Hello Possums!

I imagine that most of my Australian readers will recognise the allusion in the title, but for anyone else you could search for 'Dame Edna' on your favourite search engine or, perhaps more sensibly, just ignore it! This was to be quite a short post relative to some of my recent ones, partly because I don't have all the photos I'd like for it, and also because the three-part Alphabet of National Parks which began in my last post is something of an odyssey, and we'd probably both appreciate something a bit less substantial. However, a couple of my friends have come to the rescue regarding photos - it's curious that I, who have no artistic bents, have artists among my friends and Kathy Walter and Julian Robinson are among those friends who are much better photographers than I. Kathy in particular is also a mammal aficionado. Their photos are acknowledged as we go; those without acknowledgement are mine. I am very grateful to them for making this a much better post than it would have been.

Before we get to the Australian possums which are the subject of today's post, a quick revision of the origins of marsupials. Perhaps counter-intuitively they seem to have arisen in North America, with the oldest fossil which is definitely that of a marsupial being from Utah and dated at 80 million years ago. From here they spread throughout Eurasia presumably via a land bridge where the Bering Strait now is. It seems that they reached South America about 65 to 55 million years ago, perhaps by the hypothetical Aves Ridge (it exists, but its above-sea history is debated). Here they flourished while elsewhere the rise of the eutherians eventually spelled the fall of the marsupials. From South America marsupials, perhaps just one species, reached Australia via Antarctica about 50 million years ago. 

Big-eared Opossum Didelphis aurita, Trilha dos Tucanos, a lodge in the Atlantic
rainforest inland from Sao Paulo, Brazil. It seems appropriate to offer you a Brazilian 
species here, as it was from here that the American opossums first became known in 
Europe, when Vicente Pinzón presented one to the king and queen of Spain in 1500.

All this is really to say that the numerous American opossums, for which our possums were named, are only very tenuously related. (You will read elsewhere that the Virginia Opossum is the only opossum in North America, but this is untrue - there are eight species in Costa Rica for instance; the previous statement should include 'north of Mexico'.) These species, or their ancestors, moved north from South America when the Isthmus of  Panama rose to join the continents together just three million years ago.

White-eared Opossum Didelphis albiventris, Iguacu Falls, far southern Brazil.
The word 'opossum' is apparently from the Powhatan language of what is now Virginia.

When this officially became 'possum' in Australia is surprisingly unclear. I generally find Edward Morris's 1898 Dictionary of Australian English helpful in such matters but from it I can only deduce that 'opossum' was still the formal term here at that stage, but that 'possum' was being used less formally. Oh well, I don't suppose it matters here!

I suspect that to most eastern Australians at least 'possum' means the Common Brushtail Trichosurus vulpeculus. In fact I was prompted to post on possums by the appearance one morning recently of an adult Brushtail sleeping the day away just outside my study window on the balcony in an uncomfortable-looking site formed by the gap between the heat pump for the house heating and cooling, and the brick dividing wall between us and the neighbours. 

Brushtail Possum sheltering by day on our balcony, presumably because s/he couldn't find
an appropriate hollow (or had been ousted from one). It has now moved on and I hope is
sleeping more comfortably!

Given the short time they've had to adapt to our cities compared to other large urbanites such as raccoons and foxes, I suspect that this may be the best-adapted (or rather fastest-adapted) larger urban mammal in the world. In my experience they are much commoner, or at least easier to see, in cities than in the bush. 

 

But where do possums fit into the world of Australian marsupials? (You can skip this bit without losing the thread if you want, but I'll be brief.) There are some 230 species of marsupial in Australia, New Guinea and nearby islands, and roughly 110 in the Americas. In Australia there are four Orders - the carnivores, the bandicoots, the herbivores (wombats, koala, possums and kangaroos) and the two extraordinary species of 'marsupial mole'. Possums and kangaroos together form a Suborder, also with four groups; the pygmy-possums, the gliders and ringtails, the brushtails and cuscuses - and all the kangaroos! Yep, kangaroos are just the ones who stayed on the ground. It seems that their distant ancestors, the oldest Australian marsupials that we know about, were small carnivores, some of whom took to the trees to access the fruits and flowers up there. In time (at least 35 million years ago), some of them came down again to live on the ground as herbivores and became the ancestors of the wide range of kangaroos, wallabies, potoroos etc.  

Musky Rat-kangaroo Hypsiprymnodon moschatus, Lake Eacham, Atherton Tablelands,
tropical Queensland. This is the smallest and most ancient living kangaroo, and 
perhaps gives us an idea of the ancestral kangaroo.

Those ancient marsupials which stayed in the trees became the ancestors of the modern possums, which form three subgroups (Superfamilies, but let's not go there) of some 70 species. While it's worth remembering that the kangaroos etc are as closely related to the possums as each of the possum sub-groups are to each other, we're otherwise ignoring them today. (But for a lot more about them, see here.)

