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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'), run tours all over Australia, and for the last decade to South America, 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 the 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.

Thursday 11 April 2024

The Pilliga; one of New South Wales' great forests

On the north-western slopes of NSW, some 400km inland, is a mighty forest and woodland covering some half a million hectares (5000 square kilometres) of sandstone. It is divided roughly 50:50 between reserved land and state forest (subject to logging). The reserved areas comprise Timmillallie and Pilliga National Parks, Pilliga Nature Reserve and Pilliga East and Pilliga West State Conservation Areas (see map below). The Newell Highway, one of Australia's busiest inland highways which provides the NSW section of the main route between Melbourne and Brisbane, passes through the forest for nearly 90km. This accounts for most of the distance between the towns of Coonabarabran and Narrabri, and makes for a beautiful drive, but it's better still to make time to leave the highway and drive onto the quieter forest roads. Off the highway to the west, Barradine is home to the excellent visitor information centre. The Pilliga is a favourite destination of ours, though I realise we've only camped there twice - so much else to see and do! And I really can't believe that it hasn't previously featured in one of my blog posts.

A typical roadside scene in Timmillallie NP, with Pilliga Box Eucalyptus pilligaensis
in the centre of the photo, and White Cypress Pine Callitris glaucophylla on the right.

The Pilliga is approximately at the end of the red arrow, inland
of the Great Dividing Range. See the next image for more detail.

The Pilliga forests as shown on Google Maps. You might need to click on it
to see properly, but the Newell Highway runs east of north up the centre
of the forest. For scale, the road distance from Coonabarabran in the south
to Narrabri at the very top of the map is 120km.

I'm afraid this is the best I can do to show you the reserves within the forest; click on it
to enlarge, to compare with the previous satellite image. Coonabarabran is at the lower
number 3, while Baradine is behind the left-hand number 4. Everything else that shows as
forest on the satellite photo is state forest. Courtesy NSW NPWS, where you
can also see the map much more clearly.

In the Pilliga State Conservation Area, just south-west of Narrabri, 5800ha have been protected from feral predators (ie foxes, cats and dogs) by 32km of predator-proof fencing, in a partnership project between NPWS and the Australian Wildlife Conservancy. It is planned to rerelease seven threatened mammal species which are now locally extinct, and as far as I can tell so far three (Bilbies, Bridled Nail-tail Wallabies and Brush-tailed Bettongs) are already established. To clarify, those three have definitely been released and others may have been since the undated article I've been reading. For obvious reasons the area isn't open to the public, though there are occasional guided 'open days' so it would be worth your while enquiring if you're interested.

The previous photo of the trees pretty much sums up the forest, in that it is dominated by cypress pine and box eucalypts, though of course in an area that big there is plenty of variation. Most of the photos that follow are in Timmillallie NP, west of the highway.

Again there is cypress pine here, but the ironbarks (these are probably
Red Ironbark E. sideroxylon) are also an important component.

A nice, though somewhat isolated, stand of ironbarks at Salt Cave Dam. Unfortunately
there's not much understorey here but the walk from nearby Salt Caves Picnic Area
passes through some very nice flowery heathland.

Belah Casuarina cristata, an important species in woodlands of the western slopes.

Brown Bloodwood Corymbia (or Eucalyptus) trachyphloia.

This is typically how most of us see the 'inside' of the Pilliga, on the excellent grid of
forest roads that cut through it. (The cloudy day here isn't so typical though.)
The roads themselves are generally good, built on soils eroded from
sandstone, so usually (but not always!) accessible.

The sandstone itself isn't so easy to find, but an excellent example is east of the highway at Sandstone Caves, an important cultural site and a nesting site for Peregrine Falcons. It is near the southern end of the Pilliga Nature Reserve.


Typical sandstone cliffs at the site, where a walking track circumnavigates the
impressive outcrops. Note the burnt tree trunks, which I'll get back to soon.
Windblown caves, like the ones above and below,
are fascinating (and very attractive) features of the cliffs.
Needless to say these shelters were of considerable importance to the Gamilaraay people who lived here for many thousands of years. This significance is reinforced by the presence of petroglyphs in some of the shelters, though they're not mine to interpret of course.
Petroglyphs, Sandstone Caves, above and below.
Another good encounter with sandstone can be found in Dandry Gorge, the site of a lovely walk that begins at the excellent low-key Sculptures in the Scrub picnic ground and campground, the only one in Timmallallie. The campground name refers to a series of sculptures along the top of the gorge, by and with Gamilaraay artists and advisors. I'm normally not keen on artwork in a national park/nature reserve (nature doesn't need help), but  I think the cultural significance here alters things. The 3k loop walk passes along the top of the cliff then descends into the broad gorge to return to the start.
View across Dandry gorge from the cliff top walk.
Inside Dandry Gorge.
When we did it (in August) the flowering was excellent, but I'll get to the plants soon.

A dry forest system such as dominates in the Pillliga is prone to wildfire and is adapted to a regime of it, but things are changing as we interfere with natural climatic systems. There have been two major wildfires in the Pilliga in the last six years. In January 2018 (two and a half years before we were last there) nearly 600 square kilometres (60,000ha) burnt, that is more than 10% of the entire forest, including much of Timmallallie. I pointed out burnt trees by the Sandstone Caves above, but the was stark evidence of the conflagration in most places where we were. 

