MV Blog

DISPLAYING POSTS TAGGED: mammals (14)

The New Holland mouse

Author
by Phoebe Burns
Publish date
31 July 2015
Comments
Comments (1)

The New Holland mouse (Pseudomys novaehollandiae) is one of Victoria’s threatened native rodents. The charismatic little species has only been recorded in three areas across the state in the past 15 years (the blue dots in the map below), whereas historically it was recorded in ten, including metropolitan Melbourne (the red dots in the map below). That’s why I embarked upon a PhD to determine the status of NHMs across Victoria and help protect this species from further decline.

New Holland mouse detection sites New Holland mouse detection sites across Victoria. Red dots indicate sites in areas where the species has not been detected in at least 15 years, blue dots indicate areas with more recent detections. Dates show the range of years during which New Holland mice were known at each site.

One of the greatest challenges for studying the status and conservation of New Holland mice (and many native Australian rodents) is that they can be very difficult to find; you can’t just see them with your binoculars or hear them calling in the bush. Many native rodents, including NHMs, go through natural periods where they persist in such low numbers that traditional survey efforts fail to detect them. New Holland mice are also particularly fickle about their habitat preferences and may only persist locally for a few years before moving on, making their populations even more difficult to track.

New Holland mouse captured and released New Holland mouse captured and released using live trapping.
Image: Phoebe Burns
 

That’s why I’ve been trialling the use of cameras to detect the New Holland mouse. Traditional live trapping can be a great method for detecting a species in an area, and it’s critical if I want to know about health and reproduction, estimate abundance, or get DNA samples. However, sometimes when a species is at low densities, it takes a huge amount of effort to be reasonably confident that the species isn’t there, which in a world of limited time and funding drastically reduces the area you can survey. This is a real challenge when your species moves in the landscape.

This is where cameras can come in handy – you set them once and, rather than having to come back every morning and afternoon to check each trap, you can just leave them in place for weeks at a time. The animals are attracted to a tasty lure (I like to use peanut butter, oats, golden syrup and vanilla essence), and while they investigate, the camera senses the heat and motion and snaps a photo.

New Holland mouse Camera trap image of a New Holland mouse clinging to a bait station.
Image: Phoebe Burns
 

Cameras allow you to survey much wider areas, for longer periods of time with a fraction of the effort of live trapping – at least until you have to sift through all the images and identify the animals. Once I know that NHMs are present in an area from the camera trapping, I can target those areas for live trapping to collect the rest of my data. My challenge, and the reason I did a camera trial, rather than just jumping straight into using cameras as a survey method, was identifying New Holland mice in the images.

New Holland mouse and house mouse Camera trap image of a New Holland mouse climbing on a bait station with a house mouse standing up against the base.
Image: Phoebe Burns
 

Rodents tend to look very similar on camera, particularly if the images are in black and white. It doesn’t help that New Holland mice are about the same size as the non-native house mice (Mus musculus); they can be hard for some people to tell apart when they are holding them in their hand. Since the house mouse has infiltrated all known New Holland mouse habitat in Victoria, I needed to tell them apart from less than perfect images in colour and in black and white.

New Holland mice and house mice Infrared camera trap images of New Holland mice (left) and house mice (right) investigating bait stations.
Image: Phoebe Burns
 

Tens of thousands of images later, I can happily say that New Holland mice and house mice are distinguishable from one another in both colour and black and white images. In the colour images the species can be distinguished by differences in colouration, but in black and white the distinction is all in the shape of the two rodents. New Holland mice have a much sturdier build, a thickset neck and a snubby nose, whereas house mice are much more slender, with a pointed nose. It's not unlike the difference between rugby and footy players.

Now that I’ve got the IDs sorted, I’ll be using cameras (and live traps) to survey across Victoria and see where the New Holland mouse is persisting, so that we can do our best to halt the species’ further decline.

You can follow my PhD progress and fieldwork on Twitter and at my website to stay up to date with the status of New Holland mice as I search for them throughout Victoria.

