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'), 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.

Wednesday, 26 November 2014

The Australian National Botanic Gardens Revisited; exciting developments

I introduced our National Botanic Gardens, to me the pick of our national institutions, early last year in a couple of postings, beginning here. At around that time an exciting and ambitious plan was put into execution to develop a 'Red Centre' garden, featuring plants and landforms of the central deserts. This was an apparently outrageous proposition in a city 600 metres above sea level and hundreds of kilometres to the south-east (ie towards the south pole) of the region being modelled, and with heavy acidic clay soils. But the Gardens horticulturalists seemingly have help from Hogwarts (or an Australian equivalent) and are able to grow anything, no matter how preposterous the idea - a rainforest gully for instance, including tropical trees, in a city where winter temperatures can drop to minus 10 degrees centigrade, and droughts and 40 plus degree summer days are the norm. 

To provide suitable habitat 900 tonnes of red sand, 800 tonnes of rock and 380 tonnes of brown sand were accessed from various sources (again, none of them from the desert!).
Early days in the development of the Red Centre garden, from February 2013. The red granites were laid, and soil dug
out to be replaced with sand. The mature eight metre high Red Cabbage Palm Livistona mariae on the left was brought by
semi-trailer from Queensland (not from the wild!).
I have delayed writing about the Red Centre garden until now, to give it time to get established. In truth it might seem a bit slow in parts, for the reasons suggested above, and the low nutrient sandy soils introduced for verisimilitude. Nonetheless I think it's looking great, and will get even better as time goes on. I took a series of photos 12 months ago and retook them just now, to allow comparison of progress.
November 2013 above, and November 2014 below.
The spinifex (or porcupine grass Triodia sp.) rings have grown beautifully;
they are vital habitat in the arid lands for a wide variety of small animals,
and dominate more than 20% of Australia's area!


November 2013 above, and November 2014 below.
Again the growth, this time of shrubs, is impressive.

November 2013 above, and November 2014 below.
Again the shrubs are doing well, and while the soil may look bare, it's important
to remember that many desert plains die back after flowering, and regrow from seeds
or underground structures after the next rains.

November 2013 above, and November 2014 below.
Here the growth is less evident, but it has definitely come on.
The disc in the centre is a beautiful embossed indigenous art-inspired sculpture.
These shots were taken from the raised viewing platform visible at the top left of the
first pair of photos above.

Another feature is this ephemeral sandy creek bed, planted with River Red Gums Eucalyptus camaldulensis.
I love this red sand dune too - it's bigger than it looks here. The flowering grevillea on it is
labelled as G. albiflora, but as the name suggests that has white flowers. Though I hesitate to contradict
the gardens botanists, it does look more to me like Sandhill Grevillea G. stenobotrya.(Any comments welcomed, though I'm about to go away for a while and may not be able to respond until late next month.)
A closer view of the palm - now looking a lot happier than it did soon after being transplanted - with
a family of young palms in front of it.

More verisimilitude - a termite mound (with flowering Solanums behind).
I don't assume that the mound is inhabited though...
And finally, a delightfully quirky addition, probably mostly intended for kids, though I don't accept that it's all theirs!
Thorny Devil Moloch horridus. This rendition is beautifully biologically accurate, though a couple of orders of magnitude bigger than the original which, despite the fearsome name, is a slow gentle little predator of ants.
(I acknowledge that the ants may have another view.)
Before I leave this however, I want to mention briefly another Gardens innovation which only opened yesterday - a daisy garden! (Bear in mind that these gardens feature solely native plants.)
I am interested that they have come out and backed Asteraceae as the biggest plant family;
I'd thought that the jury was still out on the on-going contest between daisies and orchids,
but I'll happily concede this one.
Just a couple of shots, which I'll repeat also in the future to allow comparison of development.
Already pretty impressive, and I gather that much of the planting was done by gardens volunteers.

Spectacular Swan River Daisies Brachyscombe iberidifolia from Western Australia.
If you're in the area, now or in the future, do yourself a big favour and drop by! In these seemingly bleak times in Australia, this is something we really can be proud of.

