Black princes, redeyes and floury bakers

My brother the twitcher has taught me the secret of finding birds.  Tune into sound: let your mind move out from the place where you are standing, into the space above you and all around you and listen.

All this summer, I’ve been listening out for the sparrowhawks.  Even lying in bed or sitting on the sofa, we could hear them begging for food or squabbling with the local cockatoos.

But come mid December, white noise and static started interfering with Radio Sparrowhawk.  The cicadas had arrived.

This year’s a biggie for cicadas in Australia.  Over 350 species of cicada have been described here, though there could be many more – we’re a diversity hotspot for these charismatic insects.  And this summer, some of the biggest and noisiest species – the cherrynoses, the double drummers and the razorgrinders – have appeared en masse around Sydney.  After maybe five or six years of living metres underground sucking on the tree-sap, the cicada instars crawl out of the earth and shed their exoskeletons for a short and noisy month or so as adults.   It doesn’t happen every year.  2013 was a big year for cicadas in Sydney, and before that 2010.  And now it’s on again.

Black prince 1 closeup nice background

Black Prince on a casuarina tree by the edge of Berowra Creek

No-one knows quite what triggers the horde of insects.  In fact, no-one knows much about cicadas at all, despite their presence on every continent except Antarctica and their impossible to ignore, earsplitting calls.  That long and decidedly boring youth, and the uncertainty about when they’ll re-emerge, makes researching them tricky.  Imagine deciding to study the periodic cicadas of North America and then realising your three years as a PhD student would be over long before the seventeen years the critters spend underground was up?

An ex cicada thanks to the local orb spiders

One theory is that by appearing so infrequently and irregularly cicadas could avoid the predators – bird, bats, all sorts of mammals – keen to feast on the insect bounty.  Very weird recent work from the US suggests that numbers of predating bird species start to drop around twelve years after the last cicada boom.  Could it be that these devious insects are manipulating the beasts far higher up the food chain?

In some ways, despite its wealth of cicadas, Berowra is less interesting for researchers than bits of Sydney not surrounded by national parks.  Australia cities are unusual, it seems, in that they still have cicada species in the heart of suburbia.  Silver princesses and green grocers survive in quite urban areas on the east coast. A local researcher (plants by day, cicadas by night) Dr Nathan Emery has been trying to work out how these species have survived, and whether there are others that can cope with city life. He’s set up the Great Cicada Blitz, a citizen science project crowd-sourcing information about when and where various species of cicadas can be found.

I’ve had a great time over the last month wandering around recording the din in our neighbourhood and trying without a lot of success to spot the earbleedingly loud cicadas to add to the Blitz database.  The male cicadas’ strategy to collectively produce a chorus so loud it hurts the ears of birds works on humans too, even those with the advantage of being partially deaf already. Apparently even the males cicadas “switch off” the equivalent of their ears (their tympana) to save their own hearing.

Thanks to helpful tips from the experts as they confirm my dodgy IDs, I’m slowly learning how to identify the common species around these parts.  Nathan Emery’s nifty little book A Photo Guide to the Common Cicadas of the Sydney Region has been really handy too. It has a lovely introduction from (and is dedicated to) Dr Emery’s scientist dad who took him and his siblings out cicada spotting as kids – inspiration to continue tormenting my offspring with my nerdy passions.  And who wouldn’t be nerdy about cicadas – an animal whose wings has in-built nanostructures that literally rip bacteria apart…

Graphical abstract

Graphical abstract for Aaron Elbourne, Russell Crawford and Elena Ivanova’s 2017 article “Nano-structured antimicrobial surfaces: From nature to synthetic
analogues” Journal of Colloid and Interface Science 508 603-616.
Shouldn’t EVERYTHING have a graphical abstract?

I should also thank the popularity of the big liquidambar in our front yard with the local insects for the chance to improve my cicada identification skills.  Adult cicadas like to latch onto thin-barked natives, but if push comes to shove they will feed on introduced trees, and liquidambars seem to be a favourite, of our local population of redeyes at least, although I think I’ve also heard calls from local tibouchina and robinia trees, as well as the local Sydney red and blue gums.

