Fly in, fly out

The first asparagus is up.  The greenflies are sucking the life out of the few broad beans plants that survived the gnashers of the garden’s winter visitors.  The bowerbirds are brutalising the new growth on the liquidambar, in a jaunty colourised style that makes me think we have a flock of Calamity Janes in the canopy.  Spring is here!

But what about the spring birds?  I haven’t heard the first koel of the season, but the channel billed cuckoos have squawked their way into our dreams.  And in the last week, a new rolling trill in the trees: the olive backed orioles have returned.  We rarely see them around here, but according to Michael Moorcroft’s “Birds of Australia” as “common”.  The emergent twitcher in me sighs.

I met a charming French skin specialist once, and asked her why she moved to Sydney.  “We have melanoma in France of course” she said “But really, if you are interested in skin cancer, Australia is the place to be”.

On the other hand, if you long for the sight of that first feathered visitor arriving from a epic transcontinental journey, you’re better off in the Northern hemisphere.  All the ocean in the southern half of the globe, moderating seasonal temperatures; barriers of forest and ocean; a less icy past; uncertain rainfall and an often arid climate; and (somewhat unconvincingly) weirdly, lots of  “V” shaped continents; all reasons I’ve come across to explain why we have so few migrating birds around here (Someille et al 2013; Dingle 2008).

Back home, two thirds of my French oncologist’s local birdlife would be part time residents.  But in Sydney, it’s maybe one in five.  In the outback there are nomads, roaming around trying to find things to eat in an arid landscape, but there are hardly any regular migrants at all.

silver-eye-chestnut-4-crop-larger

Tasmanian silvereye mid-migration, Zosterops lateralis lateralis

What we do have lots of in Australia are “partial migrants”.  Somewhere between a third and a half of bird species have some sedentary individuals while others take off in the colder weather (Chan, 2001).  Most silvereyes, for instance, stay put, but many Tassie birds – chunky numbers with chestnut sides, like the one above – fly across the Bass Strait in winter, possibly island-hopping as they make their way to Victoria, NSW and Queensland.  On my way to work the other day, I was was befuddled by the strange appearance of a crew of migrants – on their way home, perhaps – milling around happily in the company a bunch of plain-brand silvereyes.

Hard working bird lovers have been tagging silvereyes for 30 years (Chan, 2001), so we know what these guys are up to.  But in general, partial migrants are tricky customers – figuring which of the identical birds you see are interstate visitor and which are locals is mostly pretty hard to do.

After reading a bit about research on bird internal navigation systems, I’m starting to think this kind of deviousness may be payback.

One set of experiments involved keeping captive birds and observing what corner of their cage they batter themselves against, driven by migration-restlessness or Zugunruhe (one of those cool German words for which there is no English equivalent).  Researchers messed with the heads of these captive birds, using mirrors to shift the apparent direction of the sun so they could see what new quadrant of their cage they try to escape through.  Other experiments placed caged birds inside a magnetic coil to warp their sense of direction – a research activity truly worth of evil genius from X-Men. Although I do find the thought of a bunch of 1940s songbirds flooding into a planetarium – another early experiment – quite charming (Burton 1992).

 

dawn-moon-best-tight-crop

If you do see a trans-continental migrant in Australia, it will probably be a shorebird.  About 35 beach loving species migrate here (Dingle, 2008).  On a paddle up Mooney Mooney Creek last weekend, I was really happy to see one of them: an eastern curlew, its absurdly long beak mucky after joyously feasting on the mud-flat crabs off Spectacle Island.  Flying from Siberia will take it out of you. Between the bloody photographers, the houseboats and the jet skiiers, it’s not hard to see why these guys are classed as critically endangered around here.

 

 

References

Burton, Robert (1992) Bird Migration, London: Aurum Press

Chan, Ken (2001) “Partial migration in Australian landbirds: a review” Emu, 2001, 101, 281–292

Dingle, Hugh (2008) “Bird migration in the southern hemisphere:
a review comparing continents” Emu  (108), 341-59

Somveille M, Manica A, Butchart SHM, Rodrigues ASL (2013) Mapping Global Diversity Patterns for Migratory Birds. PLoS ONE 8(8): e70907. doi:10.1371/
journal.pone.0070907

R2D2 in black and white

I’ve been spending a lot of time with magpies lately.  “Model magpies” as my nine year old aptly described these two who spent the day  posing in the Japanese maple and prancing around the back deck.  Oddly enough, the companionship steps up in intensity whenever I stop typing for a snack.