Next time I'll resume the pink theme begun last time - in fact it's going to be an all-pink December!


Friday, 21 November 2014

Thinking Pinkly #1 - birds

It's been a while since I offered a new colour in my very intermittent 'colours in nature' series - the last was green, found here, and you can track it back from there.

Way back someone asked me to be sure to do a posting on/in pink one day, and of course I promised to do so; it's been on my conscience (intermittently at least) ever since. Pink is generally a colour based on pigments, and especially carotenoids; we discussed them when we looked at red in nature some time ago, and the same principles apply. In general animals can't produce carotenoids but must take them from food, be it plants, algae or bacteria, then convert them, an outrageously extravagant thing to do just to look good. And never mind the strange Western tradition that reserves pink for girls - in many animals not only do the boys also flaunt it, but in some birds in particular they reserve it for themselves. 

A final comment, before the featured birds (I'll offer some other animals next time, then some flowers). I've been very conservative in what I've selected as 'pink'; there is after all a continuum that includes various reds, orange, russet, pink and mauve. Someone in my home sees colours in that part of the spectrum differently from me, so if I'm not cautious I risk domestic scorn at my colour sense...

Pink isn't actually abundant in animals; I guess the logic is that if you're going to go to all that trouble and energy expense you might as well do it properly and go for something really lurid and red. 

The most obvious pink bird of course to most people is a flamingo. I talked about the details of flamingo pinkness back here, so I won't go through it again, but it's all due to the carotenoids in its brine shrimp diet.
American Flamingo Phoenicopterus ruber, Isabela, Galápagos. Exquisite.
Some of the other more spectacular pink birds are found among Australian cockatoos.
Part of a large flock of Galahs Eolophus roseicapilla, Forbes, New South Wales.
These glorious cockatoos are abundant, having spread south-east in the past 50 years with the
spread of grain crops and water points. They are often dismissed as 'just galahs', but deserve better.
Major Mitchell's Cockatoos Lophochroa leadbeateri, Bourke, New South Wales.
An even more beautiful and much less common cockatoo of the inland.
Major Thomas Mitchell was a 19th century explorer who brought them to the public attention
by rhapsodising over them.

Both pink cockatoos in one tree, Buldbodney State Forest, central New South Wales.
Other bird feature pink, rather than fully clothe themselves in it.
Western Bowerbird Chlamydera guttata, Alice Springs.
The spectacular pink nape is only shown when the bird is displaying.
Pink-eared Duck Malacorhynchus membranaceus, Canberra.
A single-species genus of the inland waterways of Australia, the pink 'ear' is really only
visible through a telescope - or on a dead bird, which was doubtless how it was named.
Other species have pink on exposed skin, rather than feathers. This makes sense given the cost of producing carotenoids and the fact that feathers are moulted once a year. But if you refer back to the flamingo portrait above, you'll see that it favours pink all over - bill and legs, as well as feathers.
Australian Pelican Pelecanus conspicillatus, Nowra, New South Wales.
In part the pink bill pouch is due to blood vessels near the surface, but this is probably not
applicable to the bony upper mandible.

African Penguin Spheniscus demersus, south of Cape Town, South Africa.
The pink patches here definitely owe much of their colour to blood vessels;
when it's hot, more blood is directed there to assist in heat loss, so they're brighter pink.
Southern Caracara Caracara plancus, far southern Chile.
It's not a matter of losing heat down there!
Finally, a couple of examples of very attractive (to me, but probably more importantly to others of their species) pink legs.
Swallow-tailed Gull Creagrus furcatus, Genovesa, Galápagos.
A beautiful bird all round, from the pink legs up, and the world's only nocturnal gull.
Black-necked Stilt Himantopus mexicanus, Isabela, Galápagos.
So, pink is not as easy to find examples of as red, say, but it's worth looking for. Next time, a few other pink-bearing animals, mostly reptiles.


Monday, 17 November 2014

Walking Watarrka; the King's Canyon Rim walk

After a couple of postings reflecting some personal highlights of my recent trip to Ecuador, it's probably time to come a bit closer to home for this one. 

