Tim the Yowie Man: Mystery on the Monaro

During the last decade a significant swath of the Monaro has been devastated by a widespread form of dieback which has resulted in many of the area's gum trees, especially manna gums (eucalyptus viminalis) being defoliated and left standing like skeletons in a vast tree graveyard.

The affected area covers almost 2000 square kilometre (almost the size of the ACT) and extends from Cooma in the north to the outskirts of Jindabyne in the south and is clearly visible from the Monaro's busiest highways. The epicentre is near Berridale where in the paddocks and on the ridges extending to the horizon, it appears as if every tree is dead. The extent of the decimation has prompted many of this column's correspondents including George Parkinson of Kambah to comment "it looks some sort of war zone," and ask "what's causing it?"

Regular readers may recall that two years ago (Mystery Predator, May 1, 2013), this column ventured into the killing zone with student Catherine Ross who was attempting to solve the mystery as part of her science honours project at the Australian National University. Catherine revealed she had a long list of suspects to consider, including introduced pests, salinity, pollution or disease, agricultural practices (grazing, improved pastures, fertilisation, clearing), altered fire regimes, and climatic effects.

However, at the time, the prime suspect was the eucalyptus weevil (Gonipterus sp.), a small (no bigger than your fingernail) brown beetle which had been found in large numbers on the defoliated trees. Although the weevil is native to most parts of eastern Australia, where a local parasite helps control the population, it was thought that perhaps a genetically different species of the weevil had been introduced to the Monaro, one whose population couldn't be kept in check by the local parasite.

"However, it turned out that weevil was the local species after all, known as Gonipterus sp. no.2 (as yet undescribed)," explained Catherine earlier this week, adding, "it was no longer a suspect but merely the weapon, being wielded by a hidden hand."

Over the last two years Catherine has meticulously eliminated each of the other suspects leaving one likely culprit - climate change.

"The onset of the Monaro dieback coincided with one of the worst droughts on record, during which the average rainfall dropped from around 550mm to 450mm per year," says Catherine. "It seems that the climate has become drier and more variable, causing stress to trees and making them more susceptible to attack by the eucalyptus weevil."

Manna gums normally grow in much wetter areas, and their distribution is strongly related to rainfall, leaving Catherine to conclude that "the harsh climate of the Monaro was already on the edge of their range, and the recent changes may have pushed them beyond a critical threshold".

However, Catherine concedes that "much of the evidence is circumstantial, and further investigation will be required to uncover exactly how the changes in climate and the insect infestation are interacting to cause the dieback".

Meanwhile, consideration is being given as to how to revegetate the vast area affected. Catherine suggests that "one possible approach might be to replace the manna gums with another tree species that is better adapted to the new (and future) climatic conditions; for example a species that currently occurs in more arid areas to the north and west".

This strategy of ecosystem rehabilitation is known as "assisted migration" and is a controversial topic of debate amongecologists and land managers. "Introducing species always carries the risk of causing damage to the ecosystem, but in an already very degraded landscape the benefits may far outweigh the risks," says Catherine.

A face only a mother could love

"OK, Tim. I give up!" exclaims John Howard of O'Connor. "Chuck Young's terrified wife discovered an 'antechinus' in her sleeping bag when they camped at Mystery Bay (Dedicated to You, 3 January, 2015 Web link: http://www.canberratimes.com.au/act-news/tim-the-yowie-man-dedicated-to-you-dear-reader-20150102-12evsn.html ), Ugh! Please, please, Tim, what is an antechinus and what does it look like?" pleads John, adding, "I will not sleep soundly, until I know."

The brown antechinus (Antechinus stuartii) is a native species of small carnivorous marsupial, mainly found east of the Great Dividing Range in forested areas from south-eastern Queensland to the far south coast of NSW.

While Chuck (or his wife) was unable to photograph the said beast, using the light of his torch Chuck describes it "as around 70mm long, grey, and roughly three times the size of a mouse, adding "it was gorgeous, but this one was obviously terrified."

Meanwhile, Denis Wilson, this column's regular Southern Highland's correspondent recently snapped a photo of an antechinus after his neighbour heard "scrabbling noises" in his young son's wardrobe. "So we could take photos of it, we got it into a kitchen tidy with sides sufficiently high that it could not jump out," explains Denis who reports "from above it had a fine set of whiskers, a pointed nose and prominent eyes".

