Tag Archives: waterbirds

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August 23, 2015

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kayaking, national parks, waterways

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Paper roads, private rivers

Sea eagle at Mangrove Creek

It’s been a long time since I have had a close encounter with a tinny.  Perhaps it’s being on the river for the winter sunrise, but I’ve been finding myself all alone on the water for weeks now.

Which is mostly – in fact, almost entirely – a good thing.  But rattling down the road to Mangrove Creek last weekend,  I began to have doubts.  Could I hear the sound of duelling banjos in the distance? Was I about to make an unplanned appearance in the sequel to Deliverance?  (This is not a film to select as a fundraiser for your local canoeing club, by the way)

What was it that was freaking me out?  Was it the bags slung over the heads of the traffic lights as I crossed an abandoned stretch of the Pacific Highway? The rubble-flanked track plunging down the escarpment into the rainforest, a lyrebird breaking cover  the only thing on the road for miles around?  The isolated tumbledown houses, walled in by rusted-out cars and half-drowned boats?  The total lack of mobile coverage?  Or the large signs at every turnoff: “Private property!  Keep out, city slickers, or you WILL be disembowelled!”

Yep, that’s it: that nasty feeling that I might be chased, possibly at gunpoint, off someone’s private land.  This particular stretch of river – owned by the Crown like most tidal waterways, surrounded on all sides by national parks and serviced by public roads – is particularly tricky to access.  Glenworth Valley, for instance, a patch of acreage between Popran Creek and the National Park of the same name, offers pony riding, quad bikes and guided kayak tours  to cashed up visitors (and very nice they are too, I’m sure).  But if you want to launch your own craft from there that’ll be $50, thank you very much.  Maybe as a nation-building project we should institute publicly funded zip lines so kayakers can hurtle directly from the towering if unprofitable sandstone rockfaces in the national parks to the miles and miles of marketable creeks below.

Casuarinas besides Cabbage Tree Creek, a tributary of Popran
Gnarled vine in a secret valley by Cabbage Tree Creek
Back to Popran Creek
Almost decent picture of a shy azure kingfisher
Alien spores.
Mysterious cutting. Possibly paid for by your $50 launch fee.

It’s not getting any better, either, in NSW anyway.  The current state government is selling off thousands of Crown roads – paper roads as they’re sometimes called, since they exist mostly on maps – sketchy unformed tracks or riverside reserves, sometimes illegally fenced off, across private land.  But flimsy and flyaway as they might sound, paper roads are routes in to rivers and other wild places to anglers, bushwalkers and kayakers.  And they’re being erased from the map, to the faraway ker-ching of cash registers.  Perhaps that was the noise I heard in the distance, not red-necks with banjos, after all.

Possibly because Shooters and Fishers’ Party hold two seats in the NSW Upper House,  anglers get a once-over at the Crown roads put up for sale before they go.  Perhaps we need to set up a Canoeists, Backpackers and Assorted Outdoor Types With No Aspirations to Kill Things Party to get a gander too…. Mmmm, thinking about it, maybe the CBAOTNAKT already exists…

Contractual obligation white-faced heron in the mist on Mangrove Creek

But, without the comforting presence of my local CBAOTNAKT Member of Parliament in a kayak beside me, I was distinctly on edge last Sunday as I parked up next to a semi-collapsed shed largely supported by a jumble of discarded oil cans, non-functional bicycles and rolls of ancient carpet ideal for concealing the bodies of trespassers.  Did this private dump signify total indifference or was it the rural property owner’s equivalent of the pile of discarded undergarments on the bedroom floor, mess in a place so private you expect no other eyes on it at all?  With the valley under a blanket of mist, I hoped I wouldn’t find out.

Stumbling on an apparently abandoned riverside caravan park in the fog didn’t reassure me either.  We all know desolate motels and the like are the optimal spot for a horror movie – leaving aside sororities full of nubile sophomores, of course (I think I’m fairly safe on that front).  There was a spooky stillness about the place.

And then some ducks took off with a clatter and the channel changed.  A pair of kingfishers chased each other, squeaking and swerving in and out of the mangroves’ eves and old blokes in shorts appeared out of kitchen doors, morning coffee in hand, to have a natter and a tinker with the outboard.

I love to watch the day unfurl from its cocoon of mist.    A silence shared with a white-bellied sea eagle; the hunting herons and the whirling swallows apparitions in the cloud.  Then the fog parts and the first wattle-blossom catches in the morning light.  Before you know it, the blue river is dazzling and it’s time to go home.

White-bellied sea eagle fluffed up in the morning mist
White-faced heron making its exist
Welcome swallow and ghost
Early wattle on Mangrove Creek
The last of the mist rising off Mangrove Creek.

