Bobucks in The Gurdies, near Grantville?
This page provides additional images of Bobucks in conjunction with a paper presented in The Victorian Naturalist : Presence of Bobucks (Trichosurus caninus) in The Gurdies on Westernport Bay, Victoria, D. Hynes and M. Cleeland, The Victorian Naturalist v122 (3) 2005, 141-145. Download a scanned PDF of the print article? Click here (PDF, 380K). The quality isn't A1: I'm still trying to combine high definition with a reasonable file size.

The location (Clickable Image) As described in the print article The Gurdies Nature Conservation Reserve is made up of 260 hectares situated on the eastern side of the Bass Highway at The Gurdies a few kilometres north of Grantville. The surrounding countryside was cleared in the 19th century and is mainly used for beef cattle grazing nowadays.

The camera site's GPS coordinates were 38° 22.865'S, 145° 33.420E. Grid coordinates on the National Map Series Warragul Sheet 8021 (1:100,000) were CT739509. The management authority responsible for upkeep of The Gurdies Nature Conservation Reserve is Parks Victoria South West Gippsland.

Description of the Area.
The Bobucks appear to inhabit a creek which demarcates the Donmix quarry lease from the Gurdies nature reserve. The creek is slow flowing and supports a dense stand of bulrushes. Whether the animals live in the creek itself or in the understorey contiguous with it is not certain at this stage. Tree hollows and fallen, hollow logs that mountain Bobucks typically use as dens appear to be few. The authors therefore suspect that these Bobucks utilise tunnels in the thick rushes as dens and refuges. The conjecture is not confirmed at this stage but if it turns out to be true, it is obviously very important to conserve the creek in its present state if this tiny yet remarkable population of animals is to survive.

Both cameras were set up on the margins of the creek, close to the water. Their exact situation may perhaps be described as the interface between dry ground and bracken understorey, punctuated by stringy bark gum trees, along with introduced plants and the swampy, reed choked creek.

Images Collected

This is the first picture ever taken of a Gurdies Bobuck, at night in its atypical, coastal swamp habitat. The image was captured during the nights of 18/8/2004 to 20/8/04. The broad, flat head, dark coat colour and short, rounded ears immediately defined it as something unusual. The weather on these nights was calm and reasonably dry and photographic conditions were good. (Clickable Image)

Bobucks in the creek by Donmix Cement's quarry.
Two cameras were deployed over the nights of 1//9/2004 to 3/9/2004. It rained heavily on the first night when these images were being taken. The cameras themselves are designed to function in almost any weather conditions. Rain, however, degrades the quality of images captured owing to water and mud splatter on the perspex window that protects the actual camera. The difficulty is that rain droplets lodged on the window reflect light from the camera's flash. The issue is being addressed in current versions of the cameras.

The following images are clickable to a hi-quality JPEG. These images are the first of their kind: the animals are representatives of a population unrecorded until now.

Diagnostic feature: the animals have "brush tails". So, definitely a "Brushtail Possum": but what sort? The Common Brushtail Possum (Trichosurus vulpecula)

One objective of this exercise was to answer a technical question: can automatic cameras distinguish between closely related and physically similar animal species? In order to make a (+) identification, it is necessary to be able to examine a specimen's "diagnostic" features in some detail. Can a robotic camera do this under "field conditions" - namely at night, in rain and/or temperatures below the dew point?

Bobucks, Trichosurus caninus, are similar in many ways to their cousins the Common Brushtail Possums, Trichosurus vulpecula. However, there are enough physical differences between the two that they are classified as separate species. Have the authors brought digital automatic photography to the point where small divergences can be discerned without the necessity for trapping the animals? In other words, can the cameras used in this exercise allow an observer to tell apart these two cousins?

In order to capture images with the necessary level of detail the camera must, obviously, be placed in close proximity to the subject. Since most Australian native animals are nocturnal in habit, operation at night is called for. These conditions are easy to specify but, until now, have been extremely difficult to implement "out there". So much so that professional wildlife photographers, using traditional methods of wildlife photography, have sometimes dismissed automatic photo traps as "a waste of time", Raithby & Beste (1971).

How can we be sure we have images of Bobucks?

Novel camera technology, developed by the authors, allows images of wild animals to be captured at close quarters in wilderness settings. But is it helpful for the purpose of identifying native fauna? For visual identification, the ears appear to be the most prominent distinguishing feature between T. caninus and T. vulpecula. The ears of T. vulpecula are longer, relatively more slender and pointed than those of T. caninus. T. vulpecula has a lighter coloured coat and has a brown stripe running vertically down its chest. This feature appears to be absent on T. caninus.

In the table below we align head & shoulders excerpts from the images of the provisionally identified Bobucks with images of Common Brushtail Possums. The cameras used in this exercise can capture very many images: several hundred archived pictures of Common Brushtails are available to choose from. Therefore, we select frames where a Brushtail Possum's posture, body size and distance from the camera match reasonably closely those of the proposed Bobuck images. Are they the same kind of animal or do the images from Westernport show a different species?

TABLE #1: Comparison of T. vulpecula with the Gurdies Animals

The Common Brushtail Possum - Trichosurus vulpeculaThe Gurdies Animals - are they Bobucks (Mountain Possums), Trichosurus caninus?

