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….

 

 

 

Autumn in terminal decline?

In amongst the nasty consequences of global warming – sea-level-rise-ocean-acidification-violent-storms-heat-waves-large-scale-extinctions (if you say it quickly and rock back and forth at the same time it doesn’t seem quite so bad) – a decline in the intensity of autumn leaf colour really doesn’t draw the eye.  Bar a few unusual plants like the red-fruited kurrajong and the Antarctic beech, most deciduous plants around here aren’t even natives.  So who cares, eh?

But as I huddle in my chilly house on its shady south-facing hillside, waiting for the leaves on the neighbour’s looming liquidambar to fall, the impact of climate change on deciduous trees seems like a tremendously pressing question.

I’m not the only one gripped by this crucial topic.  The latest  Trends in Ecology and Evolution has roundly denounced the scandalous neglect of autumn. Spring gets its own live feed on BBC TV, but even scientists get depressed by extended discussions of leaf senescence, it seems.   Garnering less than half as many articles as its greener sibling, autumn, according to the indignant authors, is a “neglected season in climate change research”.

Well, neglected no longer!  Not here in the backyards of Berowra.  Right here, right now we bring you…. in the prophetic words of Gallinat and her outraged colleagues… “the future of autumn research”.

As we march boldly into fall’s future, I’m cling to the hope that photoperiod (that’s the day-length to you and me) will rescue me from climate change, sending that winter-sun-blocking foliage promptly into the compost bin regardless of how roasting hot it is. And it’s not a vain hope – the amount of light a deciduous plant receives does seem to help many decide whether it’s time to shed their leaves or not.

In the case of liquidambar, long days or lots of light delay dormancy, as you can see from these nifty pictures of a specimen down the street, well illuminated day and night so as to minimise deaths on a local pedestrian crossing, clinging to its leaves long after its neighbours have shrugged their own.

Depressingly, it does seem that sweetgums need cooler weather to finally ditch their leaves, even in the short days of midwinter.   Photoperiod matters most near the poles – but for trees at the lower latitudes (like Sydney, curse it) temperature is the clincher.

This raises interesting questions about the future of the veggie garden. Around the winter solstice it lurks in the shade of our dawn redwood, a living fossil that grew across the temperate Arctic when dinosaurs stomped the earth, and was dramatically rediscovered in the 1940s in a single isolated valley in China.  Will its gorgeous copper needles still fall in time to give my broadbeans a decent run-up to spring when we’re wearing shorts all winter?

In the words of a Facebook status update, “it’s complicated”.  Could this be why climate scientists, like nervous singles, are staying well clear?

For instance, warmer springs lead to earlier bud burst, which can sometimes mean earlier leaf-fall.  And deciduous trees in general tend to lose their leaves more readily in dry weather.  “On average”, according to Estiarte and Peñuelas (2015) “climatic warming will delay and drought will advance leaf senescence”.  Work that one out.

And that’s not even throwing nutrient availability into the mix.  For instance, what if trees start going ballistic with all that carbon dioxide in the atmosphere?  This vision of a greenhouse planet jungle awash with joyful plants growing at breakneck speed sounds like something out of a climate denialist fantasy, doesn’t it?  “More open cut mines, pretty please!” beg the earth’s desperate forests “my future is coal!”

Sadly for the wind-farm haters, it mostly doesn’t work like that.  Carbon dioxide can give trees a flying start but eventually the nitrogen supply conks out, or drought and too much CO2 do the leaves in.  Even with the help of globe-trotting survivors like sweet gums and dawn redwoods, coal (and copious quantities of greenhouse gases) won’t make the world greener.  Let’s just hope, even gardening in our bikinis, we can still find gold.