This gang of youngbloods don’t spend all their time begging for food and doing catalogue shoots, though.  There’s also the occasional training session for the Olympic synchronised vogueing competition.

And, of course, plenty of carolling.  The juveniles spent a lot of time last week singing for their supper, until one of the grown-ups got jack of the whole thing and flew down to show them how it was done.

But not before the youngsters did their party trick.  In amongst all the mellifluous warbling, my ear caught some distinct moments of robotic squeaking and clacking. The magpies were doing a bowerbird impression.

Apparently Australian birds are uncommonly good at mimicry.  Lyrebirds are famous for it, but all sorts of implausible suspects have a line in impressions as well: magpies, mistletoe birds, silver eyes. Apparently the minute brown thornbill has been recorded mimicking a pied currawong – a bird forty times its size.

Why do birds mimics the songs of others?  Pretending to be something bigger and tougher for self defense purposes seems to be one motive.  Bowerbirds have been observed doing raven impressions while being mobbed by a colony of those rather nasty bell-miners, for instance.

Another seems to be showing off to make yourself look good to potential mates.  Researchers have found that male bowerbirds that can only manage a one or two rubbish impressions (singing “like a kookaburra with bronchitis”, as the researcher cruelly remarked) have less mating success than those who can effortlessly produce a good five.

The most hilarious explanation I’ve read for bird mimicry is to chill out sexual partners.  Researchers reckon that R2D2 style squeaks and clicks that satin bowerbirds make while courting can freak out their mates:

“by interspersing melodic mimetic laughing kookaburra and Lewin’s honeyeater calls between episodes of harsh mechanical calls, males may calm females and improve the likelihood of that females will stay for additional courtship and copulation” (Borgia and Keaghy, 2015)

The idea that a sudden explosion of kookaburra calls would mellow you out and get you in the mood gives me a good picture of why certain male bowerbirds (and possibly particular male ornithologists) might be unlucky in love.

While not as famous as lyrebirds, bowerbirds do some pretty amazing impressions, not just of individual sounds but of whole acoustic scenes.  How’s this, observed from a toothed bowerbird?

A male started with the sounds of a group of people talking as they moved through the forest with their machetes cutting bushes and dogs barking, and continued with the sounds of machetes being used to fell a tree, complete with the rattle of shaking leaves after each blow and eventually the sound of the tree falling and hitting the ground with a crash (Borgia and Keaghy, 2015, 97)

The humble magpie doesn’t do badly either.  They’ve been recorded copying 21 different species of bird, as well as the sound of horses, dogs, cats and humans.  Magpies, it appears, only imitate critters that share their territory, not just the blow-ins and passers by, so it makes sense that our youngsters copy the satin bowerbirds that seem so spend much of the year in the garden, eviscerating my beans and kiwifruit vines and making free with my broken pegs.

I’ve got a whole new agenda in the backyard now.  There’s those in-flagrante males doing kookaburra impressions to listen out for.  As yet, I haven’t found any references to magpie calls appearing in the satin bowerbird repertoire.  Maybe this will be my contribution to science.  Better still, maybe I’ll catch a bowerbird in the act of ripping off a magpie doing a remix of another bowerbird.  Or the other way round.

Additional references

Borgia, G. and Keaghy, J. (2015) “Cognitively driven cooption and the evolution of sexual displays in bowerbirds”in Irschick, D., Briffa, M and Podos, J. (eds) Animal Signalling and Function: an integrative approach, Wiley Blackwell

Kaplan, Gisela (2015) Bird Minds, CSIRO Publishing

 

A flash of gold and a stash of blue

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Season of mists and mellow tinnies: the Hawkesbury in fall

Autumn lasted for aroundabout a fortnight this year.  The endless summer of an apocalyptic El Nino wrapped up in mid-May, giving the deciduous trees an extremely tight schedule to dispense with their leaves before this weekend’s torrential rain.

We’ve had autumnal glory in the kitchen as well.  When Keats talked about the “season of mists and mellow fruitfulness”, I’m not sure he was thinking about bananas.  In theory our crop of tiny fragrant fruits should have been perfect for lunchboxes, but I made the mistake of describing the first-ripened one as “Geoffrey”.   After this, not only Geoffrey but all his brothers were deemed “too cute” to be eaten.