The largest group, with about 35 species in four families, comprises the gliders and ringtails plus the tiny Western Australian Honey Possum and Feathertail Glider - about half of these are Australian, the rest are from New Guinea and associated islands. Remarkably it seems that gliding, a means of moving between trees without being exposed to the hazards of having to come to ground, has evolved on three separate occasions within this group. Two of the families have both gliding and non-gliding members, while the Feathertail Glider is alone in its family (though it may actually represent two species). There are about 17 species of ringtail, of which six live in Australia. The most familiar of these overall is probably the Common Ringtail Pseudocheirus peregrinus, found all along the eastern seaboard though there is probably more than one species involved here too. It is a much quieter and less pugnacious species than the Brushtail with which it often cohabits in urban situations.

Common Ringtail Possum Pseudocheirus peregrinus, Deua NP, southern NSW.
I unfortunately seem to have missed the characteristic white-tipped short-furred 
prehensile tail here. It has a long bare gripping pad below and acts as
a fifth limb both in climbing and carrying nesting material. They build
characteristic spherical grassy nests, in hollows or foliage, which are
called dreys after similar structures built by squirrels in Britain. In southern Australia
a Common Ringtail is likely to have several dreys in its home range; in the tropics 
it's more likely to use a tree hollow.

 

The Western Ringtail P. occidentalis of south-western Australia is sometimes lumped in with the Common. 

The other ringtail species (in different genera) are all tropical, including three with very small ranges in north-east Queensland rainforests.

Green Ringtail Possum Pseudochirops archeri by the famed and much-visited Curtain Fig
near Yungaburra on the Atherton Tablelands inland from Cairns. It typically hunches like
this to sleep on a branch in the open. Its greenish fur is due to an unusual blend
of white, black and yellow hairs. 

There is also a fascinating rock outcrop specialist ringtail, the Rock (or Rock-haunting) Ringtail Petropseudes dahli from the sandstone country of the Top End of the Northern Territory and the Kimberley. They spend the day sheltering among the rocks but forage at night in trees.

Right among the various ringtail genera is Petauroides, a group of three species of Greater Glider (until recently lumped as one species P. volans). Their gliding membrane stretches from the elbow to the 'shin' (or tibia) and with it they can cover distances of 100 metres, making turns of up to 90 degrees and flattening at the last moment to hit the trunk of the target tree vertically. Because of this attachment it doesn't spread its arms out while gliding but sticks out its elbows and tucks its paws under the chin.

Southern Greater Glider P. volans, Boonoo Boonoo NP, north-eastern NSW. A truly
beautiful mammal, one of only two (along with the Koala) to live almost solely on
eucalypt leaves - an awful diet but a guaranteed one. Unlike most other possums they are
almost entirely silent. The colour is very varied and near-white individuals are common.
Photo courtesy Kathy Walter.

A second family within this grouping comprises most of the rest of the gliders - the 'wrist-winged' gliders - and the enigmatic and striking tropical Striped Possum.

Striped Possum Dactylopsila trivirgata, Lake Eacham, Atherton Tableland,
tropical Queensland. This is probably the most visually spectacular of possums;
this one, plus three other species, are also found in New Guinea. This lodge on
the edge of Crater Lakes NP attracts these and Sugar Gliders in the evenings by
applying honey to the trunks in front of a small 'grandstand'. This would normally
make me very uncomfortable but the animals are clearly not dependent on the
offerings; some nights they don't come at all and they don't come at predictable times.
Moreover, the Striped Possum is largely carnivorous.

This fuzzy blow-up features the greatly elongated fourth toe which is critical to its
foraging for wood-boring beetle larvae, an important food source. Its two adze-like
lower incisors chew away the wood and bark, and the toe (or its long tongue)
hooks out the wriggling snack. This is probably the least-known of Australian possums,
though it is not uncommon in its tropical forests and woodlands.

Until recently there were four species of the 'wrist-wings' in the genus Petaurus, but now the (relatively) familiar and very widespread Sugar Glider (P. breviceps) has been split into three - and it seems that further work in the tropics may reveal even more species. The true Sugar Glider seems now to occur only to the east of Great Dividing Range; the animals west of the range (including around Canberra) are Krefft's Gliders P. notatus and the tropical savanna populations are of Savanna Glider P. ariel. My previous neighbours in inner northern Canberra had a family of Krefft's Gliders living in their roof cavity! I haven't tried to illustrate all three, as they are physically very similar.  As the group name implies they have a full gliding membrane attached at wrists and ankle and are very adept aerialists. They are small, with a body less than 20cm long and the tail about the same length again.

Krefft's Glider (almost certainly) at the feeding station at Lake Eacham. Unlike the Striped
Possums with which they sometimes feed here, nectar and other plant exudates feature in
their natural diets. They roost in hollows in family groups of half a dozen adults plus
young, and emerge together to forage. The edge of the non-extended gliding membrane
can be seen in the photo.

Other members of the genus are larger. The Squirrel Glider P. norfolcensis is a woodland species of about twice the bulk. In the south-east it is only found west of the Great Divide, but further north it comes to the coast. 

Squirrel Glider, Chiltern forest, Chiltern-Mt Pilot National Park, northern Victoria.
The very bushy tail, especially at the base, is a good identification distinction 
from the sugar gliders. 
Photo courtesy Julian Robinson.

The highly endangered Mahogany Glider P. gracilis is noticeably larger again; it is limited to a very small section of coast in the Wet Tropics of Queensland between Ingham and Tully. It was only recognised as a separate species in 1993, having been 'lost' for a century since its initial description as a separate species, which was soon after rescinded. By this time much of its habitat had disappeared, especially to the sugar cane industry.

