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

 

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.

Long beaked corellas giving me a funny look long.jpg

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.

Nude trees and naughty birds

Who lives in our backyard?  How would I know? I haven’t been paying attention.

I see a flash of black and white down by the chook run and what do I think?  “Magpie”.  Humans, huh?

Yesterday, ominous thumps and crashes below the lightning-riven radiata pine had me racing to see if it had finally succumbed to a pincer movement of termites and southerlies.  But no, the demolition job was courtesy of a pied currawong, ripping the tree apart like it was a lego construction.  Well, a lego construction with integral insects.  Since in the (distant) future Lego will apparently be “sustainable”, one day this might even be a thing.

Perhaps it’s for the best that Lego’s green-washing target date is a decent decade and a half away.  Depending on how significant bark is to the structural rigidity of defunct pine trees we might need to use those infestation-proof plastic bricks – we’ve got enough of them under furniture and half buried in the garden – to rebuild our crushed house.

That’s if the currawongs are here to stay – and they might be.  Back in the day, before the ’40s, currawongs came down from the mountains to visit Sydney over the winter, but now they hang out in the big smoke all year round.  They like it down here, snacking on cute little birds and munching up the tasty berries of our attractive invasive plants.   If I want to save the roof, that monster privet the size of a redwood may have to go.

And a sighting today of another naughty black bird has cast doubt on the long-settled verdict in the Case of the Phantom Egg-Eater.

There was a stramash this morning between a crowd of brush turkeys and an crow, the latter carrying something that from a distance might appear to resembled a chicken’s egg.  I have no pictures of the actual incident but only an image extracted from the raven’s dream, in which hens’ eggs are light as a feather and easily borne in the beak for leisurely later consumption in convenient locations.

Later investigations showed that a freshly laid chook egg had indeed be devoured, but, in addition, one of the fake plastic eggs, carefully placed in the nest with to confuse and baffle hungry brush turkeys, had also vanished.

I’m not sure what this tells you about corvid intelligence but to me it suggests that ravens are optimists.  Apparently young European ravens are extremely curious.  In experiments where juvenile birds were offered “novel inedible items”, it seems, “birds never missed any potentially edible item … even with “highly cryptic objects”.”  I think it would be fair to call last year’s Easter hunt left-overs “highly cryptic objects”.  Maybe this was a young ‘un because apparently adult ravens are “neophobic”.  I’m assuming this doesn’t mean harbouring a hatred for Keanu Reeves in the Matrix sequels (though this is not an unreasonable viewpoint), but rather preferring actual foodstuffs to eccentric plastic replicas.

Where does the arrival of this new mob of razor sharp egg-robbers leave our prospects of our home-grown protein?  I can almost certainly outwit a brush turkey, but the socially adept, tool-using raven with the problem solving skills of a seven year old might give me a run for my money.  Perhaps I should plant some more broad beans.

And there’s more backyard black-feathered bandits where they came from.  The red-eyed, jet-feathered male koels are gone for the season, but the bowerbirds are back – mostly the “greens” – olive, stripey young bloods and females – but every now and then there’s a flash of violet-black as a grown male, glossy and gorgeous, disappears, full bellied, into the shrubbery, after a exhausting afternoon of shredding my kiwifruit vines.

But, despite my doziness, there was no way I could mistake today’s most magical visitor for a common or garden magpie.  Nude trees held no allure for her.  She watched me, still and cautious, from a leafy branch low in the hibiscus, patiently waiting for maybe five long minutes while I snapped away incredulously.

I reckon she came after the noisy miners that have descended on us over the winter, yipping and snapping at the wattle birds.  Last I saw the sparrowhawk, she was gliding off through the jungle at the bottom of the neighbour’s garden, indignant miners in hot pursuit.  I’m hoping she got the best of them.  What a fitting end for those hateful lerp eaters – fastidiously “killed, plucked and eaten”, all the while clutched in a sparrowhawk’s long and elegant middle toe.

I hope she’ll be back.  I’ll be keeping watch.

The secret lives of big bold bug-eating birds

In my fantasy life, my garden is filled with the delicate calls of rare and tiny birds that feed exclusively on cabbage white butterflies, flies and mosquito larvae, and pause in their labours only occasionally (at times of the day with particularly flattering light) to perch photogenically directly opposite my back deck.

My real backyard, however, like the rest of Australian suburbia, is awash with great big, loud, gallus beasties: cockatoos, kookaburras, magpies and of course the damned brush turkeys.  Seems like there’s more of them here in Sydney than ever before.

They may be common as muck, these big bold birds, but they’re not to be sneered at.  They have their own mysteries.  How do breeding magpies meet and pair off?  Why are kookaburras so faithful to their mates? How do cockatoos select whose timber house they’re going to rip to shreds?

