September 26, 2017

Swallows a certainty of spring

In fast-paced, troubled times I increasingly look for certainties, the rituals and rhythms of life that tell you all is well with the world.

Being a nature lover, my certainties are generally geared to the seasons and there is nothing as certain, or reassuring, as the arrival of the welcome swallows on my patch in spring.

Over the years – 17 in fact – I have always timed them for the first weekend of September. The first sight of their erratic, joyous flight brings with it the vision of summer, even if more often than not snow lingers on the summit of kunanyi/Mt Wellington.

I had high hopes of a bumper swallow spring when one of my correspondents David Kernke, the owner of the Shene historic home at Pontville, phoned to say that swallows had arrived there in mid-August. I counted down the days from that moment expecting at any time to see the swallows further south at the Waterworks Reserve. I waited in vain, and the swallows were still not in my neighbourhood past their normal arrival date.

Migratory birds of many species usually arrive on friendly, warm winds blowing in from the north and this year I noted that the normal swallow arrival time had coincided with a cold snap with snow-laden westerly and south-westerly winds.

In the past I might have simply put down the swallows’ late arrival to unfavourable weather but in these uncertain times of declining bird populations the arrival of spring and its certainly has been marked by a growing anxiety about how Tasmanian birds are faring during the winter months on the mainland.

Numbers of the migratory birds are showing marked declines across the world. Among them are the world’s swallow species. The barn swallows which breed in the United States and Canada are arriving in lesser number from their wintering grounds in South America, and there is also a marked fall in the number of European swallows whose trans-continental flights link northern Europe with the far tip of the African continent. The European swallows’ cousins, the house martin and the sand martin, are also falling to arrive in the numbers of old.

Ornithologists are still seeking the reasons for the decline but two factors are thought to be in play regarding the European species at least: land clearance which results in less flying-insect prey and increasing global temperatures, which are leading to desertification and drought in Africa.

So far I haven’t seen evidence of dramatic declines in Australian swallow and martin species but  our swallows and other migratory birds cannot be divorced from the factors that are affecting their number in other parts of the world.

On a more positive note, my anxious wait for the swallows ended within the first week of September. A merry twitter across the twin lakes of the Waterworks Reserves put my mind at rest, at least until next year.

My book on kunanyi/Mt Wellington, The Shy Mountain, is being launched by Charles Wooley at the Hobart Bookshop on Wednesday, September 20th. All welcome.

Street-wise sparrows and miners

Like their cousins in Melbourne, sparrows resident in Salamanca Square have learned a crafty tick to get them a meal.

Some years back a friend said that he had observed sparrows hanging about outside the McDonald’s restaurant in Swanson Street, waiting for patrons to trigger the electronic sliding doors. As soon as the doors opened, the sparrows flew into the restaurant, had a quick feed of fast-food crumbs and then waited for the doors to open again.

On a trip to Melbourne I observed the smart behaviour myself, but thought then it was merely a one-off perhaps, the Melbourne sparrows were more street-wise than those from further afield.

Well, I’ve been proven wrong. Sitting in Banjo’s in Salamanca Square a few weeks back I saw the cheeky sparrows doing the same thing there. Only difference, the main door at Banjo’s is not a sliding one but still the sparrows, both in and out, waited patiently for the door to be opened by patrons.

All this proved interesting food for thought as I killed time before I waited for  my destination on the day, the Hobart Bookshop in the square, to open. A little later I learned of another interesting snippet of information concerning birds making themselves at home in mankind’s environment.

Apparently, a flock of noisy miners in New South Wales have learned that the pickings at restaurants do not just include crumbs and scraps.

The miners frequenting a restaurant in Woolongong have really set out to embrace the café culture by stealing packets of sugar from the al fresco tables.

The miners fly to the tables of unsuspecting patrons and in a flash lift a packet of sugar from the sugar bowl and then fly to a convenient spot beyond the restaurant to tear open the sachets, and eat the sugar.

We might be used to sparrows, pigeons and gulls raiding outside, and sometimes inside, tables at eating establishments but the noisy miners must be the first among a family not known to associate closely with humans, the honeyeaters, to exhibit such bold behaviour.