The George Gill Range lies 300 kilometres south west of Alice Springs in central Australia, and about the same distance north-east of the more famous Uluru-Kata Tjuta National Park. It was named in 1872 by one of the toughest of all 19th century European desert explorers, Ernest Giles (who will surely feature here one day in his own right), somewhat prosaically for his brother in law, George Duff Gill of Melbourne, who helped finance the expedition. The western end of the range, covering some 72,000 hectares, has since 1983 been protected as Watarrka National Park.
Views of the George Gill Range, above and below, from the north.

The walk of some seven kilometres around the rim of Kings Canyon, the best-known feature of the range, is very much a favourite of mine, though I only 'discovered' it relatively recently. The creek which flows through it was also named by Giles, for a Mr Fielder King, though we know little of him other that he lived on a property that Giles had visited, and Giles regarded him as an "old and kind friend".

The walk features both exposed arid land forms, many of them dramatic, and surprisingly sheltered oases in gullies in the rock. It begins with a fairly daunting stone stair case climb to the plateau, but thereafter it is an easy walk on level ground until a long undulating descent.
A section of the climb; it takes about 15 minutes, but it's always good to get the worst part over first!
Looking back from the top of this climb, giving an idea of the ascent, to Kings Creek flowing into the plain.
The hard pure sandstone of the plateau is some 50 metres deep and is believed to have formed from wind-blown dunes some 360 million years ago; very little soil is found on the plateau.
Route of the walk near the start, on pure Mereenie Sandstone.
To the right is dramatic cross-bedding on the surface of the 'beehives' which characterise the plateau.
This crossbedding (detail below) is regarded by geologists as further evidence of a wind-blown dune origin.

Later (around 320 million years ago) a dramatic period of mountain-building tilted and thrust up iconic forms such as Uluru and Kata Tjuta, and forced fault lines into the Mereenie Sandstone. These fault lines formed cracks which weathered and eroded into the modern beehives.
The 'beehives' provide some of the most dramatic aspects of a dramatic walk.

By contrast, the walls of the canyon itself, seen from above magnificently from vantage points along the route are sheer for the top 50 metres at least.
The hard sheer Mereenie Sandstone walls of the canyon.

Below the Mereenie layer is an older, softer, redder one of Carmichael Sandstones,
formed  under a sea 440 million years ago.
These are crumbling and undermining the Mereenie layer, causing huge boulders to fall from the walls.
The plateau is a tough environment but inevitably plants thrive there, though the going is obviously hard in same instances.
Ghost Gums Eucalyptus (or Corymbia) aparrerinja, above and below.

Here the Ghost Gum roots are sprawling across the surface seeking access to water.
Also searching for water on the rocks are the roots of this Rock Fig Ficus brachypoda.
Baeckea polystemmonea, another shrub clinging for life to the rock face; flowers below.
This is a generally uncommon species, but is readily found along the walk.

Acacia macdonnellensis, limited to the central desert ranges;
the name comes from the nearby MacDonnell Ranges.
In the sheltered depths of the gorge itself however, and in one particular rocky gully along the walk, conditions are dramatically different, cool and sheltered, and life is very different.
Known locally as the 'Garden of Eden' (!), this mini-gorge supports River Red Gums (Eucalyptus camaldulensis)and MacDonnell Ranges Cycad Macrozamia macdonnellii (also below), a relict of ancient wetter times.
MacDonnell Ranges Cycad with male cones.
Animal life is less evident in these exposed conditions (especially with lots of walkers) but it is there.
Little Eagle Hieraaetus morphnoides on a nest on the canyon walls.
Spinifex Pigeon Geophaps plumifera, an exquisite dryland pigeon of rocky areas.
Grey-headed Honeyeater Lichenostomus keartlandi on Grevillea wickhamii.
Ring-tailed Dragon Ctenophorus caudicinctus.
A beautifully camouflaged grasshopper - though it doesn't seem to have saved it from losing an antenna!
This brief posting really doesn't do justice to one of Australia's great walks, but hopefully it will at least encourage you to add it to your 'must do' list - it deserves to be there.