The largest by far though of these gliders is the spectacularly active and noisy Yellow-bellied Glider P. australis. They are found along much of the east coast and hinterland and, while threatened by logging, they are still reasonably common in the south, but the tropical populations (represented by the one below) are in danger. 

Yellow-bellied Glider, Atherton Tablelands; the alert posture in typical. Its attention-
grabbing shrieks are said to be audible half a kilometre away. 
I once heard one glide past my tent in the Brindabella Ranges, with a truly
alarming gurgling wail; I have since heard that this call is only uttered 
while gliding (and is uttered during most glides) so probably has 
a function in the coordination of group movements. 
Like other wrist-wing gliders it chews holes in tree trunks to lap the sap flow.
Photo courtesy Kathy Walter.

The highly endangered Leadbeater's Possum Gymnobelideus leadbeateri of the montane ash forests of Victoria near Melbourne is in the same family and is like a sugar glider without the gliding facility.

 

Two other very small families (in species numbers and individual size) complete this group. The tiny Honey Possum or Noolbenger Tarsipes rostratus of south-western Australia is less than 20cm long including the tail and weighs less than 15g. It is entirely reliant on nectar and pollen and is an important pollinator of plant groups such as banksias. It is the only member of its family. The three remarkable photos that follow were all provided by Julian Robinson and were taken at Cheynes Beach near Albany.

 

Honey Possum with its nose deeply embedded in the banksia flower spike.

Honey Possum licking nectar from the banksia flower, its tongue clearly visible.

Honey Possum with banksia pollen on its whiskers (you may have to click
on the photo to see it properly).

The final family in this grouping comprises just two species of equally tiny possums, though only one is found in Australia. The Feathertail Glider Acrobates pygmaeus is found from the south-east coast to the tip of Cape York Peninsula though its size (think a small mouse) means that it isn't often seen. (There is actually a good argument for two Australian species being involved, though that's not yet been generally adopted.) The relatively thick gliding membrane is attached to elbows and knees, and the eponymous feathery fringed tail doubtless assists in the glide too. It has insect-eating teeth and a brush-tipped pollinator's tongue. 

Feathertail Glider Acrobates pygmaeus Beowa NP, far south coast NSW. 
This is the world's smallest gliding mammal. I have spent time in the same campground 
without seeing this little beauty - note to self, be more assiduous! 
Another remarkable photo. Photo courtesy Kathy Walter.

The second group of Australian possums comprises larger animals, the brushtail possums, cuscuses and the Scaly-tailed Possum.

 

The brushtails, as I mentioned earlier, are doubtless the possum that most Australians will think of, because one species, the Common Brushtail Trichosurus vulpeculus, is found across most of the continent, though it's now very rare in the arid lands and declining in the north and south-west. However it is still an abundant urban animal in the east, and is likely to be found scrounging in most park campgrounds. Atypically among possums, the brushtails inexplicably lack the powerful gripping structure of the front feet, where the first two toes oppose the other three.

 

Common Brushtail investigating the bird feeder at night in my former Canberra 
back yard. I had three or four living in my garage most of the time and except in 
drought time they foraged away from home and mostly left my vegie garden alone.
When the Millennial Drought was at its peak though they even ate the bark off
my chilli plants; I gave up at that point. They are mostly vegetarian and eat a lot
of leaves - including some that are toxic to most animals - and fruit and flowers.
They are big animals, up to three kilograms, so need a lot of food.

While they 'normally' spend the day in tree hollows, there are simply not enough
such hollows to support the large urban populations, and like the one on our
balcony that I mentioned earlier, will make do where they can. This mother and
baby had settled into the one of the bird hides at Canberra's Jerrabomberra Wetlands.

There has long been also recognised a closely related species of the ranges, the Mountain Brushtail or Bobuck T. caninus. However in 2002 it was realised that this comprised two species, roughly north and south of Newcastle in hinterland forests; the new species, T. cunninghamii, referred to the southern animals and retained the Mountain Brushtail (or Bobuck) name (though the subsequent discovery of Victorian populations in eastern lowlands was unfortunate in this regard!). T. caninus in the north became Short-eared Brushtail (or Bobuck). Confused? Never mind, here's one to take your mind off the names! 

Short-eared Brushtail, Chichester State Forest, south of the Barrington Tops in NSW.
This one was very much at home in the campground.

In addition the isolated and distinctive coppery race of the Atherton Tablelands, and the not-very-brushy-tailed brushtails of the Top End are also considered by some to be separate species, which may well be accepted in time.

The most numerous possums within this group are the 22 species of cuscus, most of which are in New Guinea and nearby islands, though two of them are also found in tropical far north Queensland. They have distinctive short faces and long prehensile tails, and are mostly vegetarian though at least some also take eggs and small animals opportunistically. They are hard to see in the rainforest canopy and roost well-hidden during the day. 

Waigeou Cuscus Spilocuscus papuensis, West Papua, Indonesia.
This species is closely related to and very similar to the Common Spotted Cuscus
S. maculatus, found on Cape York.
 Photo courtesy Kathy Walter.