With their stocky appearance and pugnacious behaviour, noisy miners might not look like honeyeaters but they are firmly placed among the 66 honeyeaters found in Australia, the country’s most prolific bird.

Many people confuse the miner with a similarly named bird, the introduced hill myna found in many mainland cities, but thankfully this pest species is not present in Tasmania.

The noisy miner – appearing grey in appearance instead of the myna’s black – is generally found in the more drier areas of Tasmania, particularly near the coast.

I’m not a big fan of noisy miners, mainly because they bully other birds, but I was so intrigued when I learned of their sugar stealing antics I did a little more research into the Wollongong gang.

It appears these noisy miners are very fussy about what they steal. They deliberately choose the packets of sugar – both white and brown – to eat, but leave sachets of artificial sweetener untouched.

 

Little battler survives in mankind’s world

Against the odds, the little battlers of the Derwent, its penguins, are maintaining a flipper-hold in what has been their home for millennia.

On a cruise around the river and wider estuary in mid-August I was pleasantly surprised to count several rafts of little penguins on open water stretching from the shores of Tranmere to the south, to within sight of the zinc factory to the north.

The convenor of BIrdLife Tasmania, Eric Woehler, confirms that the penguins appear to be holding their own despite all the trials and tribulations that make  life difficult in an environment increasingly shaped by mankind. These include frequent attacks by dogs on beaches where the penguins have their burrows.

It comes as a surprise to many people when I mention it is possible to see penguins in the Derwent. Colonies and individual burrows are kept a closely guarded secret but I know of one set of burrows within a few minutes of the Hobart town centre.

Habitat loss, or the loss of quiet, undisturbed breaches where nesting burrows can be located above the tide line, is also a major reason for penguin decline over the past 30 to 50 years. Another major threat is the use of catch-all, unattended fishing nets which in other parts of the country are banned. These nets anchored in such places as rock pools present a death trap not only for penguins but other seabirds like cormorants.

Penguins might be a vital component of Tasmania’s tourism attraction but some selfish and uncaring tourists have had an unfortunate impact on penguin numbers, not so much in the Derwent but on Bruny Island where there is still a sizeable little penguin population.

At penguin viewing sites on the Neck linking north and south Bruny island tourists have been seen digging penguin chicks out of borrows so they can feature in “selfies” from the Apple Isle.

Dr Woehler said that he suspected that most of the birds I had seen from the deck of the Odalisque tourist vessel – resting up in the Derwent out of season from its regular operation at Port Davey in the south-west – were “prospecting” birds swimming the Derwent looking for nesting sites.

“We have birds in burrows at the moment and I was on Bruny Island in mid-August, at the Neck, and there was plenty of evidence of penguins ashore,” he said.

Birdlife Tasmania – which has been compiling avian population and breeding records for half a century – has also seen a shift in the breeding phenology of penguins in south-east Tasmania.

“The old paradigm of spring arrival, summer breeding and autumn moult is long gone,” Dr Woehler said.  “Now we are seeing winter and late winter occupation and occasional breeding, late spring and early summer breeding and even late summer and early autumn breeding, then moult.”

He said penguin breeding in Tasmania was increasingly meshing with the nesting period of mainland colonies where water temperatures were higher.

It all raises the question of whether global warming if starting to have an impact on penguin behaviour in Tasmania, with unknown consequences.

Only time, and the careful monitoring of Derwent penguin numbers, will tell.

 

Striated pardalotes arrive early

The frost sparkled on the lawn, winter refusing to loosen its grip. Still, the song of spring rang out from the hedgerows in my valley and later from the woodland of the Waterworks Reserve.

The first of the summer migrants, the striated pardalote, had arrived.

In recent years I have been hearing the pardalote’s “pick it up, pick it up” song earlier and earlier. In the 17 years I have lived in the Waterworks Valley I have always timed it for the final week of August, just about a week before the welcome swallows arrive.

Last year, however, the pardalotes could be heard calling in mid-August and this month they beat this arrival date by about two weeks – August 1 to be precise.

Following a mild autumn, which also saw a lack of rain, I was surprised to hear the pardalotes still calling at the official start of winter and when I first heard a bird on August 1 I thought it might have been one of these stragglers, an individual perhaps somehow missing the migration north and deciding to tough out the Tasmanian winter.

