A skiers guide to the small mammals of
the alpine and subalpine region.
By Garry Mayo. School of Botany and Zoology,
Australian National University.
Illustrations from original pencil drawings (not to
scale) by Melinda Perrin (with permission from NSW National
Parks and Wildlife Service)
Just occasionally while x-country skiing you might
see a small brownish animal on the snow. These animals are the small mammals
that live through out the year in our alpine and sub alpine zones. They
have adapted to life in the snow and many make use of the space between
the ground and the snow called the subnivian space. This space is relatively
warm and the temperature is mostly around zero, where there is a reasonable
snow cover. Bad snow years are not only a problem for skiers but it can
be disastrous for many of the small mammals. Deprived of this insulating
layer of snow the animals can succumb to the sub zero temperatures that
accompany winter. Ground temperatures approaching minus 30 degrees are
not uncommon in the frost hollows of the mountains.
Locally, the more common small mammal species are the,
Mountain Pygmy-possum, Broad-toothed Rat, Bush Rat, Dusky Antechinus and
Agile Antechinus. There are some other small mammals, you are very unlikely
to see, and these include Smoky Mouse and Eastern Pygmy-possum both of
which occur at lower elevations. It is possible that other species may
be resident with in the park, such as the Common Dunnart, but as yet have
not been found. I have not included the Water Rat, which is significantly
larger, but does occur in the park as do a number of bats species. All
of these animals are mostly nocturnal however some do forage in the daytime
and the most commonly sighted animals during winter are Bush Rats,
Broad-toothed Rats and the Dusky Antechinus. There are also non-native
animals such as the House Mouse and the Black Rat in the park.
Identification of the small mammals is generally difficult
for those without experience. However some animals do leave tell tail
signs and there are several excellent publications with good pictures
which will aid identification (see attached list). There are a few things
you can do to help identify the animals, but note you must not attempt
to capture them. This will stress the animal, you may also destroy its
home and it is also illegal. Some of the animals can also inflict painful
bites. Glimpses of mammals above the snow are mostly fleeting, if you
do see one then stay still and quiet. These animals have relatively poor
eyesight, which is more adapted to their nocturnal life, but they can
easily pick up movement. They do have excellent hearing and sense of smell.
If you get the opportunity
then try to get an idea of its size but note that immature animals
will obviously be smaller.
Estimate the relative
length of the tail to body.
Is the tail prehensile,
i.e. is it able to curl and grasp? This is a characteristic of both
species of possum.
Look at the fur (grey,
brown or greenish tinge) and tail colour and also note the belly colour
if you can see it.
Shape of the head, is
Has it left any droppings?
Note that the red to orange patches on the snow is the concentrated
urine produced by rabbits and hares.
Bush Rat Rattus fuscipes
Is a common species and can weigh up to 150 grams.
Tail is 90% of the body length. Fur is a grizzled grey to brown. Likes
scrubby areas with a lot of ground cover. Ranges more widely in winter
into the alpine herbfields when snow covers the ground. Mainly nocturnal.
Lives in extensive subnivian tunnel systems. Also lives in burrows in
the soil and their winter workings can be seen after the thaw as a trails
of soil mixed with the grass. Active throughout the year. These are often
mistaken as the introduced black rat in mountain huts.
Broad-toothed Rat Mastacomys fuscus
Listed as vulnerable.
Weighs up to 150g. Tail is around 72% of the body
length. Similar in colour to the bush rat but often has a green tinge
(particularly in summer) when there is algae growing on the fur as a result
of the damp conditions they live in. It can be distinguished from the
bush rat by its rounded and compact shape and relatively short tail. Found
in larger numbers in wet heaths along watercourses. Produces masses of
fecal pellets which are bright green drying to straw colour. Other animals
produce droppings that are mostly a dark black colour. They build grass
nests and extensive networks of tunnels under the snow that are revealed
in the thaw. Active through out the year.
Mountain Pygmy-possum Burramys parvus
Was only known from a fossil until the 1960s,
however, it was a frequent visitor to some of the chalets in the Victorian
Alps which lead to the capture of the first live specimen. Weighs up to
80 grams. Tail is 120% of the body length. Can
be distinguished from the Eastern Pygmy-possum by the thickened and fur
covered base of its tail. This thickened section is about a centimetre
long. The two species of pygmy-possums do not overlap in their distribution.
Pale grey in colour lighter underneath with some fawn colouration.
Mountain Pygmy-possums are generally restricted to
boulder fields and need this cool environment in the summer. They have
difficulty coping with temperatures over 28 degrees Celsius. Males and
females mostly live apart with the females occupying the most productive
habitat. The boulder fields are often associated with the mountain plum
pine and the while the possums rely extensively on insects for their food
that also eat a number of seeds including seeds from this plant. Interestingly
the possum has a specialised tooth that is adapted to cracking the hard
cases of beetles and seeds. In cracking open the seeds of the plum pine
it is the only small mammal that can crack the seeds laterally, rather
than along, the length of the seed. In winter they frequently go into
torpor (hibernation) for up to 6 days at a time when they can lower their
body temperature to just above the freezing point. This saves them a lot
of energy. The process of waking from torpor is extremely costly for them
energetically yet they need to do this to feed and excrete. They rely
on food caches and fat deposits, built up in summer, to see them through
the winter. Some do move around under the snow but it's thought
that their movements are limited. Their numbers are declining and although
not confirmed it is thought the warmer summers, longer periods with out
the snow cover and possibly the noise from machinery (waking the animals
from torpor) all affect their survival.
