Category Archives: Wetlands

Broughton Pea

While 2021 hasn’t quite matched 2016 as a ‘wet year’, nor come even close to the amazing events of 2010-11, it has nonetheless been well better than average.

As a result there are a few wetlands across the Moolort Plains holding water and that has resulted in some notable observations.

This small freshwater meadow at Baringhup West is one of my favourite spots. It lies at the base of a gentle basalt rise and the wetland itself is dotted with lots of volcanic ‘floaters’ – it has never been cultivated and has been conservatively grazed over generations.

A brilliant purple flower caught my attention on a recent visit, one that I can’t recall seeing on the wetland previously. It is Broughton Pea Swainsona procumbens, a species that is rare in the district, but more common further north where it can be found in areas of heavy clay soils that are prone to seasonal inundation. Like many of the native peas it is extremely palatable to stock – its saving grace is that it can flower and set seed before grazing animals can get access to it.

Broughton Pea has featured previously on Natural Newstead, after Dawn Angliss found a specimen in 2009 at the Castlemaine Golf Course – click here for Frances Cincotta’s article.

The return trip home was also of note, a Spotted Harrier floating over the ripening canola and a pair of Swamp Harriers just south of Picnic Point, a species that is uncommon locally.

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Freshwater meadow, Baringhup West, 6th October 2021

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Broughton Pea

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Spotted Harrier

Where once there were thousands

From almost anywhere on the southern expanse of the Moolort Plains, the most prominent landmark is the impressive Mount Kooroocheang, a large volcanic cone near Smeaton.

Yesterday afternoon it formed part of the backdrop as I sat beside a small lignum wetland on the plains. A flock of Glossy Ibis, seventeen in total were feeding in the shallows of the ‘gilgai-pocked’ wetland, occasionally taking flight as a Swamp Harrier floated through and disturbed the peace.

These days it is a rarity to see this species on the plains, they arrive only in wet years and stay only as long as there is permanent shallow water to sustain their favourite habitat for chasing invertebrate prey. Glossy Ibis are highly nomadic and will travel vast distances across the continent in search of such places.

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Glossy Ibis, Moolort Plains, 2nd October 2021

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The entire flock of seventeen birds

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Settling into a small patch of flooded Lignum wetland

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Glossy Ibis flock, with Mount Kooroocheang in the background

At one point the flock wheeled in front of Mount Kooroocheang and I was reminded that there was once a large freshwater wetland at the foot of the mountain, to the north-east. Almost 100 hectares in size, this wetland was apparently drained some time after 1948. The first image below (a present day pre-1750 EVC map) shows the extent of the wetland (the blue blob in the centre of the image). The next image, from Google Maps, clearly shows the current drains (just south of the patch of remnant bush) in what would have once been a glorious freshwater wetland. The final image, a 1948 aerial photograph, again clearly shows the shape of the wetland, but no sign of drainage – my guess is that it would have been a pretty much fully-functional wetland around this time. In wet years, it would have hosted flocks, not of mere dozens, but thousands of waterbirds, including that beautifully iridescent wanderer, the Glossy Ibis.

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Pre-1750 EVC map of Koorocheang area (source: NatureKit 2.0)

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Satellite image of Kooroocheang – 2021 Google Maps imagery

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Aerial photograph of the Kooroocheang area – 17th September 1948

Footnotes:

  1. I’d be keen to learn more about the history of Kooroocheang Swamp
  2. Local historian Barry Golding has written extensively (and beautifully) about this area, with a focus on the period of the first three decades of contact between Dja Dja Wurrung people and the invading, mainly British ‘explorers’, squatters, ex-convicts and economic refugees – click here.

Familiar friends and a mini-mystery

The bird in the image below has me somewhat confounded.

It’s clearly a tern, but which species?

I spotted it late yesterday afternoon on the Moolort Plains. As I quietly watched a distant feeding Brolga, it must have passed directly over my head, observed briefly in fading light as it headed north.

Whiskered Terns are the most commonly observed birds from this sub-family (related to the gulls) and can be seen in wet years on freshwater wetlands and regularly on Cairn Curran, along with the much larger Caspian Terns.

It was a fleeting glimpse but this individual looked intriguingly like a Gull-billed Tern Gelochelidon nilotica, a reasonably common species in northern and southern Victoria, but one that I’ve never observed locally. The overall appearance was of a bulkier bird than a Whiskered Tern, with less buoyant flight. Adult breeding Whiskered Terns have a black cap and nape, as do Gull-billed Terns, but have a red bill, not black and their underparts typically are sooty. The upper parts of the Gull-billed tern are almost white, rather than grey. Another clear difference is the bill shape – slender, with a less pronounced ‘gull’ conformation than the G.nilotica.

I’ll put this observation in the maybe category for now and would be interested in any reader thoughts. Sadly, the image below is the best one I have!

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A mystery tern … maybe?

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Nankeen Kestrel (female)

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Brown Falcon

Postscript: The view from a number of expert birders is that the tern is in fact a Gull-billed Tern, a rare visitor to central Victoria. One was reported at Lake Eppalock (near Bendigo) on the 9th September.