The sheer number of birds calling, though, especially at the Waterworks Reserve, indicated that a wave of birds had arrived overnight, under clear star-lit skies, carried by favourable winds from the north.

Birds of many migratory species can take advantage of such conditions and a calling fan-tailed cuckoo, another early bird of summer, confirmed there had been an overnight flight of note.

The striated pardalote, one of three members of the family found in Tasmania but the only one to undertake migration to the mainland, is a cavity nester and uses the cracks between the sandstone walls of the Waterworks Reserve to house its nests.

Later I checked nesting hollows used year after year but they appeared to be devoid of birds. These early arrivals were merely possibly passing through my neighbourhood and heading further south.

Although it might have been the first day of August, with a month still to go before the official end of winter, spring was definitely in the air.

The reserve was alive with birds and birdsong, and a pair of masked lapwings were in a merry courtship dance.

Males of two species of robin, the scarlet and the dusky, were already staking out nesting territories. A particularly resplendent scarlet robin wooed a female with his descending tinkle of a song, a thin sound that seems to drip from the branches of the eucalypts like the morning dew before it is burned off by the sun. On a neighbouring branch, the female cocked an ear.

As birds arrive from the mainland on a north-south trajectory they cross paths with domestic migrants travelling east to west, leaving coastal areas that remain relatively warm in winter and heading to higher ground.

The reserve was alive with two such domestic travellers, eastern spinebills and crescent honeyeaters, dipping into the blooms of winter flowing grevilleas, marking time, refuelling before tackling the slopes of kunanyi/Mt Wellington towering above them.

Humble coot turns heads

About five years ago I added a new species to my bird sightings at the Waterworks Reserve in South Hobart – the humble coot.

Because the Eurasian coot was so familiar during my youth in Britain more than half a century ago I never paid them much attention when I first saw them in Australia. But to see them at my local reserve for the first time was notable, especially as one pair raised chicks that first year.

I now learn from the 2017 Tasmanian Bird Report – a marvellous journal recording what’s been happening in the avian world across Tasmania in the previous year –  that what I had seen was indeed a rare event.

On top of that I have discovered coots are migratory, flying considerable distances by night.

The revelation about coot nesting comes from contributors to the bird report, William Davis and Peter Brown, and their article also contains much fascinating reading about these members of the rail family, not least a detailed history of their movements and breeding attempts in Tasmania over the years from when they were first discovered rearing young here, in 1909.

They were not recorded breeding again until the early 1970s and in twos and threes they have been sighted nesting sporadically ever since.

One of the early observations about coots came from my illustrious predecessor, Michael Sharland, who wrote about nature in the Mercury under the  pseudonym of the “Peregrine” for 60 years before he retired in the 1980s.

In 1960 Sharland wrote that coot’s eggs were prized by avid egg collectors in the early 20th century because they were so rare. He also commented on the migratory habits of the coots, including an instance when thousands of birds synchronised their departure from Tasmania in 1956.

Despite these mass migrations at times, the travels of the coots is described as dispersive without regular seasonal patterns of moment.  Their breeding is also irregular, although as the observers at the Waterworks Reserve noted, the breeding in Tasmania follows the mainland nesting period from late September to December or early January.

Coots can be seen on virtually any stretch of open freshwater in Tasmania and are easily identified from the closely related and similarly-sized dusky moorhen by their round black bodies and white face masks.

Although I now learn they are strong fliers, they usually appear reluctant to take to the wing, merely running across the surface of rivers and lakes, beating their wings rapidly and splashing the water with their large splayed feet.

As soon as I read the coot article I went down to the Waterworks Reserve to check on the coots. Two birds were in a courtship display so hopefully I will once again later this year or early next see their fluffy jet-black chicks pestering the parents for food.

And if I am a little less tardy about recording sightings on the BirdlIfe Tasmania data base  we might be a little closer to solving what Sharland  described 57 years ago as the “Tasmanian coot mystery”.

 

 

 

Chaotic world belonging to man and beast

Handsome, striking; a male peregrine falcon, the fastest creature known to nature, perched amid the tangle and chaos of the human world, sitting atop a lamp tower on the Tasman Bridge.