As well as the gold in the fruitbowl, there’s been plenty of gold in the trees.  The yellow-tailed black cockatoos are back in force, mewling and crunching in the radiata pines.

Yellow tail and autumn leaves horizontal

Fly by from a yellow tailed black cockatoo

And for the first time this year, I’ve noticed the migrating yellow-faced honeyeaters.  Thousands of them pass through the Blue Mountains most autumns, it seems, but this year they’ve been funnelled between the mountains and the coast, through the Hunter Valley.  I first spotted them darting through the riverside casuarinas at Karuah National Park, on our trip north, but since we’ve been back, I’ve seen flocks of them with their travelling companions, the noisy friarbirds, pouring up the Hawkesbury.  I’ve even seen them on the way to work, taking a moment out on their journey to watch the commuters boarding the morning train at Berowra Station.

But not all the autumnal excitement has been touched with gold.  Last weekend, halfway through detaining my broad beans (fencing, netting and a mulch of lavender and liquidambar – doubtless all in vain) I spotted a little collation of royal blue underneath the pomegranate tree. Nerf gun ammunition, the lid of a milk container, a peg.  Signs that we need to tidy up the yard, and a hint that randy bowerbirds might just do it for us.

 

More autumnal reflections from our backyard:

Let them eat light!

Autumn in terminal decline?

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Backyard gold

The silver river

Deerubbin – the Hawkesbury proper- doesn’t normally look like this: not when I’m there, anyway.  I’m used to the view out our back window: the valley full of fog, the hilltops islands in a foamy sea.

Hazy foggy view from deck

Mist over Sam’s Creek

You know the fog will be spilling across the highway as you swoop down from the ridgeline before dawn.  But when you reach the freeway bridge that stretches half a mile across the  Hawkesbury, the wind picks up and the mist is gone.

But not this Sunday.  The cloud was down and the river was silver.

Pixillated tinnie in distance

Fisherman in the mist

I’ve wrestled with this mist before.

I can say with confidence it’s not freezing fog, hail fog or upslope fog.  For all the salt in the air, it’s not coastal fog – moisture condensing over cool water – not with sea temps a balmy 24 degrees.  And is it valley fog? Damp cool air might slide down the hills in the night… but Sunday’s haze followed midnight downpours not clear skies.

Having thought about it rationally and analytically, I can only conclude that this was magical fog, sent to stop me paddling all way to the secret heart of this part of the Hawkesbury, Marramarra Creek.

Mist over over mangrove saplings for horizontal shorter

Big Bay

I’ve nearly made it there before, as far as Big Bay, with its great lagoon full of mangroves and the riverbed chocabloc with critters. No houses on the ridgelines, no way in except by water.  In the 1830s a surveyor’s wife didn’t think much of it: “these dreary solitudes might serve for the abode of a misanthrope so utterly are they secluded from all approach and so entirely destitute of all comfort”.  But I’m longing to paddle all the way to the source of the creek, through country with an indigenous past even I can read.

But this time it wasn’t just the fog and the march of time that stopped me.  The birds were in on it too, perching photogenically on the wayside oyster poles, feathery sirens luring me away from my upriver odyssey.

So I’ll have to come back to Marramarra.  Maybe next time I’ll bring our full flotilla of mismatched craft and camping gear and stay overnight halfway up the creek in the old orange orchard.  The noisy kids should to  scare away the temptations of the sirens… and, of course, the silvery silence.   So perhaps I’ll follow Odysseus and bring some ear plugs too!

Related posts – other paddles on the Hawkesbury from Deerubbin Reserve

Two sad islands, three whistling kites: a paddle from Deerubbin to Bar Island

Of gods and mapreaders: a trip up Kimmerikong Creek in Muogamarra National Park

A bridge fetishist paddles to Brooklyn: paddles up Mullet Creek and around Dangar Island

Broken Bay at low ebb: a short jaunt around the oyster beds near Spectacle Island at the end of Mooney Mooney Creek.