As I paddled the last few hundred metres to the car, I saw figures on the shore, and my heart sank.  I don’t know I was more afraid of aggrieved landowners demanding a handful of cash or a mob of ferals threatening to slash my tyres.

It turned out to be a trio of local teenage boys not old enough to have a licence, filling in their long, long, long country Sunday with a walk along the river.  They were much more sheepish to find an adult in their hangout zone than I was to be there.  And I remembered: when you’re a kid, you have no private property – everything belongs to someone else.

View up Popran Creek, towards the private property.
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July 29, 2015

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Animal communication, anthropocene, Backyard birds, kayaking, national parks, natural history, waterways

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Nine herons hunting

Striated heron fishing
Striated heron enjoying the happy moment of having caught something
Striated heron moving out of the puddle to eat its crabby prey

Nine herons hunting… could it be the beginning of a carol for Christmas-in-July?  Not a bad sound track, perhaps, for a paddle on a wintry 25th down Mooney Mooney Creek.

There were (roundabout) eight cormorants, some of them cacking….

Oyster leases in Mooney Mooney Creek
Pied cormorant telling me what it thinks of being stalked by a kayaker with a camera

… three posing pelicans

… two eagles soaring

White bellied sea eagle
Wedge tailed eagle soaring
Wedgetailed eagle showing wedgie tail
A bit of colour and uplifted wings

And a kingfisher in a mangrove tree (no photo, naturally).

The sacred kingfisher was probably in this picture of mist rising on Pile Creek though it’s hard to say

But realistically, I could only get all the way through the twelve days of anti-Christmas by including the many invisible mud-loving animals that all those herons were stalking.  And I’m not quite sure if I have the alliterative and euphonious verbs to use for them.  Twelve isopods…. idling? Eleven worms a-wobbling? Ten crustaceans crawling?

First white-faced heron for the day… look harder!

Even if it can’t offer swans a-swimming or geese a-laying, Mooney Mooney does pretty well for both visible and invisible animals, considering how damn noisy it is.

I first started dreaming about paddling this creek as we swooped above it, across the lofty freeway bridge.  It’s a gorgeous structure, if you are partial to well-formed concrete: elegantly curved, arching vertiginously above the treetops of Brisbane Water National Park.  An endless stream of cars and semis cross the valley on the F1, the main route north from Sydney, on the tallest road bridge in Australia, the still water 75 metres below.

Mooney Mooney Bridge – a beautiful bit of concrete
Mist on Mooney Mooney Creek on an earlier jaunt

The Pacific Highway, looping its way down to its own modest crossing point, has plenty of traffic too: bikers switchbacking their way up the old road. This Saturday, I didn’t see a soul in three hours on the river, but for a mile or more I could hear the hiss of compression brakes and the revving of engines.

And yet, if I had to pick a place, of all the waterways I’ve paddled so far, to find and fail to take a picture of a kingfisher, this rowdy river is the one I’d choose.  The traffic noise seems to keep the humans at bay, but not the herons.  What’s going on with the wildlife around here?

Looking back towards the Old Pacific Highway bridge

There’s plenty of evidence that traffic noise bothers birds.  I particularly like a recent experiment where researchers planted speakers in a long line to create a phantom road.  That’s just what the freeway feels like from Mooney Mooney Creek – a road you can hear all over but mostly can’t quite see.  The phantom road, with its invisible traffic masking mating and alarm calls and the sound of approaching predators, cut numbers by a quarter, and drove two species away from the area entirely.

Some cope better than others.  High pitched songs are less likely to be blocked out by the roar of traffic, and so squeaky voiced birds are more likely to hang around in noisy places.  Species with a little vocal versatility often start to sing a bit higher, a little slower or in purer tones, just to be heard.

If you’re carnivorous, being able to hear the critters scuttling around in the bushes is a boon. Seeds and nectar are less likely to make a break for it, so background noise seems to be less of a big deal for the plant-eaters.  Also, birds that feed on the ground seem to mind the noise less – perhaps there’s more obstacles between them and the din.

Everyone agrees that in loud places, birds spend more time on the alert for predators – a high maintenance lifestyle.  That said, some nest-robbers are also put off by the rumble of traffic, so for some species, chicks hatching in noisy nests have a better chance of survival.  If you can handle the decibels, you may have a competitive advantage.

What does all this tell me about the plentiful birdlife of Mooney Mooney Creek?  Thinking about it, I saw high-pitched squeakers, mud-hugging stalkers and sharp-eyed hunters (see, I’m getting into the swing of this avian carol singing thing!)  I’m guessing striated herons don’t echolocate for crabs.  This white-faced pair were happy to ignore not just the distant thunder of trucks but the much more immediate annoyance of a nosy canoeist with a camera.