He sits upright, jerking his head about him. Looking up, looking down, his eyes following the flight of starlings arrowing towards their winter night roosts on the bridge’s concrete spans. They are returning at day’s end from feeding forays into the country.

The starlings know the peregrine will be waiting, timing his arrival at the bridge at precisely the time of theirs: between 4.30pm and sunset at 5.07pm.

Flying in tight formations, swaying and gyrating like a swam of insects to confuse the falcon, they try to deny him a single target to strike and pluck from the sky.  During his swoop, or stoop, the peregrine will be capable of reaching speeds of up to 300 kilometres an hour.

The spectacle of peregrine falcons hunting starlings on the Tasman Bridge is well known to birdwatchers. In the past, parties of birders visiting from the mainland have even been moved on by the police, the officers worried the gawking and pointing from the raised footpaths on each side of the bridge might distract motorists.

Seasoned peregrine watchers, however, know the best vantage points are the car parks on each side of the river, which sit where the old floating bridge that was the forerunner of the modern structure were anchored.

Here the dashing flight of the anchor-shaped peregrine can be seen in the context of an open sky framed by the Southern Ocean to the south and hills and mountains to the east, west and north.

The night I arrive the peregrine fails to show at first. I know he is about. A friend who photographs ships sliding through the bridge’s spans has reported a sighting the night before. I wait, and am about to depart as it gets dark, thinking I’ve missed him. Suddenly there he is. He’s a beauty, a perfect, well-groomed male. Silver feathers on the breast, flecked with grey, slate-blue back and black “moustaches” running down his face, to absorb glare if he hunts into the sun at mid-day.

It’s a surreal moment at dusk; theatre in the spotlight of the bridge’s lights just coming to life in time for the evening rush hour.  The whirr of traffic, the steady rhythm of tyre on tarmacadam, the soft, long whistle uttered by starlings as they come in to land, as though calling to clan members to move over and make room for them on the crowded concrete terraces under the bridge, above the rippled waters of the River Derwent.

A groove has been cut in the black surface of the river by the wake of a fur seal, and as a flipper breaks the surface this flashes yellow in the beam of the bridge’s lights.  An oystercatcher pipes its staccato song as its flies fast and direct across the water’s surface, another reminder this chaotic, noisy world belongs to both man and beast.

But at dusk, it belongs most of all to the regal peregrine.

 

No dark wings and dark words here

My television birdwatching has reached new heights in recent weeks with the return of Game of Thrones.

To be honest, I’m more of a Breaking Bad and Better Call Saul viewer myself with a little “Nordic noir” thrown in, and I had so far resisted the demands of my family to make each episode of the fantasy saga a family experience.

That was until I heard the cry of a raven. My ears pricked up and I was hooked.

By some remarkable coincidence – although in my experience, coincidence and the mysterious seems to fly with ravens – I was at the time reading of research in Sweden which has put raven intelligence on a new level. It has been established for the first time that the European raven has the power to think ahead, an ability previously documented in only humans and great apes.

I’ve fed the only members of the raven and crow family found in Tasmania – forest ravens – in my garden over many years and seen behaviour which demonstrates they do some planning for the future instead of just acting on natural urges. They commonly hoard food, carrying off the scraps I put out for them to a hiding place.

But the ravens in a research program conducted by scientists at Lund University in southern Sweden have also shown they can actually plan ahead by setting aside for later a tool they know will get them a tasty treat. According to reports on the research, the ravens also bartered with both humans and other ravens for food, swapping a favoured blue plastic bottle top which they used as a toy, for a treat.

Although the evidence is new, ravens have long been associated with powers of foresight.

The series of epic fantasy novels, A Song of Ice and Fire, adapted into the Game of Thrones episodes, makes frequent use of crows and ravens as predicting things to come, and as messengers. The foundation of the stories, plots and characters also draw heavily from real-world mythologies.

Ravens feature in every known ancient myth. The Chinese, Egyptian, Greek, Semitic and Siberian legends depict the raven as a messenger of storms or bad weather. In African, Asian and European legends, the raven is an omen of death. In middle-European lore, ravens were often used as exponents of evil (for example in Shakespeare’s Julius Caesar, Macbeth and Othello). In contrast, Norse mythology puts ravens in a place of power and worship, often associated with the god Odin.