Additionally, you can try your hand at identifying New Holland mice in my New Holland mouse quiz.

Eastern Pygmy Possum

Author
by Phoebe Burns
Publish date
15 August 2014
Comments
Comments (2)

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
Comments
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.

Exploration of Sulawesi, Indonesia

Author
by Bonnie & Rashika
Publish date
11 November 2013
Comments
Comments (0)

Bonnie Gambhir is a Computer Science student with interests in scientific exploration. Rashika Premchandralal is pursuing a Master’s Degree in Biotechnology. Both are studying at the University of Melbourne.

This is the second post of an MV Blog mini-series celebrating the past, present and future of exploration on planet Earth and commemorating the adventures of Alfred Russel Wallace who died 100 years ago.

Wallace's exploration of the islands of Indonesia contributed to the theory of evolution by natural selection, as well as the field biogeography–the study of the distribution of species over space and time. Wallace famously divided the world’s animals into zoogeographic regions, with his travels through modern day Indonesia providing important clues about the transitions of more Asian-like species to those of Australian origin.

"The island of Sulawesi is a place where many Asian lineages get their easternmost distribution and many Australian lineages get their westernmost distribution, and Sulawesi represents a mixture of the flora and fauna of these two great continents," says Dr Kevin Rowe.

Skull of Babirusa MV specimen R8050: skull of Babirusa, Babyrousa celebensis, an ancient lineage of pigs on Sulawesi. Pigs are not native to the Australian continent and Sulawesi represents their easternmost distribution.
Image: Karen Rowe
Source: Museum Victoria
 

mount of Bear Cuscus MV specimen C27221: mount of Bear Cuscus, Ailurops ursinus. An ancient relative of the Ringtail Possum, the Bear Cuscus is endemic to Sulawesi and represents the westernmost distribution of Australian marsupials that never reached the Asian continent.
Image: Karen Rowe
Source: Museum Victoria
  

Since Wallace’s time, further scientific exploration in Wallacea has contributed immensely to our understanding of the distribution and evolution of species.

Researchers at Museum Victoria are continuing this exploration on the island of Sulawesi; Dr Kevin Rowe and Dr Karen Rowe have made several expeditions in recent years, leading to the description of new mammal species and new knowledge of the evolutionary relationships between Indonesian and Australian birds.

When Wallace visited Sulawesi, he recorded only five species of rodents. Today, we recognise almost fifty. Described in 2012 by Kevin and colleagues, one recently- discovered species from Sulawesi challenges the definition of rodent. The unique rat, Paucidentomys vermidax, (meaning “few-toothed worm-devouring mouse”) is the only rodent, among more than 2,200 species, with pointed upper incisors and no molars.

Dr Kevin Rowe with Paucidentomys vermidax Dr Kevin Rowe with Paucidentomys vermidax, a nearly toothless rodent, on the day of its discovery in the rainforests of Sulawesi.
Image: Kevin Rowe
Source: Museum Victoria
 

The honeyeater family Meliphagidae is one of the most diverse groups of Australian birds. Most of the nearly 170 species are found in Australia, New Guinea and adjacent Pacific Islands. A few species are native to Wallacea where the family reaches the westernmost limits of its distribution. Through her fieldwork on Sulawesi, Karen is studying the endemic genus Myza and their relationship to all other honeyeaters.

Lesser Sulawesi Honeyeater Lesser Sulawesi Honeyeater, Myza celebensis, found in the forests of Mount Dako, Sulawesi in 2013.
Image: Karen Rowe
Source: Mustum Victoria
 

Expeditions to Sulawesi by MV researchers and their Indonesian and US colleagues have produced several new records of species that have not been recorded since the 1970s. Many of these species were previously known from a single locality and are listed as 'data deficient' by the IUCN Red List of Threatened Species. Hence the recent exploration of Sulawesi is helping to improve understanding of the habitat requirements and distributions of these little-known species.

Local knowledge and assistance is as much a part of modern exploration as it was in Wallace’s time. Our final post in this series will explore how international cooperation has contributed to the success of Museum Victoria’s research in the region.