Other Animals Photographed.

A question of interest is - what animals do these Gurdies Bobucks share their habitat with? The cameras detected Bush Rats, Rattus fuscipes, for one. Doubtless there are other fauna about - foxes and feral cats certainly, probably swamp wallabies and other marsupials. A longer survey would give a more complete picture of the Bobucks' environment.

Conclusions and Discussion

The authors believe the animals here documented in The Gurdies may represent a relict that has been cut off from other population centres. How long they have been isolated is not clear at this time. Their absence from previous surveys, together with the sparseness of local lore about them or of sightings or captures in the district, suggests that The Gurdies population is extremely small.

The authors feel that this circumstance is quite remarkable. These animals apparently live only a few hundred metres from the main arterial highway into South West Gippsland and Philip Island, namely the Bass Highway, yet they have remained uncatalogued and virtually unobserved for who knows how long.

Bobucks are basically an alpine species. The photos show they have many physical adaptations that allow them to cope with the extreme cold they must endure above the snow line in the Victorian Alps over winter : short ears, large body size, dark colour, generally "stumpy" build. These are attributes commonly found in cold adapted species because they help minimise the loss of body heat.

Yet it is apparent these Gurdies Bobucks have learned to cope with an atypical, tree lined swampy habitat near the shore of Westernport Bay. Presumably they are confined to scattered "habitat islands" such as this creek. Where other such "islands" are to be found is not known at this time.

They would seem to represent an unusual adaptation by a peripheral subset of an established, alpine based species to a niche environment. However, the true explanation for their presence here in The Gurdies, is obscure at present. Indeed virtually everything about them - their origins, their numbers and distribution, their mode of living - is obscure at the present time.

Acknowledgments

The authors wish to thank Anne and Phil Westwood who provided much useful background information about Gippsland flora and fauna and J. Hillyard who provided information about an injured Bobuck. The authors also wish to thank Peter Menkhorst who reviewed the manuscript and suggested many useful improvements. The authors would like to thank, as well, an anonymous referee whose comments added significantly to the content of the paper that appeared in The Victorian Naturalist.

References

• Port Philip and Westernport Regional Catchment Strategy 2004-2009: Draft for Community Consultation August 2004. Port Philip and Westernport Catchment, Management Authority. ISBN 0 9750709
• 6, 7. Raithby JA and Beste H (1971), How to Photograph Australian Wildlife, Periwinkle Books, Lansdowne Press Pty Ltd, 346 St. Kilda Rd., Melbourne.
• Resources Information Sheet, November 1997, The Gurdies Nature Conservation Reserve, Department of Conservation & Natural Resources.

Updates 2005! How are The Gurdies Bobucks doing?

Uh Oh! Since early 2005 the Bass Highway, where it passes by the Bobucks' Creek has been widened. I heard the project was undertaken to accommodate the large volume of traffic that heads down to Phillip Island for the annual Motor Cycle Rally. As you can see, the reeds that were formerly 30 metres back from the road are now completely exposed to passing traffic. A careless cigarette butt tossed out a car window could start a fire and kill the Bobucks. What's needed is some kind of barricade to screen the creek. That won't protect them from deliberate arsonists but it'd be something. Reasonably cheap too.

The Gurdies in Flames!

The great Gurdies Controlled Burnoff gets under way. The project has been "in the works" for months. Dry leaf litter around the public picnic area has been building up to dangerous levels and the burn-off is designed to reduce the "fuel load". The problem is that certain morons who halt at the picnic ground think it's real good fun to set fire to the underbrush. By reducing the available fuel, the CFA hopes to diminish the odds of such fires taking off out of control.

The CFA crew take a short but welcome break. It's a difficult and sometimes dangerous job that they do. A column of smoke marks where the burn-off is taking place. But the CFA and Parks Victoria are doing a good job and the situation appears to be well under control. I sure hope they're doing a "cool reduction burn", one that's confined to the understorey. A fire that breaks loose into the forest canopy is immensely destructive.

Parks Victoria has copped a lot of undeserved bad press lately about their burn-off practices. But control burns are necessary. If you don't conduct limited, controlled burns when conditions are favourable, you are 100% certain to incur a disastrous, uncontrolled mega-fire later on. Then everything dies. It's a dilemma for sure but what are CFA, DSE and Parks Victoria supposed to do?

If you are a "Greenie", and I count myself as one, these are difficult questions you need to be able to answer because the Green Movement's opponents will seize upon them. My answer is that if the human race would inherit the Future, we need to live within the limits set by Nature. But we can manage our World for the good of all if we take care and if we wisely use our science and our technology. If we are of good will, the task is no load to bear. Trouble is, there are those with money and power and influence who are not of good will. They would put their own benefit above the future of Our World.

Extractive Mineral Industries and The Gurdies Bobucks

This relict population of Bobucks exists in a creek that flows alongside a major extractive industrial operation.The fact that they have survived here for, apparently, many decades is truly remarkable. QfT has tramped up and down the length of Bobuck Creek, yet we saw no trace of the quarry's pondage water, or silt from the excavations, contaminating the creek. The company's activities appear to be entirely confined within the quarry boundaries so that's a Good Thing.