Death and good fortune on Cowan Creek

Since reading the poetic prose of H is for Hawk, Helen MacDonald’s story of how training Mabel the goshawk carried her through wild sadness that followed the death of her beloved father, it’s been all about the raptors around here.

Easter at Speers Point meant ospreys relaxing in the late afternoon sun.

And yesterday, on Cowan Creek, the contractual obligation white bellied sea-eagle.

Juvenile sea eagle belly horizontal

Juvenile white-bellied sea eagle

Then, just when I’d resigned myself to a pleasant if uneventful paddle after three hours on the water, there was an explosion of action right off my bow.  Two birds in an aerial battle, tumbling and squabbling over a kill.  The loser flew off, disgruntled; the death-dealer pulled up in the bright morning sunshine on a branch over the river, and waited for me to get out my camera.

A new bird!  One I thought I’d never seen on any waterway.  A peregrine falcon.

It turns out I had seen these birds before, long ago and far away – a pair tussling with ravens over a ledge to nest on at Malham Cove in Yorkshire.  Cliffs (or, if they are hard to find, skyscrapers) are one of the essential requirements of this beautiful raptor.  RB reminded me that peregrines used to nest in the ventilation towers of the tunnels under the River Mersey and high up in the Liverpool’s Anglican Cathedral, the enormous red sandstone building I could see from my desk during my decade as a Scouser.

Peregrines may be the most widespread bird in the world, living on every continent except for Antarctica and on many islands (although strangely, considering its status as a bird watching paradise, not New Zealand).  Its name is derived from the Latin for “the wanderer” although only five of the nearly twenty subspecies – those breeding in the northern Arctic – really migrate very far.

For all their capacity to adapt to life in the city – eating feral pigeons and nesting in highrises – peregrines are widespread but not really common.  Since they mostly prey on smallish birds, themselves often insect eaters, falcons bioaccumulate pollutants. The use of organochlorines in insecticides like DDT devastated their numbers in the second half of the twentieth century.  By the 1960s there were no peregrines in the Eastern US and the birds were declared an endangered species. Numbers have bounced back, in Australia and elsewhere, although they are still classed as  “rare” here.  And recent work in Europe and Canada has observed a new chemical – flame retardants – turning up in the blood stream of peregrine chicks.

Once peregrines find a good nesting site, it’s a keeper.  Apparently, a falcon skeleton found at the back of a cliff-top eyrie in Tasmania has been carbon dated at 19,000 years, which makes that spot the oldest known bird’s nest. As I noodled along the northern shore of Cowan Creek, I’d admired the 100 metre high cliffs of Looking Glass Spur, eucalypts halfway up the face finding impossible footholds in the sandstone.  I wonder if my falcon and its mate have a scrape there, high above the expanse of the estuary.  Peregrines don’t eat fish but hunting grounds by water offer the space for their deadly turn of speed.

I feel less disappointed by my failure to spot the raptor’s stoop or to capture the battle on film after I figured out what I was watching.  The fastest animal in the world, dropping  on its prey at nearly 400 kilometres an hour.  That poor bird clutched in its talons -maybe a galah, the favoured meal of the big-footed Australian “macropus” subspecies – never had a chance.

I watched for twenty minutes, as she plucked and dismembered her meal, unperturbed by the rowdy parade of jet skiiers, cruisers and powerboats.  Galah feathers drifted down from her branch, making a delicate trail of death across the bottle green water.

For a few dodgy moments, I thought the gobbets of galah might be joined by flotsam from my shattered craft as Egg was washed perilously close to oystershell sharpened rocks.  And, if I had the Bond-style rocket launcher I’ve often fantasised about while ploughing  through powerboat wakes on sunny Sunday mornings, fragments of several jet skis.

I’m guessing my peregrine was a “she”.  Females are a third bigger than the tiercels – the males – but I didn’t have the chutzpah to hurl a swiss army knife up the tree for scale.  The two mid-air combatants looked well matched – two males or two females. Definitely not a pair.  Since peregrines mate for life – up to 20 years – and often hunt cooperatively, it would seem to be unwise from the point of view of domestic harmony, anyway, to bicker over food.

In fact, Derek Ratcliffe describes exactly what I saw: “feet-grappling over disputed food items” which happens, he says, “at food-territory boundaries during the non-breeding season” (1993, 201).   It seems these battles are nearly always between birds of the same sex, although sometimes peregrines fight with other crag-loving birds as well.  RB remembers peregrines in springtime at the cliffs at Creagh Dhu, attacking ravens, stooping then zooming straight up to the heights to do it all over again.  Sometimes pairs of peregrines will even take on the great golden eagle over rare and valuable real estate.

So maybe there’s more than one pair of peregrines on that beautiful bit of country.  Perhaps I’ll see this magic bird again, or her mate, or her rival, until I’m as blase about a peregrine strike as a whistling kite soaring on a thermal. But yesterday, as I took my four hundred photographs while the peregrine peaceably disembowelled its meal, showing the equanimity that makes them the favoured hunting falcon, I felt truly blessed.

