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DISPLAYING POSTS BY: Phoebe Burns (4)

Eastern Pygmy Possum

Author
by Phoebe Burns
Publish date
15 August 2014
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Comments (1)

Phoebe is a University of Melbourne Masters student supervised by Dr. Kevin Rowe at MV. She is passionate about the unique mammal fauna of Australia.

Early one morning, while up in the Grampians searching for Smoky Mice (Pseudomys fumeus), I peeked inside an Elliot trap and was greeted by a delicate little face, huge ears, big bright eyes and fat, gently curled tail. Expecting to see the pointy face and straight, slender tail of an Agile Antechinus (Antechinus agilis), I hastily shut the trap, took a second to process the surprise and then beamed at my bemused volunteer. Another tentative peek in the trap confirmed it; I had trapped my first Eastern Pygmy Possum (EPP; Cercartetus nanus).

Eastern Pygmy Possum Eastern Pygmy Possum
Image: David Paul
Source: Museum Victoria
 

The EPP weighs in at a miniscule 15-38g1, yet still looks truly possum-like. It is one of seven possum species you could fit in your pocket, but is far from the smallest. The Little Pygmy Possum (Cercartetus lepidus) weighs only 6-10g and a full-grown Honey Possum (Tarsipes rostratus) can weigh as little as 5g1.

Like several other possum species, EPPs can obtain all required nutrients, including protein, from nectar and pollen alone.2 However they also eat insects, seeds and fruit, providing flexibility when few plants are flowering. Like the Fat-tailed Dunnart, the EPP stores fat at the base of its tail as a reserve for when food is scarce, and can go into torpor when keeping active is energetically too expensive.

Eastern Pygmy Possum Eastern Pygmy Possum
Image: David Paul
Source: Museum Victoria
 

As another of Australia’s amazing marsupial species, the female EPP gives birth to tiny eyeless, earless babies that suckle in her pouch for 30 days. Once the juveniles are too big for the pouch, they nest with their mother for another 30-35 days then head off alone.3 EPPs don’t build their own nests; they use whatever is available and change nest sites frequently. Researchers have found EPPs nesting in tree hollows, abandoned birds nests, burrows and natural collections of leaves and twigs in tree forks.3

Phoebe Burns with an adult female eastern pygmy possum Phoebe Burns with an adult female eastern pygmy possum (Cercartetus nanus) in the Grampians National Park.
Image: Kara Joshi
Source: Museum Victoria
 

 

Eastern Pygmy Possums are patchily distributed from the southeast corner of Queensland to the southeast tip of South Australia, Flinders and King Islands and throughout Tasmania. They are listed as near threatened in Victoria; at risk from predation by foxes and cats, competition with feral honeybees and increasing fire frequency.4 I consider myself so lucky to have encountered such a charming species and hope there are many more (pleasant) surprises in my traps for years to come.

References

1.         Menkhorst, P. & Knight, F. Field Guide to the Mammals of Australia. (Oxford University Press, 2011).

2.         Van Tets, I. G. & Hulbert, A. J. A Comparison of the Nitrogen Requirements of the Eastern Pygmy Possum, Cercartetus nanus, on a Pollen and on a Mealworm Diet. Physiological and Biochemical Zoology 72, 127–137 (1999).

3.         Ward, S. Life-History of the Eastern Pygmy-Possum, Cercartetus nanus (Burramyidae, Marsupialia), in South-Eastern Australia. Australian Journal of Zoology 38, 287 (1990).

4.         Harris, J. M. & Goldingay, R. L. Distribution, habitat and conservation status of the eastern pygmy-possum Cercartetus nanus in Victoria. Australian Mammalogy 27, 185–210 (2005).

Fat-tailed Dunnart

Author
by Phoebe Burns
Publish date
4 August 2014
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Comments (0)

Phoebe is a University of Melbourne Masters student supervised by Dr. Kevin Rowe at MV. She is passionate about the unique mammal fauna of Australia.

There are 360 mammal species native to Australia. I'd challenge you to name them all, but even as a mammalogist (albeit early in my career) I'm still coming across species I haven't heard of. Even so, there are relatively common species I'm always surprised people don't know, for instance: what is a dunnart?

The Fat-tailed Dunnart (Sminthopsis crassicaudata) is one of 19 dunnart species. It is a small (10-20g) insect-eating dasyurid, which means that although it's mouse-sized, the dunnart is in the same family as the Tassie devil.

Fat-tailed Dunnart Fat-tailed Dunnart (Sminthopsis crassicaudata).
Image: David Paul
Source: Museum Victoria
 

The females give birth a mere 13 days after conception to 8-10 tiny immature young that are about one-eightieth the size of a new-born house mouse. The young suckle for around 65 days, moving from the pouch to their mother's back once they grow too large to fit.

Fat-tailed Dunnart Fat-tailed Dunnart scratching an itchy spot.
Image: David Paul
Source: Museum Victoria
 

Aptly named for their thick tails, the Fat-tailed Dunnart stores about 15 per cent of its body fat in the tail. This provides the animal with a back-up energy reserve during times when food is scarce. Torpor is another method the dunnart uses for dealing with an uncertain environment – when food availability becomes unpredictable they curl up, let their body temperature drop, and their metabolic rate slows. Torpor allows a dunnart to conserve energy when there is so little food around that they would burn more energy finding it than they could obtain eating it.

Fat-tailed Dunnart The thick tail of the Fat-tailed Dunnart contains fat stores that helps it survive in harsh conditions.
Image: David Paul
Source: Museum Victoria
 

Fat-tailed Dunnarts occupy a wide range of habitats across most of south and central Australia. They are one of a few native mammal species that can be kept as a pet in Victoria with a basic wildlife license, provided the animal is legally obtained and not taken from the wild.