Though some cicadas don’t seem to be too fussy about the trees they sup from, you have to worry for the next generation.  In the last year, 15,000 trees – 3% of the tree cover on private land in Hornsby Shire – disappeared, thanks to a rash of tower buildings replacing the old fibros with rambling jungly backyards that used to hug the railway line.  Next gen cicadas popping out about 2023 may find nothing taller than a cordyline to sing from and property developers taking over their traditional role local bloodsucker.

Rough barked tree with cicada shell bettersquare

An exoskeleton clinging to the bark of a tall tree in a local school

I’ve not seen any green grocers or yellow mondays or silver princesses around here.  There are double-drummers in the national parks down the road – they don’t do so well in back gardens, needing an expanse of acreage or bushland to survive.  And so far we’ve heard at least four species around our yard: razorgrinders, black princes, floury bakers and the locally ubiquitous redeyes.

One of a whole bunch of redeyes high up in a Sydney red gum raining down excess tree sap on me

How do I know the red eyes are one of the most common cicadas around these parts, even before I started collecting photos and audio?  Well, that’s the gossip from the local kids.

Cicadas weren’t a feature of my childhood, growing up by the River Murray in South Australia.  But they’re a big part of children’s lives around here.  Even the common names of the local species are courtesy of kids, which explains why they are named after colours or days of the week and not dead white European men as per normal service!

My younger daughter (Anonymous Bob as she wants to be known) gave me the low down on what Berowra kids know about cicadas:

“At school in the cicada season, when the teachers aren’t looking, people climb the trees to try to catch cicadas. They climb the big thick trees because that’s where you find them. The main cicada zone is the little mossy grove next to the library. We treat them like exotic pets and look after them, until they want to be free or they die.

Once, there was a little boy. An older boy gave him a cicada to look after – it was sort of like an adoption. But the little boy decided to let him go so he could be free.

Another time, a bunch of kindies robbed a guy of his cicada. It was freshly caught and it had one leg missing, so he was desperate to protect it. They wanted to call it Princess and he wanted to call it Jeffie. They threw a ball at it while it was clinging to his shirt. It nearly fell off and died. And then the kindies started chasing the guy saying “Princess! Princess!” and then they had an attempted robbery but then a teacher came.”

Jeffrey Princess

“It’s fun to look after the cicadas. They’re kinda cute. Most cicada collectors try to find other species because in our school the redeyes are the most common. We find what they eat and take care of them. The cicadas cling onto your clothes which makes them pretty portable pets.”

Red eye cicada

Red eye at our place

“A while ago we did a thing where we would prank the teacher with cicada shells.   At first it was just a joke and then it became a whole fiesta. It became a game and a compulsory activity. Not that the teacher said it was a compulsory activity, we just made it one.

Originally it was just seven cicada shells a day but it ended up with many many many shells from each person. We gathered cicada shells, and every day we would leave cicada shells around the classroom and she would have to find them.”

Many cicada shells

A very popular grapefruit tree in my neighbour’s garden

“We found the cicada shells everywhere – on plants, on trees, on everything. A few boys were the main gatherers. They did it at school, home, everywhere. They came in with huge plastic bags full: they were the main source of our cicada shells. Sometimes we used white out and sharpies to paint war paint onto the cicada shell to make them unique.

Cicada on key ring

Graphical abstract of cicada exoskeleton on teacher’s key ri

You know how cicada shells have a slit? We slipped that onto the teacher’s key ring and when she found it, she was like “Not again!”. We started making a joke that she was cursed by the demon of cicadas.

At the very end of the year a few of the boys laid the cicada shells in a big love heart on the carpet and put a huge pile of chocolates in the middle and wrote their names on a card with love to the teacher.”

 

Cicada love heart

The love for a teacher expressed in the language of cicadas

Maybe there’s another project to be done on cicadas – a children’s natural history of these rowdy, charismatic insects…

Do you have any stories of childhood exploits with cicadas, in Australia or further afield?  I’d love to hear them!

