards aboriginal people through his lands he passed, and planned meticulously. All of this combined to mean that his teams were content, safe, healthy and always knew where they were - none of which made for exciting news stories! Additionally he didn't talk much about his achievements, and was apparently cheerful and well-liked, which were also probably not newsworthy characteristics.

He became Queensland Surveyor-general, then Geological Surveyor, for 20 years, then entered the Queensland Legislative Assembly where he spent the remaining 23 years of his life attacking government and aligning himself with the conservative squatters' bloc. He was reputedly incorruptible and refused government ministries so as not to compromise himself.

Senecio gregorii, Lasseter Highway, Northern Territory - South Australian border.
Collected by Gregory on the Leichhardt search expedition, and named for him by von Mueller.

Would I have got on with him I wonder? In the bush certainly, but probably not in town. No matter, he was one of our greatest explorers, though unsung, and contributed his share to our knowledge of the north and dry centre. Worth acknowledging I think.

................................

Also on this day, in 1803, surprisingly - because it was more than 15 years since the founding of the British colony at Sydney - the first Koalas known to Europeans were collected from what is now the Wollongong area.

BACK ON MONDAY

Darwin's Famous (Un)Finches

It was one of the thrills of my natural history life to get off the aircraft at Baltra Airport, an ex-military base in the midst of a typically Galápagos lava field, and suddenly realise that the 'sparrows' around my feet were in fact the famous 'Darwin's Finches'. It was one of those literally breath-taking moments. 

Medium Ground Geospiza fortis and Large Ground Finch G. magnirostris, Baltra Airport; females or immatures.
Distinguishing them is not always easy, but that's not because they're hard to see!

I put the name in quotes advisedly; not only were they not referred to as 'Darwin's' until the 20th century, but we're very confident now that they're not finches. Their actual nature is still somewhat problematic, but the general consensus is that they're probably highly evolved tanagers, whose ancestors - probably like a grassquit, small and plain - blew across the Pacific about a million years ago.

In that time, under immense evolutionary pressures due to living in such an often brutally harsh environment, racked by regular La Niña droughts and El Niño flooding, some 13 species have developed, filling niches occupied elsewhere by groups including warblers, small woodpeckers - and of course finches. For a superbly vivid and rivetting account of their (ongoing) evolution, you can't go past Jonathon Weiner's wonderful The Beak of the Finch; evolution in real time. In large part this is the story of the remarkable Rosemary and Peter Grant, British biologists based at Princeton who have spent 6 months of each of the last 40 years (at least until recently) on little exposed Daphne Major, following, knowing and measuring every finch on the island. The rapidity of changes that they observed in species under such pressures is astounding. It's one of the great stories of modern biology.

Daphne Major at dawn. The expeditioners' landing place is among the low cliffs to the right; no beaches or jetties here!

Among the ground and cactus finches, adult males are black.

Large Ground Finch male Goepsiza magnirostris, Puerto Ayora. The bills are adapted for seed collection, different sized bills being suited to seeds of differing size and hardness.

Common Cactus Finch G. scandens, Puerto Ayora on Opuntia cactus. The bird relies heavily on the Opuntia, for nectar, pollen, fruit and seeds at different times of the year.

Large Cactus Finch Geospiza conirostris, Genovesa.
Similar to Cactus Finch but bigger and more heavily-built; restricted to just four outer islands.

 Living in such a precarious environment requires flexibility and the finches on different islands have adapted to a range of opportunities.

Small Ground Finch G. fuliginosa, Isla Fernandina, gleaning parasites and dead skin from Marine Iguanas.

In some birds the differences in beaks between species - which is the key difference for the most part - is relatively minor. It is reputed that the staff of the hugely significant Charles Darwin Research Centre say that "only God and Peter Grant" can claim to reliably assign a species to every bird encountered. 

The birds are famous because of their role in the growing understanding of the great Charles Darwin as to how species evolve, but the connection wasn't as immediate and clear-cut as is sometimes asserted - mythology has replaced history in some accounts. By that stage of the voyage, they had been away from home for nearly 4 years and were understandably anxious to get home. Perhaps partly because of this Darwin wasn't quite as meticulous as he generally was. At the time of his 1835 five week stay in the Galápagos he was still fairly conservative by the standards of his circle of peers and hadn't yet accepted the concept of species changing. It was another creationist, a young John Gould, who back home identified his finches as a group of closely related species; Darwin hadn't considered that separate but closely related species could exist on islands in sight of each other, and he had to scramble to identify exactly where his specimens had come from. (At the time he was more interested by the mockingbird species.)

It was another 10 years before he wrote, in the second edition of The Voyage of the Beagle: "Seeing this gradation and diversity of structure in one, small, intimately related group of birds, one might really fancy that from an original paucity of birds in this archipelago, one species had been taken and modified for different ends." This was truly revolutionary stuff.

For the rest, let me share with you some of the beak variations among other species.

Woodpecker Finch Camarhynchus pallidus, Los Gemelos, Santa Cruz, above and below.
In this species the sexes are indistinguishable. The strong woodpecker-like bill is used to probe crevices and rip bark in search of invertebrate prey. When times are tough in the dry season however, it famously fashions and uses cactus spines and fine sticks to extract nutritious items from hollows.

The massive parrot-like bill of the Vegetarian Finch C. crassirostris is employed to snip off buds, leaves, fruit and seeds, and to strip bark off growing shoots to access sugar-rich sap. Here is a female on Santa Cruz.

Small Tree Finch male C. parvulus, Los Gemelos, Santa Cruz.Its stubby curved bill is specialised for tweezering
insects and grubs from leaf and bark surfacesand extracting larvae from inside soft stems.

Sharp-beaked Ground Finch female Geospiza difficilis, Genovesa.
Genovesa offers the best chance of seeing this often elusive species; this is the one which, on the remote
outliers of Darwin and Wolf, has learnt to peck the base of booby feathers to obtain blood,
giving rise to the somewhat sensationalist name of 'Vampire Finch'.
While all sub-species have the sharp, more slender bill atypical of ground finches, the
others haven't adopted this behaviour.

Green Warbler Finch Certhidea olivacea, Santa Cruz.
A tiny bird with a small fine bill evolved for snapping up small insects.
Older books list jut one species, but two are now recognised, with
Grey Warbler Finch C. fusca restricted to smaller more outlying islands.

And there are another four; I've seen but not yet photographed Grey Warbler and Large Tree Finch and not yet seen the restricted range Medium Tree and Critically Endangered Mangrove Finch. Maybe one day. They are all fascinating birds and if you can possibly get to see them one day, I'd urge you to do so. You'll never be sorry.

Large Ground Finch, Puerto Ayora.

BACK ON WEDNESDAY