Thinking like a bird

One of the things I love about my regular walk to the the train station is the chance to check out the critters’ daily routines while I’m in the midst of mine.  I’m an everyday intruder, just passing through.  Through the carpark behind the panel beaters’ shed where the glossy black cockatoos do their acrobatics.   Over the slimy patch on the footpath that used to lure eastern waterdragons out to play chicken in the traffic (I stress “used to”. Sad face). Past the carefully tended brush turkey mound in the scrub by the library and round the the blind corner where butcherbirds find their roadkill.  So far I’ve never seen them pecking at the flattened remains of kids on skateboards but I worry.

I was trudging home a few months ago, when there was a kerfuffle in the shrubbery that even the most self-absorbed commuter couldn’t ignore. An aggravated bird was repeatedly hurling herself at an invisible enemy, and making a tremendous din.  I spotted a tail sliding behind the trunk of a halfway up a tree – was it a goanna? a snake?  No, a brush-tailed possum, having a late afternoon snack in a grey butcherbird’s nest. Mum was willing to fight for her eggs to her last breath.  I don’t have any pictures of the stramash, unfortunately, despite roaming around Berowra most days like some bumbling stalker, a chunky camera swinging around my neck.

However, I feel a bit less sheepish about my amateur-hour suburban birdwatching – and a little less clueless about butcherbirds – after  reading Gisela Kaplan’s fascinating book Bird Minds (CSIRO, 2015) this week.

Butcherbird in near silhouette crop

Grey butcherbird makes a rare appearance in the backyard

Bird Minds considers most aspects of avian cognition – social learning, mimicry, tool use, play, abstract thought and emotion  – with a particular focus on the locals.  This, as Kaplan points out, is no mean feat.  Aussie natives are under-discussed in the world of scholarly ornithology, it seems.  She tells (with secret delight, I reckon) how the international community were forced to reluctantly accept that songbirds evolved in the part of Gondwanaland that came to be Australia, overturning 200 years of northern hemisphere prejudice.  The oldest songbird fossil ever found came from here, and recently the discovery of heron footprints from the Cretaceous Era in southern Victoria showed that birds and those other, non-avian dinosaurs cohabited this part of the world, at least, for millions of years.

So, as well as summarising the work of researchers from around the globe, to fill the gap in the published research on Australian natives, Kaplan draws on anecdotes from bird watchers (like the amazing tales of fire-starting black kites that have done the rounds in the papers lately) and her own experience of studying, observing and hand-rearing birds over the decades.  My particular favourite is her story of the adopted 75 year old galah who liked to summon all four household dogs by name in a passable impression of Kaplan’s voice just for the fun of bossing them around.  Every week.  It’s this kind of jolly jape that keeps a bird young.

Galahs in the rain crop

Pair of galahs

Butcherbirds are just the type of birds that Kaplan is interested in, although her own research for the last 25 years has been on another member of the Artamidae family, the Australian magpie.  Currawongs, butcherbirds and magpies, like many other Australian natives, don’t fit a northern hemisphere perspective on avian lives.  Grey butcherbirds are wonderful mellifluous singers, for example (though their tunes are less feted than the improvisational outpourings of the pied butcherbird).  But their carolling doesn’t fit the familiar songbird story.

Kaplan points out, for instance, that while northern hemisphere songbirds are most vocal during the breeding season, the Australian bush is often quietest at that time.  Amongst the much studied birds of high latitudes, males sing as part of a courting display.  In comparison, she observes, “Australian species often seem rather ‘egalitarian’ “.  For many Aussie birds, including butcherbirds “there is often no difference in the song between male and female, no marked difference in plumage or size, brooding and feeding of youngsters and defence” (Kaplan 2015 114).  I have to confess, this whole line of argument really appeals to me.

Magpie with fluff horizontal smaller

Magpie in spring

I also get sneaky pleasure at Kaplan’s observations about the cleverness of Australian birds.  Smarts, she suggests, are one strategy for coping with harsh environments and unreliable climatic conditions.  The humble budgie, a desert dweller, for instance, has one of the largest bird brains for its size, along with Cape York’s palm cockatoo, a formidable tool user.  These clever cockies select, shape and stash particularly excellent sticks, some to use as percussion instruments and others to improve nest-hole drainage.  Behavioural flexibility is a sign of sophisticated thinking: I guess musician cum plumber fits that bill quite nicely.  Birds like this, Kaplan thinks, playful, inquisitive and social, fill the ecological niche of monkeys in an Antipodean environment.