“The mud is like a Christmas tree”, my eight year old said, hearing the story of my low-tide adventures, “and the bird were excited to find all their presents”.

When the eating is this good, it seems, the soundtrack scarcely matters.

References

Francis, C.D. (2015) “Vocal traits and diet explain avian sensitivity to anthropogenic noise” Global Change Biology 21(5), 1809-1820

Francis, CD and Jesse R Barber (2013). A framework for understanding noise impacts on wildlife: an urgent conservation priority. Frontiers in Ecology and the Environment 11: 305–313. http://dx.doi.org/10.1890/120183

Francis, CD, Ortega, C and Cruz, A. (2009) “Noise Pollution changes avian communities and species interactions” (2009) Current Biology 19(16) pp.1415-19

McClure, Christopher J. W. Heidi E. Ware, Jay Carlisle, Gregory Kaltenecker, Jesse R. Barber (2013) “An experimental investigation into the effects of traffic noise on distribution of birds: avoiding the phantom road”  Published 6 November 2013. Royal society proceedings B DOI: 10.1098/rspb.2013.2290

Patricelli, Gail L. and Jessica L. Blickley (2006) “Avian communication in urban noise: causes and consequences of vocal adjustment” from The Auk 123(3): 639-49

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June 23, 2015

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anthropocene, Geology, History, national parks, natural history, Seasons, Soil

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Midwinter lagoon

Bombah Broadwater in the gloaming

It’s past the shortest day of the year, but, in spite of her scrapes and dings, Egg the elderly wooden kayak doesn’t seem to be ready for drydock yet.  Perhaps it’s that last unseasonable whirl of autumnal warmth, caught alongside the coast in the East Australian Current, that’s keeping the sea a balmy 20 degrees.  Or perhaps it’s just the lure of still, winter water all around.

Since Egg was first laid in our driveway a year ago, I’ve been seeing Sydney differently.   Those long roundabout routes from A to B via M and Q and P, punctuated somewhere along the way by a bridge or two, suddenly make sense.  The city of roads and buildings retreats and, I feel, just out of sight on every side, the presence of water.
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The Hawkesbury estuary
Upper reaches of Berowra Creek, a hop skip and jump from the Hornsby Westfield

This is our backyard, encircled by the salty embrace of the Hawkesbury estuary.  But it doesn’t end here, with the secretive topography of flooded river valleys. All the way up (and down) the New South Wales coast, the shoreline is flanked by coastal lagoons. I’m not complaining, even the tiniest little bit, about all these sheltered waters.  But I’ve started to wonder what geographic accident has given a timid canoeist so much to feel grateful for.

Along with marshes and flats, coastal lagoons make up maybe 10% of the world’s seaboards, and in NSW lots of us live by them, many more than by the ocean itself. Lagoons (or wave-dominated estuaries – there are ongoing hissy-fits around these definitions) appear where low-lying plains, rather than dramatic cliffs, meet a shallow gently sloping seabed.  Usually, they are found on shores shaped mainly by waves rather than big tides, with underlying rock that crumbles nicely into beach sand not finer, silty sediment.

The more sand the better – perhaps our generous continental shelf harbours this bounty from a time when the Sydney Basin was a enormous braided river delta, like the Ganges today.  But you don’t want too much rain – lagoons are usually fed by an underwhelming little creek or even just groundwater – that doesn’t (or doesn’t often) burst through the land between waterway and ocean.

Dawn breaks over the barrier between Bombah Broadwater and the open sea

To make a lagoon*, you need a barrier to the open sea.  In the nineteenth and first part of the twentieth century, coastal geomorphologists duked it out over just how these barriers were born.  Did breaking waves make for ever-rising off-shore sand bars?  Did encroaching seas submerge coastal dunes? And then there’s the third, attractively named “spit accretion theory” (Davis and Fitzgerald, 2004).  Not, as it might sound, a creation myth where bunyips drool into puddles between the dunes; just sand clinging to rocky headlands as it is carried along the coast by the (delightfully piratical) longshore drift.

It turns out that everyone was right, at least some of the time.  Which is nice.  It’s hard to keep the heat in a scientific controversy when lots of the evidence, hidden beneath the surface of the sea in the first place, has been washed away or covered over during the last few millenia by terrestrial silt or aeolian sand.  Who could be angry with such mellifluous and frankly otherworldly-sounding geomorphologies in play?

Pelican landing on Bombah Broadwater

Most lagoons have only been around for a little while, geologically speaking, formed after sea levels began to rise as glaciers melted 18,000 years ago or thereabouts. Many, like Narrabeen Lake, which we whizzed round on our bikes in the company of half the population of the North Beaches a few weeks ago, are even younger, not seven thousand years old. A blink of the eye for people who were here 50,000 years before.