References

  1. Estiarte, M and Peñuelas, J (2015) “Alteration of the phenology of leaf senescence and fall in winter deciduous species by climate change: effects on nutrient proficiency” from Global Change Biology 21(2) 1005-17
  2. Flexas, J, Loreto, F and Medrano, H. (2012) Terrestrial photosynthesis in a changing environment: a molecular, physiological and ecological approach, Cambridge, Cambridge University Press
  3. Gallinat, AS, Primack, RB, Wagner, DL (2015) “Autumn, the neglected season in climate change research” from Trends in ecology and evolution 30(3)
  4. Warren JM, Jensen AM, Medlyn BE, Norby RJ, Tissue DT, (2015) ‘Carbon dioxide stimulation of photosynthesis in Liquidambar styraciflua is not sustained during a 12-year field experiment’, AOB Plants, vol.7, Article no.plu074
  5. Warren, JM, Norby, RJ, Wullschleger SD (2011) ‘Elevated CO2 enhances leaf senescence during extreme drought in a temperate forest”.  Tree Physiology 31, 117-30
  6. Worrall, J (1993) “Temperature effects on bud-burst and leaf-fall in subalpine larch” Journal of Sustainable Forestry 1(2)

Let them eat light!

It’s persimmon season, but, natch, nothing doing on my little Nightingale tree, despite a grand show of weird naked-looking flowers in the spring.  Two fruits nearly made it to the finish line, but the possums got there first.

Gorgeous as the golden fruits are reputed to be as they hang on the leafless trees, 2016, I have decided, will be the year of picking green. The persimmons may well be mouth-puckeringly unripe but as human overlord of this place, I insist that it is I who will enjoy their high-tannin nastiness, and not some upstart marsupial.

In fact, my tree is an old fashioned astringent persimmon: the fruits need to be “bletted” to go super soft and sweet. This can happen far from fruitflies and other critters, deep in the pantry, in the comforting darkness of a paper bag, with only an ethylene-emitting banana for company.  I have days when crawling in next to the banana to be bletted myself sounds like a good gig.

In theory, me and my persimmons can hole out for a few weeks in an undisturbed corner and it should work out delectably for both of us.

But, really, I don’t care! Harvests mean nothing to me! A barren tree is a beautiful tree.

For now, it’s all about the komorebi, a Japanese word I encountered for the first time a few days ago in the marvellous nature blog, Mildly Extreme.

Because who needs food when you can have sunlight filtering through though autumn leaves?*

*Love those leaves… but thank god for the Freemont mandarins

Timber!

We’ve had a mob of at least fifteen yellow tailed black cockatoos hanging around in the last few days, mewing like strangled cats and being chased around by magpies and (I think) even noisy minors.  We get the yellow tails quite often around these parts, especially in the winter-time, thanks to the large and sickly but apparently tasty radiata pines that loom over our place.

The rule in Hornsby Shire is you can cut down a tree that’s within three metres of the foundations of your house.  If only there was some special by-law where the council chops down the tree for you for free if you can’t slip a paperback book between a towering pine and your bathroom.  One of these days I’ll be communing with nature and the nearest treebole will swell just that tiny bit further and burst straight through into the shower cubicle. That fresh piney smell with not a cent spent on disinfectant.

It’s been very very very windy in Sydney lately, and quite a few people have been unfortunate enough to experience that piney odour, quickly followed by plenty of refreshing indoor rain. We’ve been pretty lucky, but we’ve spent a lot of time staring anxiously out the window at various ominously swaying monumental specimens.  When I lived in Brisbane I used to be a bit judgey about the lawn to tree ratio in most peoples’ yards.  But if cyclones start creeping their way down the coast I may have to reconsider.

Yellow tailed black cockatoos are doing pretty well on the east coast, including urban areas, no doubt thanks to their penchant for pines.  But apparently they often struggle to find nesting sites, preferring hollows in trees a century or more old.  They seem to like our senescent radiatas, and spend time perched high on the various dead branches voguing.  I hope, when we finally save enough shekels to pull down the extensive array of dangerous trees in our yard, we still see them.

Ecosystems of evil

Okay, I know there’s no such thing as evil ecosystems.  You create plenty, and things come.  Plenty of chicken food and regular eggs, you get nine teenaged brush turkeys, slouching around your backyard, eating anything that’s not nailed down.  Lots of grapes vines and your resident possums bite their way through the mesh exclusion bags and let in the fruit flies.  A yard littered with the sulphurous fermented droppings of a cocos palm (not to mention the ordure of those brush turkeys), you get loads and loads of flies.