Lastly in this group is something of an outlier, the rock-specialising Scaly-tailed possum Wyulda squamicaudata of the remote and rugged Kimberley region of far north-western Australia. 

Scaly-tailed Possum at Bachsten Camp, Kimberley.
During the day they rest in rock piles and crevices such as this, and 
forage for plant material at night, mostly in trees.
Photo courtesy Kathy Walter.

Finally the third group of possums comprises just five species of tiny pygmy possums (though some would include them in the previous group). They are mouse-sized, with long prehensile tails and occupy habitats from heathlands to wet forests and tropical rainforests, and to alpine boulder fields in the case of the Mountain Pygmy-possum, Burramys parvus. This one has a total, non-continuous range of only some 600 hectares in the Australian Alps, so is at extreme risk from climate change - once you've been driven by rising temperatures to the top of the mountain there's nowhere else to go. The other four are not regarded as nearly so precarious. They are mostly insectivores though some take nectar and the Mountain Pygmy-possum eats hard seeds. 

The story of the discovery of the Mountain Pygmy-possum deserves retelling. In 1966 a strange mouse-like animal with a prehensile tail was captured in the University ski lodge at Mt Higinbotham in the Victorian Alps. Back in Melbourne it was held at the Fisheries and Wildlife Department and examined by Norman Wakefield, a scientist and pioneer biology communicator who’d actually been working on Burramys fossils that he’d recently found in East Gippsland. He looked at the teeth and immediately recognised the living animal from the fossil. The following telegram was sent to mammal doyen David Ride in Perth. "BURRAMYS EXTANT STOP NOT REPEAT NOT EXTINCT STOP LIVE MALE CAPTURED MOUNT HOTHAM STOP AM TRYING FOR FEMALE."

Later in his book Guide to the Native Mammals of Australia, Ride wrote with passion and allusion of his reaction to that telegram. “Burramys had come to life. The dream dreamed by every professional palaeontologist had come true. The dry bones of the fossil had come together and were covered with sinews, flesh and skin. Burramys lived”. This seems to me a wonderful and wholly appropriate expression of joy from a senior, and sometimes dour, scientist.

Eastern Pygmy-Possum Cercatetus nanus, Beowa NP, above and below. This one is
somewhat atypical in mostly eating nectar and pollen, and is known to be a significant
pollinator of banksias and waratahs. 
Photos courtesy Kathy Walter.

This post has turned into a longer journey than I'd planned (as is often the case I find!) but I hope you've enjoyed the ride and found something of interest and pleasure along the way. And I hope you love our possums as much as I do!

NEXT POSTING THURSDAY 6 NOVEMBER

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Corymbia; ghosts, blood and spots!

This is my first post for a while as we've been exploring the wonders of south-western Queensland, as I mentioned in my last post. We brought back plenty of material for future posts, but for now I'm going to offer something different while I sort out my photos. I also thought this one might be a relatively easy one with which to ease myself back in (my mind is still back with big blue skies, huge horizons, narrow roads stretching out of sight ahead, and surprises round each corner). However, as usually happens in such a situation, it's been a lot more work than I'd realised, as I discovered how much I didn't know and, with new knowledge, came across a couple of misidentifications in my photos. All for the good, I know.

Today I'm talking about an important group of eucalypts, including a few pretty familiar ones, which are no longer called Eucalyptus. That might sound contradictory, but in fact 'eucalypt' is a general name to describe any of the trees that have at some time been called Eucalyptus; they remain as closely related to each other and as instantly recognisable as they ever were.

Flowers of Red Bloodwood Corymbia gummifera, here at Tianjara Falls in Morton
National Park inland from Nowra, south coast NSW. There are a couple of issues here
that are relevant to today's post, the first being the way the flowers are clustered. You may not be
able to see it well here, but the relatively flattened shape of each flower cluster is caused
by the different lengths of the flower stems within the cluster. The lower stems are longer
than the higher ones, so the overall shape is flat, or only slightly domed. This, in botanical
terms, is a corymb, which is different from the way in which other eucalypt flowers grow,
hence the genus name - more on that in a couple of paragraphs time!

The other thing to note in the above caption is the name of the tree. 'gummifera', naturally enough, means 'bearing gum' and while we may not think this remarkable, many early Europeans who encountered eucalypts certainly did. In 1688 the English pirate-naturalist William Dampier reported from the far north-west of Australia that "the Gum distils out of the knots or cracks that are in the bodies of  the trees". Governor Arthur Phillip, who commanded the first British colony on what is now Sydney Harbour, used the term 'gum-tree' in 1778; he collected this gum, and send samples back home, doubtless to have its commercial potential tested. The German botanist Joseph Gaertner first used the name gummifera in a description, but it was Daniel Solander, who sailed with Cook and Banks in 1770 and became the first university-trained botanist to land in Australia, who formally described it in 1788. 