Many theories and parallels have been drawn between Norse mythology and the storylines in A Song of Ice and Fire, although there is a common idiom in the story that refers to ravens as omens of something bad. The creator of the original work, George R.R. Martin, no doubt saw ravens as symbols for death, tragedy or misfortune but when I view forest ravens in my garden I can’t see those “dark wings and dark words” as portrayed in the story.

Wader counts make sobering reading

Each year birdwatchers in Tasmania set out to monitor populations of migratory shorebirds – and each year they record staggering declines in numbers of these remarkable birds.

BirdLife Tasmania has in fact the longest data sets of shorebird numbers stretching back more than 40 years. These figures make sobering reading.

One species of the group of birds commonly called waders, the curlew sandpiper, is hardly ever recorded in Tasmania these days, after being counted in the thousands just a few years ago. And another, the eastern curlew, has decreased by 95 percent and is now listed as critically endangered.

There are, in fact, two wader counts in Tasmania, at the height of summer when the migratory wading birds have arrived from their breeding grounds in the northern hemisphere, and another in winter. The latter is designed to record what waders might be overwintering in Tasmania – mainly juveniles – and numbers of the non-migratory species like pied and sooty oystercatchers.

As usual in mid-July I took telescope, binoculars and pen and paper to the coastline around Dodges Ferry to play my part in the bird winter census which covers all of Tasmania’s mudflats and wetlands.

I wasn’t that hopeful of seeing eastern curlews – the biggest and most dramatic wader standing 66 cm tall, with an impossibly long down-curved bill – which are rare in winter at the best of times.

The curlews once flew in such great number across southern Tasmania in summer that they were shot for the pot in their thousands around Sorrell.

The decline in migratory shorebirds is largely attributed to vanishing wetlands along their migratory route, the Australasian-East Asia Flyway, which crosses some of the most densely-populated areas of the world where massive land reclamation schemes have taken place, particularly around the shores of the Yellow Sea.

Another threat to the waders is the draining of wetlands along the coast of Australia itself.

As the great northern migration was getting underway earlier in the year, conservationists lost the first round of a fight to halt a proposed development at a vital feeding ground in Queensland.

BirdLife Australia, of which the Tasmanian group is an affiliate, has long campaigned against the port and marina development at Toondah Harbour in Moreton Bay but federal Minister for the Environment Josh Frydenberg announced he was allowing the proponents, the Walker Group, to carry out an environmental impact assessment.

BirdLife Australia has in the past pointed out that Moreton Bay embraces wetlands which have international conservation status, falling under the United Nations-backed Ramsar convention on wetlands adopted in the Iranian city of the same name in 1971.

The ornithological organisation remains hopeful the Walker Group plan will be rejected for the same environmental reasons that scuttled its controversial proposal for a marina on Ralphs Bay in the Derwent some years back.  Conservationists had pointed out the bay off Lauderdale was vital to not only shorebirds but endemic marine life.

Meantime, BirdLife Tasmania members are assessing the results of the summer and winter surveys and so far they do not make happy reading.

Numbers holding but gulls not in good shape

Standing at the summit of the Glenorchy tip to the north of Hobart with grey clouds over the mountain threatening snow, it occurred to me there was a downside to birding.

Once upon a time it was enough to just watch birds, and revel in the beauty of their plumage and sweet melodies. Now it’s incumbent on the birder to also engage in citizen science to record bird numbers, especially of the many species decreasing in population across the country.

So on a winter’s day here I was on the Glenorchy tip, facing into a chilly wind with not enough power in it to carry the smell of rotting rubbish away from my nostrils

Species of kelp and silver gulls were having a fine old time, however, along with forest ravens.

Despite my discomfort, I wasn’t complaining. I was doing my bit, making a difference even if the subject of this project – gulls – might not be at the forefront of the fight to save birds in general.

Gulls occupy a niche in conservation science which is not only about vanishing species but also about how birds can be a pointer to the health of an environment which also embraces humans. Not only can they indicate poisons, like lead, on land and in water they can also mirror the health of the people with whom they share the habitat of city and suburbia.