Sparrowhawk summer

The sparrowhawks in the bottom of the neighbour’s yard have beaten the odds.  Despite the visits of the hungry currawongs and randy cuckoos, two strapping fledglings have emerged from the nest this week.

Two juvenile sparrowhawks trying out their wings

Our days are punctuated by the insistent call of the mother and father hawks telling the teenagers that it’s time to head back to the ridiculously tiny nest for dinner.  And the juvenile’s answering pitiful cries, disproportionate to their galumphing size.  They’re easily as big as their parents even at this early stage.

Photo of juvenile sparrowhawk with its mouth open

Fledgling sparrowhawk talking back to its parent

And early in the morning, the ding-dong battles between the sparrowhawks and the local mob of sulphur crested cockatoos, that wheel across the valley each day to find the tastiest trees and finest roosting places. The hawks have been watchful but apparently unconcerned by the range of large and small humans arguing, gardening, driving, swimming and playing beneath their nest and, as you can see, endlessly photographing their activities.

But the arrival of a crew of a dozen or so seed eaters in their territory was apparently intolerable.  A crested pigeon is the biggest prey sparrowhawks have been known to take, but we’ve seen for ourselves they’re not afraid to send cockies and cuckoos packing.  The cockatoos didn’t take off without a bit of argy bargy but in the end the diminutive predators won the day.

The flock retreated off to our place, and relieved their frustration with some light demolition work on the rotting pine tree in our backyard.  I assumed it was the parents that did the chasing off, but Stephen Debus, who spent a lot of time hanging out in the Bundaberg Botanical Gardens with a digital camera and a pair of young sparrowhawks, seems to think that the young ones like to chase away bigger birds that they couldn’t possibly eat, everything from egrets, darters and ducks to kestrels and even currawongs, their erstwhile enemies.

There’s been an exciting new development in the last couple of days: the littlies are trying their hand with disembowelling.  Young nestlings are fed gobbets of freshly plucked bird flesh, straight from mum or dad’s beak, but this youngster was doing his own kitchen prep.  It took him a while.  Given the eye-claw coordination on display here, it may be a few weeks before this one is hunting on its own.  It seems that taking dinner from the talons of parents mid-air (and maybe snacking on cicadas in between meals) is the next step towards independence.

From the vantage point of our neighbours’ pool, we’ve watched the fledglings practicing their short haul flights (and awkward landings), whine a lot and bicker over food.  In a truly rare sighting, judging from my experience with human children, I even saw one of them give in to his sibling’s relentless complaining and share a meal.

Or maybe what I saw was big sister muscling in on little brother?  Sparrowhawks have distinct sexual dimorphism, and apparently any idiot can tell the smaller males from the females.  Not this idiot!  I look forward to being enlightened by sharp eyed readers.

As you can tell from the recent posts in this blog, I have got just a little obsessed by our in-house raptors these last few months.  Maybe because our four serial killers have cleared the area of other distraction – the usual “house” birds.

No baby brush turkeys this year (hooray!) and the noisy miners have been mercifully silent. But the gorgeous satin bowerbirds have also been thin on the ground, the newly arrived whipbird disappeared suddenly without leaving a forwarding address, and I’ve heard very few of the chocks and clucks of the wattlebirds that make up the usual soundscape of our neighbourhood.

We have about six weeks, it seems, before the young sparrowhawks will disperse, looking for another neck of the woods with the requisite tall trees for nesting and plenty of small gormless birds to ambush from a secret spot in the canopy.

Will the adults stay after the brood has gone?   Will they leave and come back next year?  It seems no one really knows much about the movement of these secretive birds, despite their presence all over Australia, in every habitat but the driest of deserts.

And, if our lovely raptors do leave us, will our usual cast of feathered friends – the nectar drinkers, the seed and flower and lerp eaters – return?

Further references

Barnes, C.P. and Debus, S. (2014) “Observations of the post-fledgling period of the collared sparrowhawk (Accipeter cirrocephalus)” from The Sunbird (2014) 44(1): 12–23

Debus, Stephen (2012) Birds of Prey of Australia: a field guide, CSIRO Publishing

 

More sparrowhawk stories from our backyard

The end of the brush turkey plague? The battle of the baby birds….