If you want to learn more about our native fauna check out the Museum Victoria Field Guide app, and our sister apps for the rest of Australia.

Smoky mouse update

Author
by Phoebe Burns
Publish date
25 February 2014
Comments
Comments (3)

Phoebe is a University of Melbourne Masters student supervised by Dr. Kevin Rowe at MV. She is studying post-fire distribution and ecology of the Smoky Mouse in the Grampians National Park.

In September 2013, I moved to the Grampians, pitched a tent and set out to see how the endangered Smoky Mouse, Pseudomys fumeus, was faring in the aftermath of the February 2013 Victoria Valley fire. After three soot-covered months, I’m back in Melbourne enjoying modern comforts like showers and instant boiling water.

Grampians landscape Grampians landscape
Image: Phoebe Burns
Source: Museum Victoria
 

I began my surveys at the site where, prior to the fire, we found a healthy population of Smoky Mice in the November 2012 Museum Victoria Bioscan. By September regrowing bracken ferns and eucalypts added a splash of green to the blackened landscape. In spite of the devastation, I caught several healthy Smoky Mice including some of the same individuals we’d caught the previous November! The ecological significance of this discovery alone was cause to celebrate.

Adult Smoky Mouse Adult Smoky Mouse on a burnt log
Image: Phoebe Burns
Source: Museum Victoria
 

Between my first capture in September and my final trapping night in December, I surveyed 46 sites in and out of the burn scar across the Victoria Range in the Grampians. At six of those sites, all within the burn scar, I found Smoky Mice living in the rocky habitats. The mice in these populations were not just surviving, they were healthy and breeding. I caught adults weighing as much as 70 grams but I also found tiny juveniles newly emerged from the nest weighing only 12 grams.  

Juvenile Smoky Mouse Juvenile Smoky Mouse
Image: Phoebe Burns
Source: Museum Victoria
 

While I was looking to find Smoky Mice, my trapping methods meant I also caught a number of other small mammal species (and a few reptiles). I was lucky enough to encounter Swamp Rats, Rattus lutreolus, Heath Mice, Pseudomys shortridgei, Agile Antechinus, Antechinus agilis, and Dusky Antechinus, Antechinus swainsonii. The highlights of my small mammal by-catch were two tiny Eastern Pygmy Possums, Cercatus nanus, that found their way into my traps.

Eastern Pygmy Possum Adult female Eastern Pygmy Possum
Image: Phoebe Burns
Source: Museum Victoria
 

The last three months were physically and mentally challenging, hiking up mountainsides in the rain and hail, being snowed on one day and sweating in the heat the next, but it was worth every unpredictable minute. I feel so privileged to explore the beautiful, rugged wilderness of the Grampians National Park and to have encountered so many remarkable species. The Parks Victoria staff provided a wealth of logistical and emotional support. It’s great to know that our parks are in such capable hands and that the Smoky Mice of the Victoria Range are thriving in spite of the fires.

Links:

MV Blog: Smoky Mice in the Grampians

Smoky mice in the Grampians

Author
by Phoebe Burns
Publish date
31 May 2013
Comments
Comments (3)

Phoebe is a University of Melbourne Masters student supervised by Dr. Kevin Rowe at MV. She is studying post-fire distribution and ecology of the Smoky Mouse in the Grampians National Park

Smoky Mouse Smoky Mouse, Pseudomys fumeus. Grampians, November 2012.
Image: David Paul
Source: Museum Victoria
 

The Smoky Mouse (Pseudomys fumeus) is an elusive and endangered rodent native to southeast Australia. Historically, the Grampians in western Victoria have been home to healthy populations of the mouse, though years can pass without observations of the species. During the November 2012 Museum Victoria Bioscan, we found a large population of Smoky Mice in the Victoria Range in the west of the Grampians; an amazing find as the mouse had not been detected in such high numbers since the 1980s!

In February 2013 a wildfire burnt through 35,000 hectares of the Grampians, including 80 per cent of the Victoria Range and the locations we surveyed in November. While such a large fire raised concerns about the survival of the Smoky Mouse population, we’re using the opportunity to understand how the species responds to fire. So far things are looking promising: earlier this month we found evidence of rodent activity in a small sheltered patch in the middle of a burnt gully and the vegetation is regenerating well. Excitingly, Parks Victoria staff have detected Smoky Mice on cameras in the southern end of the Victoria Range.

Fire has shaped the communities of plants and animals that live in the Grampians, but we still have so much to learn about the role it plays in the lives of our native rodents. Regular burns are essential to the reproduction of some plant species, which in turn provide habitat for our animal species. The Smoky Mouse relies on specific plant communities to provide food and shelter; fire is necessary to ‘reset’ these plant communities to prevent them growing to a point where they are no longer suitable for the mouse. However, fire is best delivered in a patchy mosaic, allowing animals to live in unburnt areas while adjacent burnt areas regenerate and the plant community returns to a suitable state. Wide-scale fires like the one in February are not ideal, and we’re eager to learn what impact it may have on the native fauna.

We’re hopeful that the Smoky Mouse is living in unburnt patches throughout and around the burnt areas. Over time the Smoky Mouse will recolonise the recently burnt areas and we’ll be able to map the movement of the species across the landscape using genetic techniques. In the short term, I will be hiking around the Grampians monitoring the progress of the Smoky Mouse over the next year. I hope to learn where the mouse is persisting and how the species responds to fire in order to help plan management techniques to ensure the conservation of the species for generations to come.

  Smoky Mouse Smoky Mouse, Pseudomys fumeus. Grampians, November 2012.
Image: David Paul
Source: Museum Victoria

Links:

YouTube video: Moth hunting at the Grampians

MV Blog: Gallery of the Grampians survey

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