July 28, 2017

A column for all seasons

Everyone has a story about birds. They are all about us and are our contact point with nature. The birds I see are usually in an urban environment and so I concentrate on these in my writing. I don’t pretend to be an expert but birds of the city and suburb are also the ones that most people identify with, the species you do not need a compass and binoculars to seek out. A scarlet robin singing in a garden is just as exiting as a swift parrot in an ancient forest and is worth just as many words in my On the Wing writings.

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.

Yellowthroat struts the stage

Right on cue, like an actor strutting the stage, a striking male yellow-throated honeyeater made his presence felt in the Waterworks Reserve.

With the first snows of winter settling on kunanyi/Mt Wellington , the honeyeater always lays claim to a patch of exotic winter-flowering vegetation and he takes on all comers.

The flowers of the “Ned Kelly” grevillea are a vital food source in the winter months and they are eyed enviously by other members of the honeyeater family visiting the reserve.

Male yellowthroats defend mating territories year-round and after the breeding season the bird I’m familiar with appears to extend his range to include a flower bed in the centre of the reserve, framing a children’s playground.

The yellowthroat is happy to tolerate the children coming to play, but gives crescent honeyeaters and eastern spinebills short shrift.

The crescent honeyeaters and spinebills come down from their summer breeding territories on the mountain to establish winter ranges closer to the coast. All winter long they engage in skirmishes with yellowthroats. The crescent honeyeaters generally come off worse – being chased off without getting a feed – but the spinebills use their smaller size and aerial dexterity to nip in to steal a quick sip of nectar.

The spinebills, with long scimitar bills as their name suggests, are the “pick-pockets” of the bird world, stealing food before the yellowthroats realise what is going on.

Throughout the Hobart suburbs these jousts take place during the winter months.  In gardens that do not have the tall native trees favoured by the yellowthroats – from which they glean insect food if they are not feeding on food produced by flowers – the wars in the grevilleas and bottlebrushes usually take place between resident New Holland honeyeaters and the crescent honeyeater and spinebill raiders.

My interest though in the autumn and winter months is concentrated on the yellowthroats. I find them stunningly beautiful birds and it is no surprise that when BirdLife Tasmania was founded it was decided to choose an image of the species as the organisation’s official emblem. BirdLife Tasmania’s newsletter is, in fact, called The Yellowthroat, but many Tasmanians unfamiliar with birds are unaware of its existence.

Because it often hides in the canopy of tall eucalypts  the yellowthroat escapes our notice, although its familiar song,  which I can only describe as a rapid-fire “chortle”, rings through the leafier suburbs.

The yellow-throated honeyeater is a medium-sized honeyeater with a relatively long tail. The average length is 21 cm.[2] The plumage is bright olive green above, with a silver-grey crown, face, and underbelly contrasting with a distinctive bright yellow chin and throat. Females, which are smaller than males, are duller in colour.

The yellowthroat is only found in Tasmania – one of 12 species endemic to these islands –  and so is much sought-after by mainland birdwatchers wanting to add to their Australian checklists of birds spotted.

It may often slip under the radar in its home state, but the large number of visiting birdwatchers to be found searching for it at the Waterworks Reserve in the spring and summer months are evidence that its reputation has spread far and wide.

Website: Donldknowler.com






Dark Mofo enters the soundscape

The duel of the decibels – the chorus at dusk when birds try to outdo each other to dominate the air waves as light fades – was particularly vocal one mid-winter evening.

The clinking of currawong, the caw of raven and the trilling of new Holland honeyeater was in competition with another, alien sound.

As I walked the streets of South Hobart, I had forgotten that the Dark Mofo winter festival was about to start, even though the night before I had seen city buildings and the Tasman Bridge already bathed in the festival’s signature red light.

A feature of the 2017 festival had been billed the Siren Song, in which at dawn and dusk unconventional sounds would be broadcast across the city from 450 public address speakers placed atop buildings around the waterfront.

According to the pre-festival blurb, what I can only describe as the sonic version of installation art would be heard from up to two kilometres away, and here I was, double that distance, being bombarded by sound on two fronts. The birds, particularly the forest ravens for some reason, were responding in kind. It was surreal and unnerving.