There’s a collared sparrowhawk nesting in our garden…. or is it a goshawk…?

and the latest from our backyard: the teenagers start hunting for themselves… Sibling rivalry amongst the young serial killers….

 

 

 

Battle of the baby birds

There’s a festival of death going on in our neighbourhood at the moment.

Several times a day, amongst the robotic clicks of the bower birds and the squawks of the wattlebirds, there’s an insistent high pitched chittering call, often accompanied by the din of freaked out noisy miners.  I’m not 100% sure of its ethological or evolutionary significance, but as far as I’m concerned it’s a signal for me to drop everything and dart up our drive with my camera.  One of the resident pair of collared sparrowhawks – probably the male – has caught some small clueless bird and is perched in our neighbour’s radiata pine steadily eviscerating it.

He rips off the feathers and flings away less tasty bits (check out the beak mid-air above) all the while, often with his mouth full, calling out “Dinner’s up!” to his mate.

For the last few weeks she’s been spending much of her time in a the nest at the very top of another decrepit pine tree in the yard of next house along the way.  Sometimes he flies up to the nest with tasty chunks of flayed bird flesh in his claws, but I’ve also seen her fly in to the designated “disembowling” perch to join him a few times.  Occasionally, she seems to sneak away to do a little light hunting herself.  Risky, though, leaving the nest unattended.

There’s the pied currawong I saw hopping surreptitiously through the branches, warily inching towards the nest, until it was chased off by the indignant parents as it was virtually peeping over the side.  And the pair of cacophonous channel billed cuckoos I caught flapping around the neighbour’s garden a few weeks ago – apparently they sometimes parasitise collared sparrowhawk nests.

But I will be deeply unimpressed if the chicks that come out of that nest are bloody channel billed cuckoos, for all my secret admiration of those giant hornbill beaks and strapping crucifix silhouettes.

Because the sparrowhawks seem to have rid our garden of the plague of baby brush turkeys.

A whipbird seems to have taken up residence this spring.  Needless to say, I don’t have a photograph despite being nearly eye to eye with the noisy bugger once or twice.  So, tiptoeing round my backyard trying to catch a clear shot, I heard a scrabbling in the leaf litter.  “Ah, a baby brushturkey” I thought sagely.

And then it struck me… I haven’t seen a single baby turkey in our backyard this year.  Not one!  Last year, they were sleeping on top of the predator proof cage or standing outside in the daytime, gazing longingly at our flock of little baby chooks.  The year before one wandered into our pocketsized laundry and spent eight hours pacing the two foot long windowsill, failing to notice and thus escape through through the wide open door.  But this year… nada.

Collared sparrowhawks (unlike their lookalikes brown goshawks – so similar that it’s altogether possible they could be our resident raptors) catch most of their prey in flight, bursting out of their lurking places in the foliage to grab little birds on the wing.  But the baby brush turkeys that previously haunted our place do fly, right from the day they dig themselves out of their hatching place in their father’s mound of decomposing leaf litter, and start their life of unnaturally early independence.

So maybe the sparrowhawks have been catching them on those very first short flights from mound to chicken yard.

I don’t hate brush turkeys, but I do hate a having dozen brush turkeys hanging out in my backyard, sexually assaulting my chickens, nicking their food and, given half the chance, eating their eggs.  So the idea of generations of sparrowhawks breeding happily in the neighbour’s trees and keeping the local population to manageable levels is extremely appealing.

I’m starting to wonder if there’s a connection between the familiar sound of chainsaws and the plague populations of brush turkeys in Brisbane and the northern suburbs of Sydney over the last few years.  No dingoes, fewer foxes foxes thanks to baiting, and nowhere much for the local raptors to nest in suburbia these days, the tallest trees victims of fears about bushfires and death-dealing or at least car-damaging falling branches.

But today my endless blurry photos of the neighbourhood raptor nest brought good news: what seems to be a creamy ball of fluff snuggling up to its mum in the distant collection of sticks that is the sparrowhawk’s nest.  Bring on the next generation of brush turkey assassins!