A Brolga on the plains

What a wonderful sight to observe a Brolga once again on the Moolort Plains. This area is home to a small number of pairs, perhaps no more than two, an isolated population between its stronghold in south-western Victoria (635 birds were counted there in 2019) and the northern Victorian irrigation region, which supports reasonable numbers of Brolgas (probably less than 100 individuals).

While I’ve received regular reports over recent years this is my first observation since around 2016 – the last time the Moolort wetlands held a significant amount of water.

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Brolga, Moolort Plains, 1st August 2021

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Birds and landscape

The sight of flocks of birds winging their way across a volcanic landscape evokes ‘images’ of times long past. These Black Swans would have been in their hundreds, accompanied by Brolgas, ibises and a myriad of ducks.

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Black Swans in flight over the Victorian Volcanic Plain, Tullaroop Reservoir, 17th April 2021

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Australian Shelducks

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Great Crested Grebe

Musk Ducks at Tullaroop

It’s a while since I’ve visited Tullaroop Reservoir.

The weedy shallows at the northern end of the storage have a nice selection of waterbirds at present, including good number of Musk Ducks and Great Crested Grebes.

Musk Ducks are fascinating birds. Despite their apparently limited powers of flight they are capable of moving reasonable distances in search of suitable habitat and once a good location is found they’ll stay for many months if conditions remain to their liking.

They are carnivorous, feeding on aquatic invertebrates, including yabbies and mussels and will even take baby ducklings apparently. Diving for their prey they can remain under water for a number of minutes, surfacing at a different spot which might be 100 metres from where they originally dived. The male is unlike any other local duck, with a large, leathery lobe that hangs beneath the bill. Females lack this feature but share the stiff, spiky tail of the male. Blue-billed Ducks have a similar tail but the bill shape is quite different – the bill of the Musk Duck is somewhat triangular while Blue-billed Ducks have an elongated, concave bill.

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Musk Duck, Tullaroop Reservoir, 18th April 2021

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Female Musk Duck preening

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Almost vestigial wings

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That distinctive tail

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Musk Duck with yabbie

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Musk Duck aggression

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End of an amazing journey

Earlier in the week I was poking around the wetlands at the southern end of the Moolort Plains, near Campbelltown.

Whilst the Red-gum wetlands are dry, there are some low-lying freshwater meadows holding water and attracting a nice range of birds. Black Swans are nesting, various species of ducks (Grey Teal and Pacific Black Duck are most numerous), herons feeding in the shallows (White-necked and White-faced) as well as good numbers of Black-winged Stilts.

A lone Common Greenshank Tringa nebularia was a nice surprise. This species is a summer migrant from the northern hemisphere (they breed in Siberia). In Australia it is most abundant on the coastal fringe but good numbers can be found inland as well. I see one or two most years around Newstead and hope to get a closer look this season. This individual was about 150 metres away when I spotted it amongst the stilts..

Common Greenshank, Moolort Plains near Campbelltown, 26th August 2019

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Black-winged Stilt

Black Swan on nest

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Just add water …

What a difference a drop of rain makes!

As mentioned previously it hasn’t been a particularly wet year, but just enough to encourage a few local freshwater meadows to spring into life.

Just how birds such as the Black-winged Stilt find these oases is a mystery to me  … clearly not to the birds.

Black-winged Stilt, Moolort Plains @ Campbelltown, 19th August 2019

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White-necked Heron and Yellow-billed Spoonbill

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A Black Swan event … sort of

The black swan theory or theory of black swan events is a metaphor that describes an event that comes as a surprise, has a major effect, and is often inappropriately rationalized after the fact with the benefit of hindsight. The term is based on an ancient saying that presumed black swans did not exist – a saying that became reinterpreted to teach a different lesson after black swans were discovered in the wild.

The theory was developed by Nassim Nicholas Taleb to explain:

  • The disproportionate role of high-profile, hard-to-predict, and rare events that are beyond the realm of normal expectations in history,  science, finance, and technology.
  • The non-computability of the probability of the consequential rare events using scientific methods (owing to the very nature of small probabilities).
  • The psychological biases that blind people, both individually and collectively, to uncertainty and to a rare event’s massive role in historical affairs.

Last weekend I visited a lovely shallow, freshwater wetland on the Moolort Plains, at the southern end of the plains near Campbelltown. Two things surprised me, firstly that the wetland was close to full (it’s been an ‘average’ winter but not especially wet), and secondly, that there were five active Black Swan nests scattered across the wetland. This is a great result and demonstrates the ability of this species to breed opportunistically when conditions and habitat are suitable.

Black Swan on nest, near White’s Swamp on the Moolort Plains, 4th August 2019

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Black Swan sentinel

Poise and grace

One species that has been conspicuously absent during a wet winter and spring has been the Great Egret. During our last wet period (2010-11) individuals could be seen reliably on larger wetlands and around the shores of Cairn Curran, but not so until recently.

It was no surprise though to finally observe one at Cairn Curran last week, a lone bird fishing in the shallows near the highway bridge at Joyce’s Creek. On Sunday evening I spent a glorious half-hour with one (possibly the same individual) at Picnic Point.

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Great Egret, Picnic Point, 26th February 2017

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