However more than 200 years later the respected botanist Lawrie Johnson of the Royal Botanic Gardens in Sydney, along with colleague Ken Hill, grasped a very large and forbidding nettle indeed when he tackled the problem of what to do about Eucalyptus. The problem, in a gum-nut shell, is that the differences between Eucalyptus and Angophora are no greater than between the various sub-groups of Eucalyptus. Logic demanded either incorporating Angophora into Eucalyptus, or splitting Eucalyptus; Lawrie boldly chose the latter. Before his sad death from cancer in 1997 he had got as far as separating out the bloodwoods, spotted gums and ghost gums as Corymbia; they remain in most books now as the only other non-Eucalyptus eucalypt. There are four sub-groups within Corymbia; in simple terms they are the red bloodwoods (59 species), the yellow bloodwoods (11 species), the ghost gums (24 species) and the spotted gums (3 species). (There are also three outliers, but we won't worry about them today). 

That's about as technical as I'm going to get here - for the rest I'll introduce members of the four main groups and we can just admire them! Many of the bloodwoods, including those most familiar in the south-east, readily 'bleed' sap on the trunk, often encouraged by the gnawing of glider possums.

Desert Bloodwood Corymbia opaca near Windorah, south-west Queensland,
'bleeding' copiously, though not to any detriment! This species was separated
from the much more widespread C. terminalis (see below) in 1985, though
not everyone accepts the distinction.

Many of this group have plated bark, like this one, though not all.

Red Bloodwood again, near Narooma on the NSW south coast.

Pink Bloodwood C. intermedia (like most tree 'colour' names, the pink refers
to the timber, not that I've ever seen it). This one was in the Coffs Harbour Botanic
Gardens on the north coast of NSW, though it is an original tree.

These last two species are trees of the temperate south-east, though a couple of other well-known red bloodwoods are from the south-west (though are not called 'bloodwood').

Red-flowering Gum Corymbia ficifolia, in Wagga Wagga Botanic Gardens.
This small tree has a very small natural distribution in the south-west of Western Australia,
mostly along roadsides, but is very widely planted in gardens and road verges across
southern Australia. This photo shows the corymbs fairly clearly.

Marri C. calophylla, Darling Ranges near Perth. This is a very impressive
tree which dominates some dry forests in the south-west, often along with
Jarrah Eucalyptus marginata. Its big hard fruits (very like those of the Red-flowering Gum
above) are key food for the Red-capped Parrot and the Endangered Baudin's
(or, more helpfully, Long-billed) Black Cockatoo, both of
which extract the tiny seeds with a thin elongated upper mandible.

Others, like the Desert Bloodwood above, are restricted to the arid inland and the seasonally dry north.

Inland, or Desert Bloodwood C. terminalis, above and below. The one above
is in Currawinya NP, in south-west Queensland, and the one below in
Boodjamulla/Lawn Hill NP in monsoonal north-west Queensland,
with torrential summer rains and arid winters.

I'm especially fond of this species, and I see it on any inland trip to the northern half
of Australia, in four of the five mainland states and the Northern Territory.

 Another closely related desert bloodwood was only recognised in 1995.

Sand Dune Bloodwood C. chippendalei, Great Sandy Desert, central eastern WA.
This one only grows on dunes in the central and western deserts.
It was named for George Chippendale, an expert on plants of the Northern
Territory and later the author of the mighty eucalypts volume of the Flora of Australia.
He was also a lovely person who delighted in sharing his knowledge with others.

Corymbia deserticola (another 'Desert Bloodwood' though without a formal English name)
also growing in the Great Sandy Desert. It has a similar distribution to the Sand Dune
Bloodwood, but a wider range of habitats though is usually found on the plains.

Other red bloodwoods grow only in the seasonal tropics.

Small-fruited Bloodwood C. dichromophloia, Boodjamulla/Lawn Hill NP.
This common bloodwood is found from north-west Queensland to the Kimberley.
It is smooth-barked except for the base of the trunk, to which flakes of old bark adhere.

(Another) Red Bloodwood C. erythrophloia, Undara Lava Tubes, north Queensland.
This very striking tree grows in eastern tropical Queensland.

The yellow bloodwoods are much fewer in number. This one is common, and especially conspicuous.

Yellow Jacket C. leichhardtii, Salvator Rosa NP, south-central Queensland
(part of the Carnarvon Range), above and below. This is its southern-most extent,
but it extends north on the western slopes to Mareeba and is readily seen on a
drive through the Queensland tropical woodlands, where sandy soil overlays sandstone.

And one familiar to readers from the Sydney region, is Yellow Bloodwood C. eximia, also found only on sandstone, from Nowra to the Hunter Valley.

Yellow Bloodwood, here at Glenbrook in the Blue Mountains
(and I really must get a better photo of this species!).

There are just three species in the spotted gum group, including the well-known Queensland endemic Lemon-scented Gum C. citriodora - well known because it is widely planted in southern Australia. I used to walk to university in Adelaide through a large stand of them in Botanic Park. However further south by far the best known spotted gum is, wait for it... Spotted Gum C. maculata, which grows all along the NSW coast south from Taree. It is a lovely and readily recognisable tree for its blotchy bark, caused by grey flakes of old bark sticking to the trunk. Here are three Spotted Gum portraits from the south coast of NSW - I'm very partial to them!

Spotted Gum forest along a walk to the beach, Murramarang NP.

Tall old Spotted Gum near Nowra - I couldn't get far enough away to fit
it all into a conventional photo.

Spotted Gum forest with typical understorey of Burrawang cycads,
Macrozamia communis, near Nelligen.