Australian birds often live much longer lives than their northern hemisphere equivalents. Permanent pair bonding means that galahs, for instance, or sulphur crested cockatoos may end up in a 60 year partnership.  Kaplan suggests that these long-term pairings require social nous and a sophisticated communication repertoire.  Forget relationship counselling, it could be time to take advice from the local cockies!

Young Australian birds are also likely to spend a long time hanging around with their parents learning the ropes – an extra year for grey butcherbirds, as much as four for white-winged choughs. Which explains the whiny teenagers I’ve been hearing everywhere lately.

It’s hilarious watching great hulking juvenile wattlebirds, indistinguishable from adults to my untrained eye, sitting in the Japanese maple tree out back, calling plaintively and endlessly for parental attention until someone hops up and gives them a lerp.  And last week on the way home, as I passed Butcherbird Corner, I heard the sounds of a youngster calling out that all-too-familiar refrain: “Mum! Mum! Mum! Mum! Mum! Mum!”.  It drives me mad when my kids do it, but on this occasion, pester-power put a smile on my face.  The lumbering youngster was a survivor of the Possum Bloodbath of 2015, demanding quality time (and a take-away) from its weary parent.

The youngbloods may hang around with mum and dad for ages, but they do get off the couch and help with the housework.  Raising your chicks with the help of older siblings and even unrelated adults – “cooperative breeding” – is surprisingly common in Australia, in comparison to elsewhere. If refraining from tearing your life-partner limb from limb with your own beak during the course of 60 years together is a challenge to a bird’s emotional control, how much more so is long-term living with the extended family?

This is an idea that Kaplan toys with throughout the book – that “negotiated living” might  “require… changes in powers of perception: a watchful eye, powers of observation and careful scrutiny of others… watching others means awareness of others and such habits can change from behaviour reading into mind reading” (Kaplan 2015 122).  Complex social lives go along with complex minds.

I rather enjoyed the sly dig at northern hemisphere birds (they sound nice, but could well be dim) that runs alongside Kaplan’s argument for the evolutionary value of cooperation.

in the competitive mode, learning (in males) is for a well-rehearsed performance: an Eistedfodd of dance or song. In the cooperative model, learning is for communication (Kaplan 2015 119)

Old leftie that I am, I can’t help liking the idea that cooperation, “egalitarianism” of the sexes and general smarts go along together.

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Long billed corellas giving me a funny look

I can’t vouch for the rigor of Kaplan’s science, but I loved reading her stories of the cleverness of Australian birds – their “versatility, resourcefulness, complex social and individual problem solving abilities” (Kaplan, 2015, 193).  Reading Bird Minds has given me plenty to look out for as I make my workaday way through the suburban territory we share.

Old hands

I know I live on, walk on, paddle through, someone else’s country.  Guringgai country, and sometimes Darug lands, since Berowra Creek, or so I read, is a boundary line between people of the coast and river people. Sometimes, I venture north of the Hawkesbury – Deerubbin – into Darkinjung country.  I try hard to remember that I’m an uninvited guest in this land, and that I know next to nothing about it.  Because it’s important to know what you don’t know, if you know what I mean.

But sometimes what you don’t know jumps out and smacks you in the eye.  It happened out on the water, on Smith’s Creek, a couple of weeks ago.

Smith.  It’s a joke name, isn’t it?  The sort of name you use to check into a hotel for a dirty weekend with a person who isn’t the one you’re married to.  A name white guys use to be anonymous.  “Yes, I’m John Smith and so is my wife”.

I’m sure Smith’s Creek is named after a really very important Smith.  After all, at one time at the turn of the twentieth century, Kuring-gai Chase – specifically the bit of bushland between Smith’s Creek and Cowan Creek – was considered a possible location for the capital of the new Commonwealth. Magnificent scenery and handy for getting back to Sydney, what?  You have to wonder whether the sandstone escarpments of Kuring-gai National Park would have been quite such an amenable environment for roundabouts as Canberra. All in all, I’m very glad it didn’t happen. Aside from everything else, I don’t think I could handle a close encounter with Cory Barnardi at the crack of dawn on a Saturday morning.

So, as I say, there I was in “Smith’s” Creek, blessedly free of conservative crusaders and, indeed, showing little sign of human life at all.  In Apple Tree and Stingray Bay, the power boats were moored silently in rows like roosting birds.  Nothing stirred.