The festival organisers described Siren Song as exploring “sound as an expression of patriarchal power and authoritarian control … and in turn, how sonic tools used to control and communicate might give voice to beauty and abstraction”.

For me, its timing at dawn and dusk over 10 days tapped into something far deeper than a celebration of sound in all its forms.

The Dark Mofo festival delves into centuries-old winter solstice rituals, exploring the links between ancient and contemporary mythology, humans and nature, religious and secular traditions, darkness and light, and birth, death and renewal.

Humans claim such rituals as their own, but the division of light and dark has been recognised since long before Homo sapiens entered the frame.

The dawn and dusk chorus is nature’s clock, telling the creatures of the wild when to wake and when to sleep, although for nocturnal creatures the sequence is reversed.

With the parameters of day and night cemented in their genes, birds sing loudly at dawn to re-establish bonds and declare territories. And at dusk, they call each other to night roosts, often gathering together for safety in numbers. At no other time of the day are they so vocal.

Birdsong is so important, so vital to birds, that those living in our cities across the globe have been found to be moderating their songs to take into account the loud sounds of the human world, particularly motor traffic.

Blue and great tits in European cities, for instance, sing louder than their counterparts in the country, as I have discovered myself in London.

Birds that use mimicry to enhance their repertoires are also increasingly using sounds from the human world, with lyrebirds now mimicking chain-saws.

I suspect, though, the birds of South Hobart were pleased to welcome the relative silence when Dark Mofo was over and were cocking their ears in a different direction.

Cuckoo reluctant to leave

The far-carrying, trilling call of a fan-tailed cuckoo rang out across the Waterworks Valley. It’s a constant refrain in the summer months but this was at the start of winter.

Was it a fan-tail choosing to make an ultra-late departure for its wintering grounds on the mainland or one choosing to take its chances and brave the Tasmanian winter.

Certainly a cold snap earlier in the month of May had given the cuckoo every incentive to leave.

It’s not the first time I have heard a fan-tailed cuckoo in winter, and indeed the fan-tails were the first of the migrants to arrive in my home valley ahead of spring last year,  beating another early arrival, the striated pardalote, by a few days in the last week of winter.

The fan-tail is one of four species of cuckoo (there are 17 Australian family members) to visit Tasmania, the others being the pallid and shining and Horsefield’s bronze-cuckoos.

The fan-tail appears to be the most common, certainly in my valley, and I must confess I feel a sense of relief when its stops singing along with the others at the end of the breeding season at the end of February.

I’m not a fan of cuckoos, especially the fan-tail, which because of its intermediate size is able to exploit a whole range of nests, from the dome, forest-floor constructions of the fairy-wrens to the open, tiny cup nests of the pink robins hidden in dogwood.

Every time I hear their calls and songs I know the cuckoos’ anti-social work is at play. They out-source parenting, of course, laying a single egg in the nests of other birds.

The cuckoo chick grows rapidly, using its large yellow-gaped beak to demand an uneven delivery of food normally shared through a brood. Then the cuckoo chick manoeuvres its body to eject its “siblings” from the nest, or merely suffocates them below its larger body.

As if the thought of that is not bad enough, the most disheartening sight to my eyes is seeing the harried parents feeding the outsized chick. Last summer I saw a pair of black-headed honeyeaters flying to and fro to a belligerent pallid cuckoo chick, the honeyeaters only about a third of the cuckoo’s size.

By coincidence, a day after hearing the calling cuckoo I read an account in a British newspaper expressing joy at the arrival of the first cuckoo of spring.

The cruel European winter cannot really be considered to be over until the onomatopoeic call of the European cuckoo – the only species to visit Britain – is heard, and for more than a hundred years there has been a tradition of readers of The Times of London announcing its arrival on the newspaper’s letters  page.

The cuckoo, however, has carried a more sombre message in recent years. Cuckoos are increasingly failing to arrive from their wintering grounds in Africa, the clearing of native woodland and drought thought to be the reason.

So when the cuckoo calls, Britons can be forgiven for putting its anti-social behaviour at the back of their minds.