To be fair, if the bird-life in suburbia is fairly predictable, bird watchers are pretty bog-standard as well.  I love this comment, in an article marvelling at the speed with which bird atlases are compiled, while more unglamorous animals – favoured by God, perhaps, but not necessarily by citizen scientists – live and die in obscurity.

“Ornithology… was a totally useless subject, the amateur’s field par excellence, largely ignored by even non-utilitarian academics.  No one entered it expecting to be given money and no one, for sure, had ever emerged with any.  Yet… it was here that organised natural history was to accomplish its greatest feats…. its secret lay in numbers.  Birds had a breadth of appeal that no other branch of natural history could rival” (Allen, cited in Adam, 2010, 11)

I’m cultivating LBB habitat and an interest in beetles.  In the meantime, there’s still the challenge of trying to figure out what the “obvious fauna” (Wilks, 2010, 288) are up to in my backyard.

For instance, what’s going on here?

Was there was a stash of sausages in this hollow in the pine tree to put that big smile on this kookaburra’s dial?   If so, they must have been those tiny party saveloys since she kept coming back for more.

Actually, kookaburras don’t subsist entirely on barbecue left-overs or snakes.  Insects make up a big part of their diet, and like magpies, they normally find food on the ground, dropping onto prey from a perch above so they don’t have to do any aerial acrobatics toting that great big kingfisher beak.

Given that birds usually feed in the leaf-litter, or in the sky, or in the canopy – they don’t usually mix it up – I’m not 100% sure this was actually snacking.  Like cockies and magpies, kookaburras are have stable, even “traditional”, territories guarded by the same breeding pair for years and years (Legge, 2010, 48).  And cackling away together isn’t the only way that kookaburra clans – pair-bonded breeding couples and their older offspring “helpers” – mark out their turf.  They also stake their claim with some mid-air show-offery.

Sarah Legge describes one such bit of border policing, a “bellyflop display”: “a single bird flies from a perch to another tree 5-20 metres away in a graceful swoop that ends with a flared landing on the lip of a hollow.  It pauses there momentarily, then swoops back to its original perch”.

Sounds pretty familiar, though I didn’t see a rival posse of bellyfloppers in action today.  Maybe my kookaburra was getting in shape for a big flopping battle down the track.   Or maybe she was really was scarfing saveloys…?  Without photographic evidence, who can say…?

Another of this week’s mysteries: what makes this poor benighted tree the most delicious in the neighbourhood?

After our recent visits by black cockatoos, I wondered if that this scarified specimen might be host to  wood boring larvae that are said to appeal to the yellowtail palate.  I’ve come to suspect that proper ornithologists share the bird watching punter’s lack of interest in bugs, since descriptions of cockatoos’ preferences are ubiquitously vague –  the sites I’ve consulted all comment tersely that yellowtails like “some insects”.  Thanks for the detail, guys.

Mind you, maybe this vagueness is a result of the fact we’re all so “meh” about bugs we can’t even be bothered giving them names.  David Wilks notes, for instance, that a survey of just four types of eucalypts in Western Australia recently identified more than two thousand species, most of them unknown (Wilkes, 2010, 288). I reckon we’re well overdue for a PR campaign to sell us on cute, quirky and cuddly bugs. And there is one!  Manu Saunders is trying to spark up a month long celebration of “Arthropod April” … though thinking about it, we may need “Arthropod August” as well…

If I couldn’t identify the mystery larvae, I had no trouble working out the true culprit in The Mystery of the Tortured Tree:

Is this sulphur crested cockie digging out one of those 2,000 species of unnamed critters?  Does the bark of this specimen have a particularly good mouth-feel, that buttery consistency that just says “bite me“?  Or is this just the local flock‘s agreed upon spot to hang out and have a beak manicure?

Okay, there’s no bird identification challenge here, but I reckon there’s still plenty of secrets to be told in big boofy bird psychology.

References

Adam, Paul (2010) “The study of natural history – a PPP” from Daniel Lunney, Pat Hutchings and Dieter Hochuli (eds) The Natural History of Sydney, Royal Zoological Society of New South Wales

Kaplan, Gisela T. (2004) The Australian Magpie: the biology and behaviour of an unusual songbird, CSIRO Publishing

Legge, Sarah (2004) Kookaburra: King of the Bush, CSIRO Publishing

Recher, Harry F. (2010) “A not so natural history: the vertebrate fauna of Sydney” from Daniel Lunney, Pat Hutchings and Dieter Hochuli (eds) The Natural History of Sydney, Royal Zoological Society of New South Wales

Wilks, David (2010) “A hotbed of biodiversity? A natural history of the Ku-ring-gai council area” from Daniel Lunney, Pat Hutchings and Dieter Hochuli (eds) The Natural History of Sydney, Royal Zoological Society of New South Wales