As I slipped with the tide towards Deerubbin, not a jetboat in sight, a wave of love passed over me for the sport of rugby.  More specifically, a feeling of warmth for the thrilling final of the 2015 Rugby World Cup, broadcast to the sports fans of Australia at 2am the night before.  What a fine influence sport is on the nation!  How it improves the tone of the place!  All those worn out rugby fans, tucked up in their beds, or snuggled down in their bunks, dreaming of triumph or of despair, but more to the point, not, as yet, starting up outboard motors.

While the rugby fans were sleeping I paddled, more or less, back to Berowra, swaddled in fog that rolled down the valleys, smudging the pictures of my weekly sea eagle (curse it).  They slumbered on as I turned the corner into Smith’s Creek following the great big signs on the shoreline, papped some peeved looking cormorants, tried and failed to see any sign of rays in the sands of Stingray Bay.  In the stillness, I felt as if I was in a dream myself as I passed along sandstone cliffwalls, rippled and rainbowed, that slide down and down into the bottle green water, and beneath the smooth-barked gums that butt their way into solid rock a metre or two above a tideline line of oystershells.

The sports lovers were still sleeping when I had my magic moment – the one you wait for every trip – when moon and raptor met in the bright morning light.  So for all their shiny cruisers and thrumming engines, the rugby fans would have been no good to me at all if Egg the ancient kayak had drifted away, as it very nearly did, while I tried to find that damn whistling kite in what seems, through a zoom lens, like a very very big sky.  That would have been me, stranded in sparkling knee-deep water, with a ten k swim through the bobbing jellyfish, all the way home.

It wasn’t until I got back and uploaded my photos that I saw, in the corner of a picture, the ochre hand prints on the golden rock.  Who put them there and when?  I really don’t know.  Maybe someone not so long ago – the indigenous rangers of Guringgai take loads of school kids out to see the hundreds of carvings and paintings that are all over the park.  I bet a bit of print making happens here and there.  Could it be one of the people of West Head slain by smallpox – no accident it seems – just a few years after the convicts arrived? Surely not.  Someone in the time in-between, making their mark on country.  Still here, though many people were forced far away, as far as Yorta Yorta country, on the borders of Victoria.

I just don’t know.  Those hands told me, at least, to remember that I don’t.

Encounters with eagles

May I present this week’s sea eagle?

As yet on my estuarine adventures, I haven’t seen a score of sea-eagles on a single morning (although I can imagine a battalion of them, flying in formation), but an encounter with an eagle has become as much a regular feature of my kayaking expeditions as the ubiquitous white-faced heron. Those cryptic little passerines in the riverside scrub are hard to spot even if you’re not short sighted and half deaf.  So three cheers for the white-bellied sea eagle “large and conspicuous” “easily sighted when… soaring… in search of prey“.  Haliaeetus leucogaster, you are the middle aged canoeist’s friend.

There was the eagle we saw battling it out with a pair of whistling kites over fishing rights on a fabulous family excursion across the Hawkesbury from Brooklyn, across the surf-line and up the Patonga River.  According to Wikipedia, sea eagles harass smaller raptors like kites in hopes of stealing their prey.  Not today, Josephine.  This eagle was bested by the lowly kite, unwilling to relinquish a top notch fishing spot.  I need to listen to my own advice to my students – don’t believe Wikipedia!

An eagle even made a guest appearance on a modest little paddle down the end of our street.  This was one mellow raptor, its apparent indifference to poorly coordinated amateur photographers splashing around trying to get a good shot belying its rep as a “shy and easily disturbed species“.  Ruth, my companion on the water that day, had seen a sea eagle, earlier, on the very same bare branch, while bushwalking along the ridge above. Same bird or just a popular perch?

Since the rule for my stolen Saturday morning paddles is no more than half an hour in the car, I’ve frequently had this very thought as I spot yet another sea eagle.  Same bird?  Am I being stalked by just one glorious if persistent raptor who’s somehow taken a fancy to my little craft, charmed perhaps by its avian-friendly name?  Or is the Hawkesbury awash with sea eagles?

Even the Department of Environment in its definitive run down on Haliaeetus leucogaster doesn’t seem super sure. Their guesstimate of 500 pairs across the whole country is based on a one for every 40 kilometre of Australian coastline would pretty much mean that all the eagles in my photos are the same dude (or dudette – the females are larger but I find it’s kind of hard to tell if a bird is small or if it’s just far away).