Students tackle lorikeet menace

A group of students from Hobart College certainly demonstrated they were out to make a difference at a World Environment Day event earlier this month.

Their “A Fair Go for Swifties” presentation attracted a big crowd at the Hobart Sustainability Learning Centre, during which the students laid out plans for not only monitoring populations of the critically-endangered swift parrot but an invasive bird species, the rainbow lorikeet

More than 80 students at the college have this year volunteered for the Student Environment Team (SET) and, after first tackling such green initiatives as Clean Up Australia Day, the teenagers have settled on their most ambitious project to date.

With the parrot project they are fortunate to be working with a conservation biologist from the Australian National University, Dr Dejan Stojanovic, who is leading the campaign to save the swift parrot and devising ways to keep numbers of the introduced rainbow lorikeet under control.

Dr Stojanovic is training the SET team members to be effective citizen scientists, working towards a paper on the collaborative results gained from their research. Hobart College has been awarded two grants to help with the Fair Go for Swifties Unwanted Rainbow Lorikeets Project. The largest, from Natural Resource Management South, provides $7000 to assist with building more than 50 rainbow lorikeet nesting boxes and developing data bases and technology equipment to make accurate field observations.

The college’s Information technology students gave presentations during World Environment Day on how members of the public could contribute to the data bases and also showed examples of the specially-designed nesting boxes they have designed to aid parrot nesting success.

Nest boxes have also been designed to trap rainbow lorikeets – which compete with swift parrots for nesting cavities – so they can be destroyed humanely.

Dr Stojanovic said during the event the rainbow lorikeet, which is native to south-eastern and eastern Australia, could also pose a serious problem to farmers and fruit growers if left unchecked.

The researcher said the lorikeets had already caused serious problems in Western Australia, where they had also been introduced.

Dr Stojanovic said that he is concerned that the same scenario might play out in Tasmania.

“We’re quite worried that in Tasmania they might have a quite serious impact on the grapes and the fruit growing industries that occur around the areas where they now live,” he said.

The rainbow lorikeet – a beautiful parrot which as its names suggests incorporates the colours of the rainbow in its plumage – is mainly confined to the Kingston area at present but it is slowly extending its range. There is another isolated population in the north-west of the state.

Another concern is that the rainbow lorikeet might interbreed with a closely-related parrot which occurs naturally in Tasmania, the musk lorikeet. Already hybrid birds are being seen in the greater Hobart area.

Dr Stojanovic said that while the lorikeet population is small, the best strategy is eradication rather than containment

“At this stage, since it’s early in the invasion process, eradication is a real possibility,” he said.

Dr Stojanovic said that while the lorikeet population was small, the best strategy was  eradication rather than containment.

Birds unite people across the globe

No two places have the same birds and that, partly, is the magic of birdwatching. Travel short distances and the birds change, as do the people who watch and study them. Birds are not merely inspiring creatures, filling us with wonder and awe as we observe them in our gardens or contemplate their remarkable trans-continental journeys. Their global presence gives birds the power to unite people across the globe in appreciation of their beauty. They bring birders together across cultures, languages, and international borders. 

The worldwide interest in birds is now celebrated by an event called the Global Big Bird Day in which teams of birders across six continents compete over 24 hours to see who can see the most species

On May 13 this year, almost 20,000 birders from 150 countries around the world joined together as a global team, contributing more than 50,000 checklists containing 6564 species—more than 60 per cent of the world’s birds. This is a new record for the number of bird species reported in a single day from the time the competition was started three years ago.

Four countries topped 1000 species for the tally: Brazil, Ecuador, Peru, and Colombia. In past years Brazil and Peru had always vied for the Number 1 slot but in 2017 there was a new champion: Colombia.

With 1486 species on a single day, the organisation of the Colombia team was impressive, reporting almost 2500 complete checklists—and close to 15 per cent of the world’s birds. Peru (1338 species), Ecuador (1259), and Brazil (1079) were not far behind.

The contest is skewed, of course, because some countries have more species than others, but it is also possible to give countries ratings on the percentage of birds they found out of their national total.