Finally, the last group of Corymbia comprises the wonderful ghost gums, which I blogged about in more detail seven years ago here. By far the best known is the Ghost Gum of central Australia, from eastern WA to western Queensland.

A Ghost Gum C. aparrerinja, estimated to be at least 300 years old, at Trephina Gorge,
eastern Tjoritja (MacDonnell Ranges). For more photos of this very beautiful species,
and some interesting information I was given about the origin of the unusual
species name, see the link immediately above.

Ghost Gum by the road west of Windorah, south-west Queensland.
This must be close to its south-eastern limits.
(It occurs slightly further east to the north of here, at Barcaldine.)

Other ghost gums occur in the tropics.

Rough-leaved Ghost Gum C. aspera, Boodjamulla/Lawn Hill NP. The species is
found across the northern tropics from here in north-west Queensland to the Kimberley.

Ancient C. blakei in Bladensburg NP in central Queensland, growing on
a substrate too hard to penetrate with its roots! It is restricted to this part of Queensland.

Two others in the ghost gum group are very striking trees from eastern Queensland, though to my frustration my photos don't do them justice. Oh well, I'll just have to go back!

Dallachy's Ghost Gum C. dallachiana, Barcaldine. This is a young tree (and drought-affected)
and doesn't give much indication of how handsome it will grow up to be!

And we end with another favourite of mine, the stately Carbeen, or Moreton Bay Ash
C. tessellaris. Heading north we encounter this tall white tree with a rough grey or black
bark stocking in northern NSW, and it continues right up to Cape York.

Well, if this topic didn't interest you much, you won't be still reading! For those who are, thank you for persevering and I hope you learnt something of interest (I certainly have) and at the least enjoyed some of the trees themselves. Next time I'll be back with a more general posting, almost certainly based on one of the lovely parks we've recently spent time in, in south-western Queensland.

NEXT POSTING THURSDAY 8 AUGUST

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The Vanishing Woodland Birds

This somewhat unsettling post is prompted by a truly uplifting event which seems to be still ongoing in Canberra. We are revelling in an influx of Swift Parrots, one of Australia's most threatened bird species.Years go by here without more than a handful of sightings; some years we see none. This is in itself not necessarily a cause for concern as on the mainland they are woodland nomads, following the flowering of the boxes and ironbarks in particular across the countryside. However we know that numbers are perilously low, and falling. 

Swift Parrot Lathamus discolor, Mount Majura, Canberra;
an exquisite little bird which we see all too rarely.

 

The temperate grassy woodlands of south-eastern Australia are one of our most threatened habitats, and were once one of the richest - this is why they were selectively settled early, grazed (and overgrazed), cleared and, worst of all, ploughed. More recently, in places like Canberra, suburban sprawl has chewed up more of the shrinking habitat. (To be fair, recent governments here have made an effort to conserve remaining woodlands and habitats, though the current one seems sadly uninterested. Across the border in much larger New South Wales, the situation is dire.)

Yellow Box Eucalyptus melliodora and Blakely's Red Gum E. blakelyi woodland in the
northern ACT. A woodland is characterised by trees more scattered than in a forest,
so that grasses form a significant part of the understorey.

These two tree species dominate the local woodlands, along with a couple of other species found more to the west of here - the ACT is on the south-eastern edge of the great swathe of woodland that once covered thousands of square kilometres on the western slopes of the Great Dividing Range, from Queensland to South Australia. It has been authoritatively estimated that less than 5% of the original Yellow Box - Red Gum woodland remains, and much of that is unprotected. Remarkably the Mulligans Flat - Goorooyaroo Nature Reserve in the north of the ACT, at just 1600 hectares, is the largest reserve of this habitat in Australia (and thus the world of course). 

 

Blakely's Red Gum, just north of the ACT.

Yellow Box, Campbell Park, Canberra.
One of my favourite tree species!

 

Of the very significant area of this woodland which includes White Box E. albens (not in the ACT) only 0.1% is reliably estimated to be largely intact.

Comparatively, the ACT has done fairly well with woodland reserves over the past couple of decades, but there is little of the necessary connectivity. Fencelines and road verges are cleared or just 'tidied', paddock trees are felled or just eventually just die, firewood collection, overgrazing, overburning and weeds all take their toll and the woodlanders which don't wander are trapped in their little patches. Such small populations will invariably die out in time.

Given this, it is almost inevitable that any species which relies on the habitat to a significant extent will be in trouble and this is what this post is about; a brief introduction to those woodland bird species in this part of the world which are listed as threatened with extinction under either ACT, national or NSW legislation. Recognising a problem, and meeting the victims, is a first step to addressing it. Most of these species, while decreasing, are probably not facing immediate disappearance, though complacency would be very dangerous and sudden population crashes are not uncommon, as we'll see. A few though are in serious trouble, especially two nomads, including the Swift Parrot. 