After all the hoopla, Denis' neighbour finally got his son back to sleep. And the antechinus? Well, it was safely moved outside to the family's (cat-free zone) backyard.

In the Spirit of Banjo

Almost three years ago while investigating the curious case of Devil's Seat (a rock in the shape of a throne) at Narrabundah's Rocky Knob park, I met the lovely June from adjoining Griffith. To show me what an avid reader of these pages she was, June, an octogenarian with impeccable manners, had brought along her collection of about 100 of these columns that she'd carefully torn out of Panorama and placed in a folder. Unfortunately, it was a particularly breezy day and as June opened the folder to show me the extent of her collection, a gust of wind sent many of them hurtling around the park and over fences. Apart from the one which ended up in a muddy puddle (I'm sure some might see as a fitting place for my weekly musings), after an hour of chasing papers into trees and down laneways, and over backyard fences, I think I managed to save most of June's collection.

At the time June politely suggested that it "would be more convenient to keep a record of past columns if they were available in a book format". I promptly agreed (you would too if you'd just come face-to jowl with a particularly ferocious-looking doberman in a stranger's backyard), promising that one day I'd take up her suggestion. Well, that day has finally come, this akubra-clad columnist has teamed up with Canberra-based publishers Pendragon Publishing & Design to produce In the Spirit of Banjo – the recent adventures of Tim the Yowie Man, a collection of my favourite adventures. The book is divided into sections covering Canberra as well as this column's other haunts including the south coast, snowy mountains and southern highlands.

One of the most common questions I'm asked (apart from when are you finally going to get rid of that old hat) is – "have you run out of material yet?" Far from it, I've only touched the tip of the iceberg, for every time I venture out, whether it be to some obscure swimming hole on the Snowy River, or a secret part of well known Canberra landmark, I invariably return with three or four more stories each worthy of a stand-alone column.

Over a quarter of a century ago, my high school headmaster, Rhodes Scholar, David Wright would regularly repeat his favourite motto, "you know you are educated when you know you know nothing." Every time he repeated this, I'd think that he had a few kangaroos loose in his top paddock. However, those words now ring loudly in my ears every time a reader of my column suggests a new mystery, a hidden location or a lost tale for me to investigate. In fact, the more I explore and write about this wonderful region, the more I realise just how little I know about it.

In the Spirit of Banjo will be launched this Monday, March 2, at 6pm at Smiths Alternative Bookstore, 76 Alinga St, Civic. If you'd like to attend this free event, please email: graphics@pendragondesign.com.au. I'd love to meet some of you there. Oh, and June I've misplaced your contact details, but if you bring along that bulging folder of yours (don't worry, it shouldn't be windy inside the bookstore), I'd be delighted to present you with a complimentary copy.

If you can't make the launch, but would still like to buy a copy of the book, it'll be available at Smiths Alternative Bookstore, Book Passion (1 Lathlain St, Belconnen) or the online bookshop at: www.pendragonpublishing.com.au

WHERE IN CANBERRA?

Cryptic Clue: One of a dozen under the gaze of a platypus

Degree of difficulty: Medium

Last week: Congratulations to Jacqueline Woodbury of Melba who correctly identified last week's photo (inset) as a part of the exterior of American artist James Turell's Within without in the Australia Garden at the National Gallery of Australia. "It's a favourite of mine with the ever changing light and beautiful reflections in the water," says Jacqueline, who adds, "his retrospective exhibition, currently showing, is definitely worth seeing."

Within without is the largest and most complex Skyspace created by Turrell. Light is Turrell's medium, and this extraordinary Skyspace is a viewing chamber that affects the way we perceive the sky – and everything in it, including the sun. It's open daily and free. During dawn and dusk there is a special light cycle sequence. Call for details: 02 6240 6411. Tim's Tip: Give yourself at least 40 minutes to experience this sensory extravaganza.

How to enter: Email your guess along with your name and address to timtheyowieman@bigpond.com. The first email sent after 10am Saturday February 28, with the correct answer wins a double pass to Dendy cinemas.