I’ve had a red hot go at taking an aesthetic approach to the flies, with their sparkling metallic blue and golden armour and crazy eyes.  I’ve tried to think about them as simply part of the cycle of life, but I am starting to stare pointedly at my watch, waiting for the arrival of the cavalry, a wheeling flock of insectivorous SBBs (small brown birds) that will weave through the undergrowth and snatch the pests from the air without breaking formation.  I want one of those neat and tidy ecosystems, the ones where the annoying insects become a food source for endangered and good-looking avian visitors.

But no – desite my native shrubs and the absence of a horde of noisy miners, our place is rich in  bombastic generalists and SBBs are thin on the ground.  Your kookaburra – good for tidying up your left over sausages. Your cockies will make short work of the peach crop.  But both of them bloody useless at disposing of flies.  The garden skinks have been a disappointment as well.  Allegedly they are avid carnivores, and flies are a favourite treat, and we’ve got more Lampropholis guichenoti in the backyard than we have five cent pieces rattling around in the bottom of the washing machine.  But they, too, have failed to come to the party.  Once again, Gaia appears to be napping on the job.

While the Cocos palm absolutely and definitively a weed (I like the nuggets of invective in the Grow Me Instead Brochure – “a blot on the landscape” “can give the appearance of a garden planted with telegraph poles”) my hatred for this vermin-attracting plant was masked for a while by a sense of gratitude.  After all, it did save the house and possibly the family from being crushed under a giant gum tree.

I was at work one day when RB called.  “I don’t want to worry you but a tree’s just fallen on the house”.

The SES was summoned: a marvellous mob of guys and gals with chainsaws who belayed themselves to the wonky car port and swarmed over the roof of the house, making short if noisy work of the tree.  The big gum had lost its grip on the ground and fallen sideways towards our verandah.  Fortunately a forked branch wedged itself across the Queen palm, holding the eucalyptus suspended just a smidgen above the roof. The sum of the damage: one branch lightly brushed a gutter and gave it a bit of a bend.

So, thanks for that, Queen palm (and, needless to say, the SES. You are legends.).  We’re grateful for the structural integrity of our roofline.

But if you think it’s going to stop us chopping you down, you couldn’t be more wrong. The possums might view your fruit as ideal picnic food but you’re a hazard for the flying foxes.  It’s a worry when you rely for 30% of your diet on something that gives you acid reflux, damages your teeth, chokes you and leads you to stumble around on the garden being mauled by suburban dogs.  Even Maccas isn’t that bad.  That’s an evil ecosystem if ever there was one.

And that’s leaving aside the trip hazard for someone as poorly coordinated and lazy with the garden broom as I am.  So unless I hear about a recipe for cocos palm wine before I afford a tree surgeon, Cocos palm, you’re cactus!

Pomegranates: a Christmas star turn

My little pomegranate, a variety called “Wonderful“, is living up to its name. The flowing scarlet flamenco skirts of the flowers don’t last very long, but in a kind of floral Eurovision stunt, once the maxidress is off, there they are in their nifty stellar mini.

Of course, just because they’re looking gorgeous now, doesn’t mean any of these beautiful budlets will go on to become proper grown-up fruit.  The tree struggled on for a few years in a pot, and only gave us our first taste of success when it finally went into the ground last year.  And festive as it is, I’m not sure what to read into the flurry of fallen starry frocks underneath the tree.

Apparently pomegranates don’t like humidity much, especially in the spring time. The rigorous raking its roots were getting from feathered visitors up until recently probably didn’t do much for it either.  I sorted out that problem by piling rocks and tiles on them – the pomegranate roots, that is, not the brush turkeys, although the thought of burying a turkey or two under an avalanche of bricks is pretty appealing.

I’m hopeful we’ll see a better crop this year.  A tree with a 5,000 year old history of cultivation has got to be tough as old boots, I reckon. Unsubstantiated rumour has it that the pomegranate may even have been the “apple” that Eve was tempted with by the diamond python of the Garden of Eden.  Surely a participant in that epic contest between good and evil (or at least, between nudity and a well supplied fruit bowl) will be able to handle a tussle with a chook or two.  With luck, in the spirit of this year’s glamorous bearded Eurovision winner Conchita Wurst, our feisty femme will “rise like a phoenix” above her stack of stones and discarded finery.