 

It has other problems in addition to the loss of the woodlands. Uniquely among the woodland specialists, it breeds in tall wet Blue Gum E. globulus forest in south-eastern Tasmania and in autumn crosses the hazardous Bass Strait to winter in the mainland woodland remnants. And those Blue Gum forests are being logged at an alarming rate, mostly on private land. Moreover, and bizarrely, the little Sugar Gliders Petaurus breviceps, which were introduced to Tasmania in about the 1830s, have taken to preying on nests, chicks, and even brooding females in the nest. This was only recently recognised and is a serious problem; for instance it is calculated that 65% of breeding females are killed by Sugar Gliders each year! (It occurs to me that this means that every year most breeding females are likely to be young and inexperienced, but I don't know how much of a problem this is.) Trapping of gliders by means of nest boxes is being trialled. Protection of forests on islands, especially Bruny Island, where gliders are absent, is critical. 

 

Sugar Glider; a seemingly unlikely and hitherto unsuspected assassin.
This one was a long way from Tasmania, in north Queensland.

 

Twenty years ago it was estimated that around 2000 Swift Parrots survived, but numbers were falling then. More recently genetic analysis suggests that the number of breeding birds could be as low as 300 and it is listed, nationally and by the relevant states, as Critically Endangered.

The Canberra influx in the past few weeks has thus been refreshing. Just before the rains came and the flock scattered, there was a count of around 50 birds at Callum Brae Nature Reserve in southern Canberra - in the context of the overall population estimate this is remarkable. Moreover good numbers have been reported elsewhere in Canberra, especially near Mount Majura woodlands. A friend has just told me of half a dozen in suburban Turner, near the Canberra city centre (next to where I lived for 27 years without seeing one!), so there are doubtless more around. We can only cautiously hope that it's a sign that the work being done in Tasmania is paying off. 

Part of a flock of Swift Parrots at Callum Brae a couple of weeks ago, preening in the early
morning sun. I never expected to see this many again, and the number of young birds
among them is heartening.

The other Critically Endangered woodland nomad is the Regent Honeyeater Anthochaera phrygia.  In some ways its plight seems even greater than that of the Swift Parrot, because we don't really know why its numbers have crashed so dramatically compared with other woodland species. Into the 20th century this dramatic bird (which we now know to be a small wattlebird) was present in flocks of hundreds and even thousands from South Australia to southern Queensland. Now there are perhaps 400 left, scattered and wandering from Victoria to northern New South Wales.

[Since I wrote the above I received a comment from regular reader Roman in Canberra, drawing my attention to the book Australian Honeyeaters by the curiously named Brigadier Hugh Officer in 1964, a work I don't own. In it he states “It has stood up successfully to the encroachment of settlement and can still be found in Melbourne’s inner suburbs, while, in Bendigo, it is a bird of city gardens.” So the population crash has been even more sudden - well within my lifetime for instance - than I had appreciated. Roman's full message can be seen in Comments below.]

Regent Honeyeater, Watson, suburban north Canberra, January 2020.
I first saw the species in 1992; in the 29 years from then to now I've seen exactly seven
birds, over five observations. This was the most recent, sadly just a single bird which
stayed for a couple of weeks.

It seems that they require high quality woodland with continuous nectar flow - sadly this scarcely exists any more. Ominously it seems that as the numbers fall the situation spirals; individual birds are easily hounded away by miners and Red Wattlebirds, though Gould commented on their pugnacity when in company. I've also read it suggested that breeding might require a colony, but we really don't know. Targeted tree plantings are numerous and many good people are working to save them. If I may quote myself (from my book Birds in their Habitats, CSIRO 2018): "it’s like watching a medical team fighting a steadily losing battle in the emergency department". Desperately sad in other words, and what can you do for a few hundred birds that wander over thousands of kilometres and disappear for years from a place they seemed to like? I really fear that we may see the Regent become the first Australian mainland extinction since the Paradise Parrot.

How I hope that this was not the last Regent I'll see and, more importantly,
that people will stil be enjoying them long after I've gone.

There are no local woodland birds listed as Endangered (a category between Critically Endangered and Vulnerable) mercifully, but there are seven listed as Vulnerable (ie to extinction, unless the situation changes). One of these is also a nomad, the beautiful and scarce Painted Honeyeater Grantiella picta. Unlike the previous two species however, this one roams across much of inland eastern Australia, following the mistletoe fruiting. However there is also a poorly-understood migration of at least some birds in winter to the north-eastern inland tropics. That is, it is not limited to the box-gum woodlands, and again we don't understand just what's caused its decline though it certainly seems to prefer more intact, less fragmented woodland. I've not seen many, and don't have any good photos; here are a couple of examples! Both were taken in 2013 when a few appeared in flowering mistletoes along the Murrumbidgee Corridor NR near Canberra, and even bred.

Painted Honeyeater in River Oak Casuarina cunninghamiana.
The characteristic yellow wing bar is barely visible here.
The mistletoe Amyema cambadgei, whose foliage mimics that of the Casuarina,
was fruiting heavily here at the time.

Painted Honeyeater on a nest; you're looking at its bill, eye and throat.
I include it here solely because it's so rare to see it.

Two other birds on the list are migrants, so it could be that factors in their winter non-breeding northern range are part of their problem. Superb Parrots Polytelis swainsonii are deserving of their hyperbolic name, simply stunning. They may also be bucking the trend and staging a recovery - or perhaps it's just that having been driven into Canberra suburbia during the 'millenium drought' of the early 2000s they learned that living is easier here and have returned to the city every year since, giving us an inflated idea of their numbers. 