On this score, Australia fared well. This year’s 487 species – out of a national total of about 900 – came from about 350 people, covering all states from Tasmania to the Top End. Tasmania – with just 350 species – was never in the running for the top score within Australia. This was achieved in Queensland where 144 species were tallied on the day but Tasmania stood out in the tally – more endemic species recorded than anywhere else.

What it lacks in number Tasmania makes up with its 12 species found nowhere else on earth – plus the critically endangered, migratory orange-bellied and swift parrots – and these are attracting increasing numbers of both mainland and international birders to these shores.

The hobby of birdwatching is booming worldwide and with it an associated spending on equipment and travel. The United States Fish and Wildlife Service estimates there are 46 million American birdwatchers, putting US$46m into the economy, including on travel. A Caribbean Tourism Organisation survey estimates at least three million tourists travelling the globe have birds in their sights, and West Indian nations are mounting campaigns to attract them to their islands.

The Global Big Bird Day plugs into this growing interest in birdwatching and countries and states with unique birds, like Tasmania, are in a perfect position to obtain a slice of the birding pie.

Autumn in its glory

The metallic “eg-ypt, eg-ypt”  contact call of the crescent honeyeater and the descending rapid twitter of the eastern spinebill might announce in my garden the arrival of autumn and winter, but as a Pom I long for another sign of the changing seasons. That is the vivid colours of the dying leaves on deciduous trees as they turn from green in summer to autumnal shades of red and gold.

To get my autumn tree “fix” I usually stroll the streets of South Hobart which are lined with deciduous trees – the ancient Gingko biloba from China among them – or Hobart’s city parks which have arrays of classic English trees, including oaks, elms and silver birches.

This year, however, I decided to venture further field to track down a deciduous tree not of Europe but unique to Tasmania – the legendary Tasmanian fagus (Nothofagus gunnii).

My quest would take me to the Mount Field National Park and as an added bonus to my autumnal tree hunt there would be birds aplenty, species which make the mountains of Tasmania their home.

As far as birds go, my first steps more than 1000 metres high up in the park were greeted by the pleasant melody of a bird found only in Tasmania, the Tasmanian thornbill and coming out of the mist on higher slopes above Lake Fenton – where I had been told I would find the fagus – came the far-carrying trumpet call of the black currawong, another bird only found on these islands.

But this trip was primarily to be about the fagus, or Tasmanian beech, and I was not to be disappointed. Despite the passion it arouses among botanists – and those like myself who love to witness “the fall” as North Americans describe the autumn leaf-change – the Tasmanian fagus is a humble tree, only growing to a height of about two metres. It is usually found in places best described as inhospitable. It is also called tanglefoot, a name bestowed on it by pioneers and now bushwalkers, caught up in its twisted, ground-hugging branches.

The tree, dating from the ancient continent of Gondwana, is notable for its tiny leaves which in summer are a beautiful lush green but in autumn change to rust or the colour of honey before dropping to the ground. The leaves are rounded and have a grooved crinkle-cut pattern on their surface.

I thought, with such a low aspect and tiny leaves, the fargus might take some finding high up on Mt Field but the plant stopped me in my tracks as soon as I had reached the car park at the lake. The sides of a boulder-strewn hill climbing to the mountain peak were wreathed in spectacular colour, matching the grey tones of the dolerite rocks and the blue-green of the surrounding snow gums and king billy pines.

Timing has to be just right to catch the beech in its full glory. Fagus turns its spectacular range of colours during late April and into May, depending on the temperature in the previous month. I was lucky to catch it at its peak, in the second week of May.



Black cockatoos herald winter

Turning over the page of my Australian Geographic wall calendar on May Day a picture of a pair of my favourite birds – yellow-tailed black cockatoos – announced the approach of winter.

Although in fact the calendar said we were starting the last month of autumn, the coming of winter was confirmed a day later when I saw the first snow of the year on kunanyi/Mt Wellington.

The May page of the calendar was adorned with a hand-coloured lino-cut by wildlife artist Vida Pearson, which showed the cockies munching on the flower cones of silver banksia.