Links:

MV Blog posts about Sulawesi field research

Return from Mount Dako

Author
by Kevin Rowe
Publish date
2 April 2013
Comments
Comments (0)

Kevin is our Senior Curator of Mammals. He investigates the systematics, evolution and conservation biology of mammals with a particular interest in rodents.

On Saturday 23 March, we returned to Melbourne from our expedition to Sulawesi, Indonesia. Our last week we spent at the Museum Zoologicum Bogoriense sorting specimens and preparing permits to return to Australia. A week earlier on 16 March, we left our camp in the forest of Mount Dako on the island of Sulawesi. We hiked all day from 1600 metres above sea level to the village of Malangga Selatan at 200 metres. Our team at 400 metres elevation also left camp and met us in the town of Toli Toli.

Sulawesi field team The mammal team and guides at 1600m elevation on the last day in the high camp on Mount Dako. Left to right: Kevin Rowe, Mardin Sarkam, Anang Achmadi, Jamudin, Jake Esselstyn, and Jamal.
Image: Karen Rowe
Source: Museum Victoria
 

It wasn’t easy to get to our camps on Mount Dako. After a week of permits in Jakarta, a week of scouting two mountains, and several days arranging local assistance, we finally arrived in Malangga Selatan ready to hike up the mountain. With over 300 kg of gear, our team of ten researchers, and fifty local men waiting to help us up the mountain, our local guide, Jamudin, suddenly expressed concern about water on the mountain. Apparently we were going farther into the forest than he was accustomed. We showed him the many drainages on the map that all fed into a big river to the east, but our only option to convince him was to send another scouting party two days hike up the mountain. The rest of our team and the porters set the low elevation camp. After two days, I reached the crest south of Mount Dako with our scouting party and made camp beside a small stream. That night the rain fell heavy for several hours and our tent flooded in the rain. We sought shelter with our guides under a tarp and spent several hours sitting on a small log until the rain subsided enough to return to our tent. The next day we sent two of our guides down the mountain to return with the rest of our team and our gear two days later. We moved our camp to a drier location farther up the ridge and enjoyed the only two days without rain for the rest of our trip.

Sulawesi moss forest Lush and wet lower montane moss forest near camp at 1600 metres elevation on Mount Dako.
Image: Kevin Rowe
Source: Museum Victoria
 

Our high camp was set in lower montane rainforest with moss-covered trees including oaks and pandanus. Even when it’s not raining, clouds bring moisture to the forest and there is nearly constant dripping. Orchids and pitcher plants grow in the moisture of the moss. Spiny rotan erupt from tiny plants on the forest floor to tree size vines emerging from the canopy. They climb with the aid of curved thorns that grip human hands and bodies as easily as the trunks of trees.

Plants of Sulawesi Left: Spiny palm tree along the trail to the high camp on Mount Dako. Right: Pitcher plant in lower montane forest.
Image: Kevin Rowe
Source: Museum Victoria
 

Over the last two weeks, our two camps documented 26 species of bats, rats and shrews and 31 species of birds in the forests of Mount Dako. In total, our surveys produced nearly 500 mammal and 150 bird records.

We documented a wide range of mammal species including the giant rat, Paruromys dominator, the small orange-brown rat, Maxomys musschenbroekii, the long-haired rat, Rattus xanthurus, the soft-furred rat, Bunomys penitus, and the small arboreal mouse, Haeromys minahassae. We documented two squirrels, the small arboreal, Prosciurillus murinus, and the long-nosed, terrestrial, Hyosciurus ileile. We also documented five species of shrews, including the dark-furred, Crocidura rhoditis.