Male Superb Parrot feeding on Acacia baileyana seed pods,
Mulligans Flat NR, northern ACT.

Superb Parrots breed in woodlands in old hollow-bearing trees to the north of the ACT, and many now come into the suburbs for the rest of summer. Then they return to their wintering grounds in the Gwydir and Namoi River catchements of the north-western slopes of NSW. This is cotton country and there is some concern that agricultural chemicals are part of their decline. (There is a separate population, seemingly not migratory, in the Red Gum forests along the rivers of the Riverina in south-western NSW. These birds have been badly affected by logging of the Red Gums, though there is better protection now, especially across the border in Victoria.)

White-winged Trillers Lalage tricolor are more conventional migrants, breeding in the south-eastern woodlands and wintering in the tropical north. It was a bit of a surprise when they were listed as Vulnerable, but those determinations are made by an independent scientific committee and based on substantial data. We should trust the numbers rather than our subjective impressions, and the Canberra Ornithologists Group has built up a very impressive data base of records over the decades.

White-winged Trillers, female above, Barkly Tablelands, Northern Territory,
and male below, Campbell Park woodlands, Canberra.
In the tropics males moult their snappy uniforms and resemble the females.

The other four listed local Vulnerable species are largely sedentary, staying here all year round, though at least one of them moves up and down from the ranges. In their cases loss and isolation of woodland remnants is the only likely cause for their decline. 

Scarlet Robin female Petroica boodang, Narrabundah Hill, Canberra.
This species mostly moves into the lower ranges in summer to breed,
and comes down to woodlands and dry forests around Canberra for the cooler months.

Scarlet Robin male, Black Mountain NR, Canberra.
They really are a stunning little bird, but the local numbers show
a sharp decline in recent years. They don't like suburbia either,
so retreat as the houses advance.

Another local robin is in even more precipitous decline, though it is still doing OK to the west and north-west of here. (That is no reason for complacency though - extinction is the cumulative effect of many populations, like little lights, going out one by one. It is rarely a single cataclysmic event.) Australian Robins were named for the (very superficial) resemblance of the Scarlet Robin to the entirely unrelated European Robin; unfortunately yellow, and even black and white, robins then appeared, but it was too late to change the name then!

Male Hooded Robin Melanodryas cucullata, south of Canberra.
A striking little bird, common across much of inland Australia,
but seemingly disappearing from the ACT. It has gone from most
of its former local strongholds over the past decade or so.

The Brown Treecreeper Climacteris picumnus is in even more trouble here; its future in the ACT seems very limited. I used to be able to find them with some confidence in several ACT woodland sites but not any more. Worryingly it seems to have gone from Mulligans Flat NR, despite a lot of work to enhance habitat (they love a lot of branches and logs on the ground) and even reintroductions from elsewhere. The last good population was in the Glendale Crossing and Old Boboyan Road section of Namadgi National Park in the south of the ACT, but that area was severely burnt in early 2020, and there is no evidence yet that I know of that the species has survived there. It too is still doing well further inland though.

Brown Treecreeper, Newline Quarry site, 2006. This was a good site (though isolated) for them, but
they've been gone from there for some years now.

Varied Sittellas Daphoenositta chrysoptera are found across much of Australia, but in a series of distinctively coloured subspecies. They are the only member of their family in Australia, with another in New Guinea. They are engaging little industrious gleaners of small prey on tree trunks and branches, which they probe with their upturned bills. They are highly sociable. Numbers reported have been dropping steadily as the non-reserved woodlands decline further.

Varied Sittella, Campbell Park, above and below.
This one briefly displayed its glorious distinctive chestnut wing bars.

Showing its strong uptilted bill, clutching lunch.

I am also going to include three species which are resident in the ACT and, while not listed here, are regarded as threatened across the border in NSW. Maybe they really are doing better here, or perhaps the data was insufficient to list them at this stage or maybe there are subtle differences in the criteria between the two jurisdictions. The fact is they are clearly in some sort of trouble, and woodland deterioration is the key factor. My subjective view would be that at least two of them have declined in the ACT in recent times.

Diamond Firetail Stagonopleura guttata, a truly lovely little grass finch which I don't see
nearly as often these days.

Speckled Warbler Pyrrholaemus sagittatus, an attractive little ground dweller
which is not seemingly in too much trouble here, but because of its decline in NSW it
needs to be watched carefully here too. This one was nesting in
the woodland patch behind the Namadgi National Park visitor centre.

Male Flame Robin Petroica phoenicea, high in Namadgi NP. It breeds in banks among
the Snow Gums and spends winter in woodlands around Canberra. Perhaps we're not
seeing much decline here yet, but caution is needed too.

I hope this hasn't been too depressing - I really don't believe that all is lost for most of these birds, but we need to be aware of the situation and to understand it as best we may. And when the Swift Parrots come we must welcome them - for our sakes rather than theirs, as they don't care much about us - and take fresh hope and inspiration from them.

Swift Parrot, Callum Brae NR.
The great ornithologist John Gould in the 1840s described
small flocks of them flying over Hobart ‘chasing each other with the quickness of thought’
(hence the name by which we know it). Maybe it could happen again.

NEXT POSTING THURSDAY 3 JUNE
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