Either way, I’m 100% sure this week’s eagle is a new one, since I saw it at the start of a paddle down Wallarah Creek, seventy ks north of here.  The creek wends its quiet way through bushland past the Wyong North sewage treatment plant to Budgewoi Lake.  What with my burgeoning interest in taking blurry pictures of distant bird-life, it seems I will be spending more and more time hanging around sewage farms – they seem to be the go-to venue for the would-be twitcher.

The Budgewoi eagles seem a bit more coy than the Berowra locals, as you can tell from this dodgy pic on my maxed out zoom.  Or maybe it’s just that this sea-eagle didn’t want to share her supersized snack.

Which, after observing the consequences of fraternisation with humans for other birds I saw on my way up Wallarah Creek, is probably a good thing.

Up until recently, it was thought that carelessly discarded bait, hooks and line were the big killers of waterbirds, and there have been some efforts made to make sure fisherfolk dispose of their scraps in the rubbish rather than leaving them lying around – not such a big ask really.  Some have even argued for the use of biodegradable line and hooks that will rust away (eventually).

But efforts to get fishermen to clean up their act have had surprisingly little impact on the number of waterbirds being injured or killed by fishing tackle.   In fact, research by academics and wildlife rescue organisations in South Australia and New South Wales suggest that the vast majority of birds that get entangled or hooked – often pelicans, but also plovers, gulls and stilts – get caught up when they are close to people actually fishing.

After my trip up Wallarah Creek I can see why.  As I passed riverfront houses with their landing slips and jetties I saw pelicans lounging on back lawns and an excited egret being thrown small fry by a local.  Even the striated heron, normally shy, flew off in the direction of human habitation, not the other way.  The birds around here are familiar with humans, their tinnies, their by-catch and, unfortunately, their fishing lines.

Nine herons hunting

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….

… three posing pelicans

… two eagles soaring

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

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?

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.

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?

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

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

Russet trees & scarlet tails

Is that fall colour I see on the hillside as the mist parts over Calabash Bay?  Nope, wrong season, wrong continent.  It’s the golden-brown tips of the casuarina trees, the males that is, laden with pollen and catching the morning light.

For all their evocative latin label – named after their cassowary-like foliage – the casuarinas are a mournful kind of tree, I think.  The wind whistling through the wispy branchlets of the she-oaks takes me straight back to solitary times in childhood.  Even Wikipedia notes, rather poetically, how quiet it is in a she-oak forest, sound muffled by the blanket of fallen “needles”, in an understory where other things refuse to grow.

Not so quiet this morning, though.  Just as I was cursing my missed train, there was a “kraaaaak!” and a flash of red in the trees between the commuter car park and the RSL.  New guys in town (or new to me anyway): glossy black-cockatoos.

Two young fellas and an older female, I reckon – a typical little group for these birds, it seems, unlike the yellow and red tailed black-cockatoos that stay in bigger flocks.  The two lads flapped from tree to tree, red tails glowing in the sun, while mum (or cocky-cougar?) chilled out next to Berowra Car Care, having a good old preen.

Glossy black-cockatoos are fussy eaters.  The penny has dropped for yellow-tails that they need to diversify their eating habits and these days they’re doing okay, thanks to pine trees like the great big decrepit ones in our yard.  But these birds really only like the woody fruits of the allocasuarinas  – and turn their noses up at even some of those.  The black she-oak, casuarina littoralis, is a particular favourite and, now I’ve started to notice them in their winter finery, it seems there’s plenty of them around here.

But the black oaks don’t come back too well from big, hot fires.  And the glossy black cockies are competing with galahs, corellas, sulphur cresteds and mynahs – birds that don’t mind land being cleared and subdivided.  Humans knock down the big old trees, feral bees nick the nesting hollows and possums steal black-cockatoo eggs.  Perhaps it’s not surprising I haven’t seen these lovely birds before.

Or maybe they’ve been here all along, “inconspicuous and cryptic”, leaving a trail of half-chewed casuarina orts, just a red flash in the golden silence of the she-oak trees.

Rest day on the Tour de Hawkesbury

Plunging down the switchbacks of Berowra Waters Road with a canoe strapped on top as a weekend dawn breaks is a hair raising experience, for a newbie driver like me anyway.  At any moment, heavy breathing MAMILs (Middle Aged Males In Lycra according to our friend Bruce Ashley, author of Bike It! Sydney and Cycling around Canberra) might suddenly loom out of the fog in the middle of the not-quite-two-lane road.