View from the Sandstone Caves cliffs, August 2020

The heathland at the Salt Cave area was very intensively burnt in 2018,
but recovering as expected two and a half years later.

Callitris regrowth (with heavy early morning dew) at the Sculptures in the Scrub campground.
Callitris is mostly killed by fire and regenerates from seed.
Then in December 2023, since we were last there, a very intense fire burnt at least 120,000ha, nearly a quarter of the forest, mostly to the north of the earlier fire. I haven't seen the results (the area was only reopened to the public a few weeks ago), but it will be hard to do so for a while. Fortunately (and with good planning) the predator-proof area for threatened species in the north of the forest - see earlier in this post - was not directly affected by the fire.

Here are a few animals we eoncountered over the years - nothing particularly unusual, but they're all worthy of note.

Lace Monitors Varanus varius are common in dry forests and woodlands. They
do go further inland than this, especially along water courses, but are not
as common there. This big chap was cooling off in a dam.

They are excellent climbers and investigate tree hollows for potential prey.
This one went up the ironbark trunk...
... and then came down again.

Peron's Tree Frog Litoria peronii is widespread in south-eastern Australia,
and its mad cackle is a familiar night sound.

Feral Pigs are of course an environmental problem anywhere in Australia.
This family was disturbingly undisturbed by us across the dam.

And a few common birds, but nonetheless worth presenting.

Collared Sparrowhawk Accipiter cirrocephalus, a fierce little bird-predator,
found throughout the country.
Noisy Friarbird Philemon corniculatus, a big (and yes noisy) migratory honeyeater.
Red-capped Robin Petroica goodenovii, a glorious tiny inland robin
(and a pretty sketchy photo!).
Male Rufous Whistler Pachycephala rufiventris, another common migrant
whose songs fill the drier forests and woodlands from spring to early autumn.
But I'm going to finish with some plants, because the flowers in spring and autumn really are a delight in the Pilliga. Many of these species are found widely in sandstone and sandy soils of the western slopes, however I'm going to start with one which is a Pilliga endemic, and not very common even there. We found this one - and most of the others here - along the cliffs above Dandry Gorge.
Hibbertia covenyana, which was only described in 1990 from plants
collected from the side of the Newell Highway.
Golden-top Wattle Acacia mariae, a NSW endemic found in woodlands in the
north-east quarter of the state. The Pilliga is a noted site for it.
Pilliga Wattle Acacia pilligaensis, originally described from the Pilliga,
but also found in sandy soils from Dubbo to southern Queensland.
Mudgee Wattle Acacia spectabilis (confusingly also called Pilliga Wattle),
found widely in dry forests and Callitris woodlands on the western slopes
of NSW and in south-east Queensland.
Spurwing Wattle Acacia triptera, a hard spiky wattle which grows in
sandy woodland and heathland west of the Divide in eastern Australia.
Whorled Zieria Zieria aspalathoides Family Rutaceae; like many Pilliga plants
this one is found more widely on the western slopes, though in this case
from Victoria to tropical Queensland.
Sandstone Boronia Boronia glabra Family Rutaceae; again found on sand or sandstone,
north from Grenfell into south-east Queensland.

Scaly Phebalium Phebalium squamulosum Family Rutaceae; grows on sandstone
throughout much of eastern Australia
Family Lamiaceae, a mostly aromatic family which includes many of the Mediterranean culinary herbs, is well represented.
Granite Mintbush Prostanthera granitica, a not particularly common shrub
which grows in scattered rocky situations (though not always granite) on
the western slopes. This one was at the Sandstone Caves.
Prostanthera howelliae has no common name that I'm aware of, so it is not abundant.
Another one seemingly restricted to sandstone soils of the slopes.
Chloanthes parviflora, another plant not common enough to warrant an accepted
English name. A similar distribution, though scattered, to several previous species.
Grooved Dampiera Dampiera lanceolata, Family Goodeniceae;
a familiar plant with a very wide distribution from northen NSW
to far western South Australia.

Purple Beauty Bush Dampiera adpressa, a much less common Dampiera
than the previous one.

Seven Dwarfs Grevillea (I love it!) Grevillea floribunda, a delightful
small shrub which is widespread on the western slopes.

Homoranthus flavescens, a lovely little shrub in the Myrtaceae family,
another restricted to sandy soils, but only in north-eastern NSW.

Small-leaved Daisy-bush Olearia microphylla is widespread in dry forests
from Canberra to southern Queensland.

Western Wedding Bush Ricinocarpos bowmanii, Family Euphorbiaceae,
scattered in dry forest across the inland slopes and onto the plains.

Narrawarra Burr Solanum cinereum Family Solanaceae (ie tomatoes, nightshades etc).
Pretty much confined to NSW, where it is widespread on the slopes. It is not
welcome in grazing country as it is toxic to stock.

Leafy Templetonia Templetonia stenophylla. Apparently scattered widely west of
the Divide, this one surprised me because the only other Templetonia I know
has bright red flowers!

I don't think I've taken enough photos to really show off the forest, but in many ways it's a subtle beauty which I must try harder to bring to life in future trips. I hope I've been able to do enough though to encourage you, next time you're driving up the Newell, to stop for a while in the Pilliga and have a look around. If you don't yet know it you might be pleasantly surprised.

Spring in the Pilliga. Pilliga Box over wattle.

NEXT POSTING THURSDAY 2 MAY
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