Strangely, lagoons move.  Today’s surfers walk across the relics of yesterday’s drowned lakes.  Barrier beaches migrated landward, emerging from the ocean just as “marine transgressions” (that’s advancing oceans, not the naughtiness of waves) slowed.  Shaped in stable times, coastal lakes still don’t hang around for long.  This shouldn’t surprise me – I know that, despite appearances, beaches are really rivers of sand.
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If the tides were higher, if the rivers was faster or siltier, if Australia wasn’t so seismically serene, the lagoons would fill up and dry out or be washed away, and the cormorants would have to hunt elsewhere.  In fact, for all our dredging and draining, it’s happening right now.  Like life itself, coastal lagoons are a transitory phenomenon, a passing pleasure.
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Surfers floating over the relics of yesterday’s lagoon
Narrabeen Lake
Black swans in Narrabeen Lagoon
(Little?) Black cormorants
Intermediate egret in Narrabeen Lagoon
But sometimes, under the fresh sand and brackish water there are older and odder things. The beautiful Myall Lakes, where we not long ago spent a glorious weekend, lie in the bed of an ancient river, separated from the sea not just by dunes that arrived ten minutes ago (okay, 2,000 years ago) but also by the Inner Barrier, deposited before the last glacial maximum and thirty times older.
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And then there’s the gyttja, something so very special it’s found nowhere else in Australia, and helps qualify Myall Lakes as a unique protected wetland.  What is it?  Well, rotting pondweed.  No, I’m underselling it: it’s up to 70cm of  “a highly mobile and organic mud that has a gelatinous appearance”, a “flocculent green–brown material” (Drew et al 2008), “an uncompacted, anoxic and sulphurous ‘ooze'” made from “the decomposition of charophytes, macrophytes, cyanobacteria and algae”.  Strangely, not so much about the ooze in the National Parks brochures.  But it’s an ooze that’s been there for, perhaps, a thousand years.
Dusk on Bombah Broadwater
Looking west at dawn on Bombah Broadwater
Canoeists in the gloaming
Eric the Egret on the Bombah Point Ferry
Glorious Angophora
Reflections on the tea-brown waters of Myall Lakes
Still morning on Two Mile Lake

I’ve been thinking about lies beneath the surface of the water and the windblown sand.   But paddling through the Broadwater two weeks back, in a startling moment I found myself not gliding above the mysteries of quiet waterways, but surrounded, right amongst it.  A huge flock, a murmuration almost, of little black cormorants, perhaps returning from a fishing trip, passed above and on one side and on the other without a single cry but with a sound I’ve never heard before: the white noise of hundreds and hundreds of moving wings.

The sound of the midwinter lagoon, all around me.

Little black cormorants murmurating

* Be warned: there’s a chance my account of the origins of coastal lagoons is completely wrong.  After all, the New South Wales coast “has provoked many questions and various degrees of controversy” (Thom, 2010, 1238).  And perhaps it’s “premature to attempt a comprehensive analysis of coastal lagoon evolution and dynamics when so many lagoons have been so little studied” (Bird, 1994, 13). In case you want to check my workings:
References
  • Bird, Erik (1994) “Physically setting and geomorphology of Coastal lagoons”  in Kjerfve, B. (ed) Coastal Lagoon Processes, Elsevier
  • Davis, R. and Fitzgerald, D. (2004) Beaches and Coasts, Blackwell Science
  • Drew, Simon Iona Flett, Joanne Wilson,Henk Heijnis, C. Gregory Skilbeck (2008) “The trophic history Myall Lakes, NSW, Australia”  Hydrobiologia 608
  • Eyre, Bradley and Damien Maher “Structure and Function of warm temperate east Australian lagoons: implications for natural and anthropogenic changes” Coastal Lagoons: Critical Habitats of Environmental Change, dited by Michael J. Kennish, Hans W. Paerl
  •  Martin, Louis and Jose Maria Landim Dominguez (1994) “Geological history of coastal lagoons” Kjerfve, B. (ed) Coastal Lagoon Processes, Elsevier
  • Masselink, Gerhard and Hughes, Michael (2003) Introduction to Coastal processes and geomorphology, New York, Oxford University Press
  • Thom, Bruce, Hesp, Patrick, Bryant, Edward (1994) “Last glacial ‘coastal’ dunes in Eastern Australia and implications for landscape stability during the Last Glacial Maximum” Palaeogeography, Palaeoclimatology, Palaeoecology 111 (3-4)
  • Thom, Bruce (2010) “New South Wales” Eric Bird (ed) Encyclopaedia of the World’s Coastal Landforms, Springer