The picture depicted a scene in the Grampian Mountains of Victoria but it could have been inspired by events in Tasmania because two cockies I saw next day were also making the most of a crop of banksia flowers in a low bush at the start of the Pipeline Track near my home in the Waterworks Valley.

After munching on the banksia cones, the pair of cockies flew to a dead gum, where they then proceeded to probe the bark for wood-boring grubs.

It was unusual to see just a pair of cockies at this time of year because I usually see them with a youngster – the juvenile noisily calling for food – or in loose flocks of up to 20 birds with young birds flying with them.

The cockatoos lay two eggs but one bird only usually survives, to stay with his or her parents right through to the next breeding season.

I didn’t want to dwell on what might have happened to the cockie pair’s chick, instead I spent an enjoyable half hour or so watching them at work in the dead gum. The female – identified by her whitish beak, whereas the male as a black one – watched on approvingly from a higher branch as the male pressed his ear to the trunk of the tree to listen for the movement of the grubs under the bark. When he heard one, he tore at the fibrous wood furiously, using his powerful beak to send strips of bark to the forest floor.

Although Tasmanian folklore suggests the arrival of cockies in towns and cities foretells bad weather, the black cockies move to lower terrain in any case during winter. But the first snow of winter no doubt spurs this movement.

Cockies seek out ageing trees in spring which provide nest hollows – these are mainly found on the mountain in the Hobart area – and they spend the summer there feeding on the rich bounty of pollen and nectar produced by shrubs and trees. As autumn bites, they take young down to lower slopes in search of burrowing insects in dead bark, or the blooms of silver banksia which flower during autumn and into winter.  On the mainland, black cockies are known to forsake the high country for bottlebrush woodlands on the coast.

In the Waterworks Valley, the black cockies seem content to spend the winter there and when frost lies thick on my lawn they are welcome visitors to my garden.





Swift parrots lose a favourite tree

While swift parrots have been darting through the great ironbark forests in their wintering grounds in Victoria and southern New South Wales this autumn one of their favourite trees in Tasmania has fallen victim to the chain saw.

Letter writers to the Mercury have lamented the loss of a giant blue gum in the grounds of the Anglesea Barracks in Hobart.

Although there appears to be nothing untoward or underhand in the destruction of this towering tree – it had succumbed to old age and was considered dangerous to passers-by at its location at the junction of Molle and Davey Streets –  it certainly has left a gaping hole in the sylvan fabric of the city.

The Anglesea Barracks is noted for several blue gums which were growing when the military base was first established in the early 1800s but as far as I can establish the tree in question was not on Hobart’s significant tree register, like some of the others.

Nonetheless, it was a fine specimen of Eucalyptus globulus and in spring I always made a point of visiting it when it was in flower, in the hope of seeing swift parrots feeding in its white blooms.

It had not always been a happy hunting ground for this critically-endangered species, however.  One year I found a dead swift parrot on Molle St, the bird presumably falling victim to traffic when it was in swift but low flight.

Swift parrots tend to congregate in our cities and suburbs in spring – when not just eucalypts but introduced exotic trees are in flower – before heading out to the remaining blue gum forests along the east and south-east coast. At this time swift parrots are especially vulnerable to hitting cars or windows in suburban areas.

I’ve never forgotten an account of swift parrot carnage, when a bird researcher told me of at least 10 swift parrots being killed by a truck as they darted across Rosny Hill Rd on the eastern shore, travelling from the golf course bordering the highway to blue gums on Rosny Hill.

The swift parrots’ very existence is tied to the glue gum which provides both food and nesting sites but the saga of the blue gum on Davey St has also revealed that the people of Hobart love their blue gums as much as the swift parrots do.  The felling of the tree has attracted many posts on Twitter, one from biologist and author Tim Low who mentioned this particular tree in his best-selling book, Where Song Began.

My primary interest might be in birds but comments in both the Mercury and Twitter about the lost tree in have struck a chord as powerfully as the parrot’s twittering song in spring.

As one reader wrote, describing the felling of another tree near her home in the vicinity of the barracks: “I remember the absence of the sound of the leaves– this I realised was the most upsetting part. Living a few houses away I could hear the space it left in the air – an uncomfortable silence.

“A city without large trees is a strange place to live in.”