Peregrine in front of branch staring at me crop

Peregrine falcon watching the watchers

More stories about raptors in Berowra’s backyard (and mine):

The beautiful white morph of the grey goshawk in Bluetongue’s back

A hunting collared sparrowhawk in Nude trees and naughty birds

The whistling kites of Bar and Peat Islands in Two sad islands, three whistling kites

The many white-bellied sea eagles of the Hawkesbury and Lake Macquarie in Encounters with eagles

Sweetness and light

On our shady south-west facing hillside (who went house hunting without a compass, then?) there’s just one spot that gets plenty of light year round: not a bad place for some solar panels on the top of a pole. But right in that spot there’s a native tree, sweet pittosporum or pittosporum undulatum.  And there’s a healthy specimen of the same species dead to the north of our kitchen windows, right where the winter sun might otherwise beam through.

Hornsby Council is pretty proud of its status as a leafy north shore suburb – “The Bushland Shire” – and dissuades its rate-payers in the strongest of terms from cutting down trees.  But not this one.  Until 2011, despite its status as a native, gardeners had a licence to kill sweet pittosporum, along with a select few imported nasties – cotoneaster, camphor laurel, privet and coral trees. But now it’s a different story.  You can chop down quite a lot in Hornsby these days – pretty much any non-native tree.  You can even gaily hack down Australian natives that don’t hail from this part of the Hawkesbury.  But put that saw down!  Pittosporum is now right there on that not very lengthy list of protected local trees, shrubs, grasses and vines.  It’s a dramatic turnaround, from big-league environmental weed to local hero, all in the space of a single year.

So what’s going on here?  Tim Low’s immensely readable book, “The New Nature: Winners and Losers in Wild Australia” (Viking, 2002), a fat but fascinating volume filled with stories about birds and trees, insects and frogs and their complex inter-relationships with human beings, has a lot to say about weeds and natives, and in fact quite a bit to say about sweet pittosporum.  The essential argument of the book is that any quest to preserve untouched wilderness or to maintain nature free from human interference is not just doomed, but essentially ill-conceived.

Human influence has been making plant and animal winners and losers in Australia for many thousands of years, and Low documents not only the way some pragmatic species capitalise on urban environments (think peregrine falcons nesting in high rise buildings) but the way many others rely on continuing human intervention (like firestick farming or stock grazing) to survive.  Sydney’s green and golden bell-frog survives at the Brickpits in Homebush, a location described as “one of the most industrially polluted in the Southern Hemisphere” (24) because these frogs are tolerant of high levels of heavy metals, while the frog-killing chytrid fungus is not. Low points out the limitations of the distinction between “native” and “exotic” as a way of gauging the impact of animals and plants on biodiversity, and argues that decisions about what to conserve and how to do it, are in short, very very complicated.  Koalas can be forest killers and cows can step into the gap left by extinct megafauna in maintaining diverse grassland.  As a greenie and a gardener, I found the anecdotes and ideas in “The New Nature” provoking and intriguing, making me take a good hard look at my weed anxieties and my fantasies of a bird-friendly, local provenance garden.

Hornsby Council’s change of heart about sweet pittosporum illustrates Tim Low’s arguments beautifully.  Don Burke, the Australian Native Plants Society of Australia, Grow Me Instead (The Nursery and Garden Industry Association) and the Queensland Government all agree that it’s an invasive weed. “The New Nature” with its ambivalence about such terms calls pittosporum “our worst native weed” (250), “replacing diverse systems with monoculture” (201).  While a canopy of eucalypts allows a rich understory, pittosporum shades out nearly everything else (although that nasty garden escape, privet, apparently copes well).  Birds enjoy the pittosporum’s orange fruits and disperse its sticky seeds.  Not needing fire or light to germinate, and tolerant of richer soils than many other natives, pittosporum is a native to this neck of the woods, flourishing on the shale ridgetops on Hawkesbury sandstone – most of which are now built on.  Run off from houses and gardens has enriched the sandstone soils on the slopes and pittosporum has moved on in.  According to Low, “If you take eucalypt forest, add fertiliser and water and take out fire, you have a recipe for rainforest.  The pittosporum invasion is really a takeover by rainforest” (248).

Pittosporum undulatum has its defenders.  Jocelyn Howell from the Royal Botanical Gardens suggests that pittosporum can shade out and outcompete other more troubling weeds (although Tim Low would argue that even invasive weeds like lantana can play their own role as a habitat).  Others argue for it in terms of the food supplies it offers and the fact that it *is* a local really. Obviously, Hornsby Council has plumped for this point of view.  Most of the advisories suggest that it’s a weed only outside its home range, using provenance to distinguish true locals from native invaders.

But according to Low’s arguments, its home range isn’t the home it once was.  His book gives poignant examples of Sydneysiders talking about the impact of pittosporum (“pittos”) in terms of solastalgia, the sense of homesickness you have when you haven’t left home, but your home has changed forever.  Orchids and grasses gone, along with the smell of eucalyptus (248).  There are no easy answers here: it’s “a hard one”, “one of the most sensitive issues around” (249).  Are the eucalypt forests of the Hawkesbury slowly morphing into (monocultural) rainforest?  Will the catastrophic fires I expect and dread drive it back?

From a more selfish point of view, it seems like my kitchen windows will remain gloomy and my solar panels a dream, even as my fantasy as a kid growing up in the arid lands of the South Australian mallee, of coming home to a rainforest seems to be coming true…