Eastern Pygmy-possum Cercartetus nanus
Up to 40 grams, fawn in colour and pale to white underneath.
Large dark eyes. Eastern Pygmy-possum tail is just shorter than the body
Has a thicker and more gradually tapering tail. Not usually found above
snow. Is restricted to forests and woodlands and feeds on nectar and pollen
as well as insects. Spends most of the winter in torpor. Like the Mountain
Pygmy-possum the animal curls into a ball while in torpor to conserve
Dusky Antechinus Antechinus swainsonii
Weighs up to 45 grams. The tail is around 80% of the body length. Brown
grey in colour and lighter underneath. It is darker and larger than Agile
Antechinus, has a pointed face and long curved claws. Typical of both
Antechinus species, who are insectivorous (eat insects) and have a very
pointed nose and jaw. Found anywhere there is sufficient ground cover
but prefers moister sites. As with other Antechinus the males all die
after the mating season. That means any animals you see in late September,
and for the next few months, will all be females. They mainly eat insects
and they live in burrows and hollow logs. Is active throughout winter.
Agile Antechinus Antechinus agilis
(formerly A. stuartii)
At around 25 grams is much smaller and paler than the
Dusky. The tail is around 80% of the body length. It is less common at
the higher altitudes around 2000m, prefers woodlands and rocky areas.
Its numbers increase with the tree cover. Similar diet to the Dusky but
exploits trees more extensively to hunt for beetles.
Smoky Mouse Pseudomys fumeus
Listed as endangered.
Only a few specimens of this animal have been recorded
within the park. Weigh up to 70 grams. Tail is 155% of the body length
and is distinctly bicoloured, pale to dark grey above and lighter underneath
and lightly furred. Feet pink with white fur. Their distribution is restricted
to heath where there is a diversity of legumes, epacrids seeds, insects
and fungi. Lives in burrows and is tolerant of the cold and active throughout
the winter. May not live above the usual snow line and not usually found
Mouse Mus musculus Up to 20 grams. House Mouse tail is a bit
shorter than the body. Colours are variable across Australia but generally
grey in the park. Identify can be confirmed by a notch behind the tip
of the upper incisors. They used to inhabit a number of huts above the
snow line although numbers are small and more likely occur in ski resorts.
Rat Rattus rattus Is known from some Victorian resorts and
has been recorded in the bush at Kosciuszko may now have established in
some resort areas of the park. Weighs up to 280 grams. Has not been able
to displace native rats but does get a foothold in areas disturbed by
man. You would be unlikely to see one of these at any time outside of
By applying the general rules of conservation you have
a good chance of having a minimal effect on any of the native species.
A few points for special consideration are:
- Trampling, particularly in areas where the snow
cover is thin, can break through damaging the tunnel networks and allowing
cold air to enter their subnivian world.
- Attempting to catch the animals is very stressful
and can cause their death.
- Skiing on and close to drainage lines increases
the risk that you will cross areas used by a number of the small mammals
and possibility damaging their habitat.
- You should not leave food or food scraps anywhere
and keeping huts clean reduces the possibility of introduced species
getting a hold in the area.
- The removal of firewood has a direct impact on home
sites and food availability.
- If "rats" become a problem in ski lodges
it is probable that they are native rats or possums. Contact the NPWS
and they will trap the animals and release them safely back into their
habitat. It is preferable to try to "rat-proof" buildings
and storerooms if possible, as the trauma of trapping and releasing
a native rat or possum in a strange location may be fatal to the animal.
During winter 2002 and 2003 Glenn Sanecki from the Centre
for Resource and Environmental Studies at the Australian National University
will research the activity and location of small animals. To do this he
is fitting radio transmitters to some animals. Monitoring pipes (90mm
stormwater pipe) have been installed in groups of three in various
habitats in the Perisher Range area and are designed to identify animals
from hair samples collected.
There is a lot of good reading about mammals which
- Wildlife of the Australian Snow Country by Green
and Osborne ISBN 0 7301 0461 3.
- The Mountain Pygmy Possum of the Australian Alps
by Mansergh and Broome ISBN 0 86840 085 8.
- The Mammals of Australia Ed by Strahan ISBN 1 87633
- Tracks, Scats and other Traces. A field guide to
the Australian Mammals by Barbara Triggs ISBN 0 19 553643 6.
- The Rodents of Australia. Watts and Aslin ISBN
0 207 14235 1.
Rare sighting of a bird at Perisher.
The Nankeen Night Heron pictured, was observed
in a tree at Perisher Valley on the 20th January 2002 and according to
Dave Woods, ranger with the NPWS, it is a rare sighting at this altitude
and in this area. The bird stayed in the same tree for three days and
was timid and if approached too closely it would fly away. It is not known
if it built the nest observed in the tree. The bird was not to be seen
when NPWS checked a month later.
The Nankeen Night Heron will be nominated
as the mascot for the Smiggin Holes Olympics in 2010.
The NPWS is always interested to receive
reports of any sighting of birds, animals and plants and can help with
For more information go to footprints,