Three Sulawesi mammals Three of the mammals recorded in Mt Dako's lower montane forests. Top: Giant rat, Paruromys dominator. Middle: The soft-furred rat, Bunomys penitus. Bottom: The long-nosed squirrel, Hyosciurus ileile.
Image: Kevin Rowe
Source: Museum Victoria
 

Many endemic and beautiful bird species were documented as well, including the Green-backed Kingfisher, Lesser Sulawesi Honeyeater, Sulawesi and Hair-crested Drongos, Malia, Philippine Scrubfowl, Yellow-flanked Whistler, Fiery-browed Starling, Golden-mantled Racquet-tail, and two species of small hawks, the Spot-tailed Goshawk and Vinous-breasted Sparrowhawk.  Many species of fruit-doves were also noted, including the Sulawesi Ground-dove, Purple-crowned Fruit-dove and Black-naped Fruit-dove. Population densities of several species were high, including the Yellow-sided Flowerpecker. This species is in the same family as Australia’s Mistletoebird, which is often only found singly or in pairs. An exciting find was the large Ashy Woodpecker. Sulawesi represents a limit to the distribution of woodpeckers, which are found world-wide with the exception of the Australo-Pacific region.

Two birds of Sulawesi Left: The Green-backed Kingfisher found in lower montane forest on Mount Dako. Right: The endemic Malia found at 1600 m on Mount Dako.
Image: Karen Rowe
Source: Museum Victoria
 

Our return to Melbourne is only the beginning of our studies as now we begin the cleaning and detailed examination of specimens, including genetic sequencing and comparison to described specimens to confirm identifications and examine geographic variation within species. Our collections from Mount Dako are a rare collection from the western portion of the northern peninsula of Sulawesi. They will help us understand the diversity, distribution, and origin of species on the island of Sulawesi and its significance in the biogeography of the Indo-Australian region. That understanding will emerge through our research at Museum Victoria and our collaboration with the Museum Zoologicum Bogoriense and our international partners in Canada and the USA. 

Discoveries in the jungle

Author
by Priscilla
Publish date
13 March 2013
Comments
Comments (0)

Priscilla is a Program Coordinator for Life Sciences and works on education programs at Melbourne Museum.

"There’s still plenty to discover in the jungles of Sulawesi," said Dr Kevin Rowe yesterday, via satellite phone from the jungles of Indonesia. He was phoning in to HQ – Museum Victoria, that is; he and his field crew are deep in the jungle, with email access a day’s hike away.

Dr Kevin reported that he and MV Ornithology Fellow, Dr Karen Rowe, have been enjoying great success on their current field trip. “To date, we’ve caught eight species of rats, two species of squirrels, five species of shrews and 13 species of birds”. He further explained that these mammals are all endemic, meaning that they are not to be found anywhere else in the world.

The crew has two camps set up at different altitudes. Kevin and Karen are camped at an altitude of 1600 metres, while Wayne Longmore, Museum Victoria’s Collection Manager of Terrestrial Vertebrates, is working with others at 400 metres above sea level.

While we here in Melbourne have been melting, during the hottest March since records began, Kevin and the crew have been experiencing endless rain. "Rain, rain and more rain, with days reaching a maximum of 16 degrees Celsius" said Kevin. "It’s a big cloud forest here, which leads to a lot of moss on the trees." And where there’s endless rain, there’s plenty of mud, making the work of our scientists tougher as they set out their 240 traps each night, ahead of collecting and checking them all the very next day and processing the data in daylight.

Birdsong metre demonstration The birdsong metre being demonstrated by museum volunteer, Bentleigh, during a trip to the Grampians.
Source: Museum Victoria

Dr Karen Rowe said that they had found many birds on this trip too, including honeyeaters, fantails and goshawks. Simply trying to sight these birds can be very difficult in thick jungle, however, so, to better understand the bird life of Sulawesi, she has been using a song meter to automatically record birdsong, which she can analyse later to determine which birds are living in the area.

The crew are in the jungle until this Saturday, when they will hike out at night. Through the rain, Kevin says "the views of the jungle from the lookouts are beautiful." However, they have only a few more days to enjoy the sights; they'll be back in Melbourne a week from Saturday. Meanwhile, there just may be some more discoveries yet to be made...


View Sulawesi Field Team in a larger map

About this blog

Updates on what's happening at Melbourne Museum, the Immigration Museum, Scienceworks, the Royal Exhibition Building, and beyond.

Categories