They’ve swooped down through Galston Gorge, across the only bridge, passed swiftly through Arcadian horsey country, and after a moment of quietly gazing out at the marina as they cross the ferry, they’re battling the steep 200 metres ascent up to the ridge.  It would seem rather cruel if, after all that effort, my kayak shot off the roof in an emergency stop and impaled them before they got that well-earned coffee.

Scary as this drive is, it’s not quite as nerveracking as coming back from the Hawkesbury up the Old Pacific Highway on a misty morning – a journey that is begging to be made into a terrifying but addictive computer game called something like “Drive of Doom” or “Death Dodgems”.

Peering through the billowing mist round the hairpin bends, you hope you’ll spot the scattered packs of labouring MAMILs in time to slide right, all the while praying that a mob of motorbikes doesn’t choose that moment to come roaring up from behind to wipe themselves out on your rear window.  Or that an oncoming vehicle doesn’t take the next tight corner wide and smash into you headlong.  The reward if you win a game is obvious: a triumphant stop high above the clouds at “Pie in the Sky“, a place where the lambs lie down with the lions, or at least, the road cyclists eat pies with the bikies.

But not this weekend.  Not a single specimen of the MAMIL, keystone species in our local ecosystem, to be seen.  What’s going on around here?

Eventually, as I hauled the kayak off the car and wrestled it into the water, I worked it out.  The MAMILs have been up all night watching the Tour de France.  At two o’clock in the morning they were gripped as Mark “The Manx Missile” Cavendish floated past Andre “The Gorilla” Greipel to claim his first stage win in two years, his twenty sixth stage in the Tour.  And they’re still curled up in bed, knees bent under the covers, dreaming they’re Australia’s next Cadell Evans.  Middle aged, but still contenders.

The river was very very quiet too.  In February this year, I ventured for the first time into the brackish winding creeks that feed Calabash Bay.  It was fish paradise.  Despite my complete indifference to fish as a meal, pet or leisure pursuit, the sheer numbers of tiny transparent spratlings leaping from the water and darting between the mangrove roots was eye opening.

Even nearly twenty years ago, just after the high point of algae blooms and floating maritime corpses in Berowra Creek, research into estuary processes discovered twenty nine species of fish up and down the water.  Marra Marra Creek, in the lower reaches, with its saltmarshes and long stretch of mangroves, was the richest, but even upstream there were flathead and flounder, gobies and mullet and perchlets, silver biddies and pacific blue eye.

But this weekend, nothing.  I went to see the fish and it was out.

One azure kingfisher was so weak with hunger it sat exhausted on a waterside twig in full view long enough for me to take a numerous terrible blurry photographs.  If I keep going out in these lean times, I may finally get the chance to take a sharp, closeup shot of an emaciated glinting blue bird spiralling slowly downriver on its back.

Despite my glass-half-empty-and-probably-tainted-with-nuclear-fallout tendencies, I’m pretty sure the lack of visible fish is a natural thing, part of the cycle of life.  Most of the inhabitants of the creek spawn in spring and summer, so the tiddlers of the summertime shallows are no doubt happily traversing deeper waters now, invisible and unknowable to those who drift involuntarily into unconsciousness at the mere mention of rod, bait or tackle.

There must have been a few fish around, I guess, along with the amphipods, the isopods, the molluscs and the worms. I saw a few blokes slumped gloomily in tinnies, a handful of great cormorants and the contractual obligation pair of white faced heron in every cove and mudflat.

My ship building neighbour rates his sequence of ancient clapped out Mercedes according to the number of cows featured in the interior trim (“a two cow Merc”, “a four cow Merc” etc).  I’m thinking I should start rating my canoeing trips similarly, according to the number of white-faced herons I see during the day.  This Saturday was, by my calculation, at least a nine-heron day, and that’s not giving myself extra points for seeing the birds in pairs, hedgehog like in their full breeding regalia.

But all in all, there still plenty of solitude to be found out there in the mist.  I’m not sure, but I may have discovered a new form of white-water canoeing.  It may not be high-octane, but it’s got to be higher energy than watching Gabriel Gate on late night TV.  I think I like it.