Gulls tend to share the same unhealthy fast-food and, as I have written in the past, research in recent years into the health of city gulls has taught us that they are afflicted by very much the same health issues that city-dwelling humans are. Namely, they are obese from a lazy lifestyle in which they do not have to travel far for food, and as a result they have dangerous levels of cholesterol and glucose in their systems.

Perhaps more than any other group of citizen, birdwatchers are ideal candidates for citizen science because their hobby involves noting and counting bird species.  Now, instead of merely compiling lists of birds for checklists of species spotted, birdwatchers are increasingly monitoring bird populations on their home patches for a data base compiled by the national bird organisation, BirdLife Australia.

Clutching my clipboard at the Glenorchy tip, I attracted as much attention from people arriving to dump their rubbish one Sunday morning as I did from the gulls.

Out of the three species of gulls found in Tasmania kelp gulls were clearly the majority at the tip, about 300 of them flying around, and I was tasked with  separating the species into groups incorporating black-and-white adults, juveniles aged between two and four years in “salt and pepper” plumage, and first-year birds which are mainly clothed in brown. Silver gulls, were easier: there were only about 10 of these and none of the third species of gull found in Tasmania, the Pacific gull, which prefers a marine environment.

Comparing surveys over the years, BirdLife Tasmania, the local affiliate of the national ornithological organisation, reports gull numbers in Tasmania are holding their own, But that’s not to say they are in good health.

Raptors face rat-poison peril

A few years ago a bird of prey feared by my neighbourhood songsters stopped visiting my garden and I had my suspicions as to the reason why.

At the time wildlife biologist Nick Mooney was warning that a new range of anticoagulant rodenticides were taking a toll on birds of prey.

Mooney said that a more powerful second generation of the rodenticides which hit with a single dose had replaced a slow-acting earlier version. Both the rodenticides were still on the market, and still are, and Mooney urged farmers and gardeners with raptors on their properties to consider the earlier versions, which ultimately still did the job of killing rats and mice but did not have the same potency to immediately kill birds.

Mooney’s warning struck a chord with me because not only was I long longer hearing the chattering alarm calls of my resident new holland honeyeaters, I had noticed a spate of chicken coops springing up in the extensive gardens of properties in my peri-urban neighbourhood. I surmised that this surge in backyard farming had prompted a surge in rodents, and thus the application of rodenticides.

Mooney is again drawing attention to the menace of these powerful rodenticides, as we approach spring when rat and mice populations are on the rise.

Mooney has written a paper on the issue for the annual Tasmanian Bird Report, soon to be published by BirdLife Tasmania.

Mooney, however, is not pointing a finger at gardeners wanting to protect their chicks, eggs and crops, but merely suggesting an alternative strategy that is less dangerous to birds and indeed native mammals.

The less harmful rodenticides with warfarin or coumatetralyl as the active ingredient carry the trademark of Ratsak Double Strength and Racumin.  Those more dangerous to birds are Talon and Ratsak Fast Action.

Mooney also points out there are alternatives to anticoagulants which are harmless to birds.

 

 

 

In his paper, Mooney gives details of bird species confirmed by necropsy to have been killed by the poisons. Especially at risk are masked owls, 11 dying in the Hobart area in recent years, including one recovered from Salamanca Place.

Mooney points out this number is probably only the tip of the iceberg.  The vast majority of the masked owl population occurs in rural landscapes inter-dispersed with patches of dry woodland, villages and towns. Excluding the woodland, Mooney estimates that about two-thirds of the estimated population of a little less than 1000 birds of the rare and threatened owl could be exposed to the second-generation rodenticides. Of these, Mooney estimates that 10 per cent, or 100 birds annually, could be killed.

Other birds listed as being killed by the powerful rodenticides include boobook owls, white goshawks and the brown goshawks of my garden.

When Mooney first raised the issue I wrote about it extensively and spoke to hobby farmers in my home valley in Hobart where suburbia meets bush who might be using the poisons.

I am pleased to report that in recent years the brown goshawk, and a smaller goshawk, the collared sparrowhawk, have returned, much to the annoyance of the honeyeaters.