Southwestern Pygmy Possum
Encyclopedia
The southwestern pygmy possum (Cercartetus concinnus), commonly known as the western pygmy possum or the mundarda, is a small marsupial
found in Australia. Genetic studies indicate that the closest relative of this species is probably the eastern pygmy possum
, from which its ancestors diverged around eight million years ago.
, as, unlike its grey relatives, the fur over most of its body is a bright cinnamon colour. It has pure white underparts, which also distinguishes it from its relatives, and has a relatively indistinct patch of darker fur in front of the eyes. It possesses larger, oval ears, large eyes, and long whiskers
. The tail is long and prehensile, and is covered with fine scales, rather than fur. The hind feet have an opposable first digit
, while all four feet have broad pads at the tips of the toes.
Although small compared with most other possum
s, it is one of the larger pygmy possums, with adults ranging from 5.7 – in head-body length with a 7.7 –, tail. Adult weight ranges from 8 –. The female has a well-developed pouch, opening to the front, and containing six teats. At up to 1.2 centimetre (0.47244094488189 in) in length, the tongue is unusually large for such a small animal.
and Victoria south to Edenhope. It is also found on in far south-western New South Wales
, where it is listed as endangered. It inhabits semiarid woodland, shrubland and heath, dominated by plants such as bottlebrushes, melaleuca
, banksia
, and grevillea
. Although there had been previously thought to be two subspecies, separated in distribution by the Nullarbor plain
, genetic studies have not revealed any significant difference between the eastern and western populations. Furthermore, while the species is no longer native to the area, fossils from the Nullarbor plain region are known.
It feeds primarily on nectar and pollen
, especially from plants such as melaleuca and eucalyptus
, and may play a role in the pollination
. It also supplements its diet with small amounts of insects. Native predators include quoll
s, snakes, and owls, although in modern times the animal also falls prey to introduced carnivores such as red fox
es and domestic cats.
Southwestern pygmy possums have the ability to enter torpor
during inclement or cold weather, enabling them to conserve energy and food reserves. During bouts of torpor, which may last for up to seven days at a time, body temperature falls to within one degree Celsius of ambient, and oxygen consumption to just 1% of normal. They sleep on their front, with their ears folded over their eyes, and the long tail coiled beneath their body. Compared with other mammals of similar size, they rouse from torpor unusually quickly.
.
The young are still blind when they leave the pouch at around 25 days of age; they initially remain within the nest, and are fully weaned at around 50 days. Females reach sexual maturity at twelve to fifteen months.
Marsupial
Marsupials are an infraclass of mammals, characterized by giving birth to relatively undeveloped young. Close to 70% of the 334 extant species occur in Australia, New Guinea, and nearby islands, with the remaining 100 found in the Americas, primarily in South America, but with thirteen in Central...
found in Australia. Genetic studies indicate that the closest relative of this species is probably the eastern pygmy possum
Eastern Pygmy Possum
The Eastern Pygmy Possum is a diprotodont marsupial of south-eastern Australia. Occurring from southern Queensland to eastern South Australia and also Tasmania, it is found in a range of habitats, including rainforest, sclerophyll forest, woodland and heath.This species is very small, weighing...
, from which its ancestors diverged around eight million years ago.
Description
The southwestern pygmy possum is unusual among the members of its four-strong genusCercartetus
The genus Cercartetus is a group of very small possums known as pygmy possums. Four species comprise this genus, which together with the genus Burramys make up the marsupial family Burramyidae....
, as, unlike its grey relatives, the fur over most of its body is a bright cinnamon colour. It has pure white underparts, which also distinguishes it from its relatives, and has a relatively indistinct patch of darker fur in front of the eyes. It possesses larger, oval ears, large eyes, and long whiskers
Vibrissae
Vibrissae , or whiskers, are specialized hairs usually employed for tactile sensation. The term may also refer to the thick hairs found inside human nostrils, but these have no sensorial function and only operate as an airborne particulate barrier...
. The tail is long and prehensile, and is covered with fine scales, rather than fur. The hind feet have an opposable first digit
Hallux
In tetrapods, the hallux is the innermost toe of the foot. Despite its name it may not be the longest toe on the foot of some individuals...
, while all four feet have broad pads at the tips of the toes.
Although small compared with most other possum
Possum
A possum is any of about 70 small to medium-sized arboreal marsupial species native to Australia, New Guinea, and Sulawesi .Possums are quadrupedal diprotodont marsupials with long tails...
s, it is one of the larger pygmy possums, with adults ranging from 5.7 – in head-body length with a 7.7 –, tail. Adult weight ranges from 8 –. The female has a well-developed pouch, opening to the front, and containing six teats. At up to 1.2 centimetre (0.47244094488189 in) in length, the tongue is unusually large for such a small animal.
Distribution and habitat
It has a patchy distribution which includes southwestern Western Australia as well as wheatbelt areas of South Australia, Kangaroo IslandKangaroo Island
Kangaroo Island is Australia's third-largest island after Tasmania and Melville Island. It is southwest of Adelaide at the entrance of Gulf St Vincent. Its closest point to the mainland is off Cape Jervis, on the tip of the Fleurieu Peninsula in the state of South Australia. The island is long...
and Victoria south to Edenhope. It is also found on in far south-western New South Wales
New South Wales
New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...
, where it is listed as endangered. It inhabits semiarid woodland, shrubland and heath, dominated by plants such as bottlebrushes, melaleuca
Melaleuca
Melaleuca is a genus of plants in the myrtle family Myrtaceae known for its natural soothing and cleansing properties. There are well over 200 recognised species, most of which are endemic to Australia...
, banksia
Banksia
Banksia is a genus of around 170 species in the plant family Proteaceae. These Australian wildflowers and popular garden plants are easily recognised by their characteristic flower spikes and fruiting "cones" and heads. When it comes to size, banksias range from prostrate woody shrubs to trees up...
, and grevillea
Grevillea
Grevillea is a diverse genus of about 360 species of evergreen flowering plants in the protea family Proteaceae, native to Australia, New Guinea, New Caledonia, and Sulawesi. It was named in honour of Charles Francis Greville. The species range from prostrate shrubs less than 0.5 m tall to trees...
. Although there had been previously thought to be two subspecies, separated in distribution by the Nullarbor plain
Nullarbor Plain
The Nullarbor Plain is part of the area of flat, almost treeless, arid or semi-arid country of southern Australia, located on the Great Australian Bight coast with the Great Victoria Desert to its north. It is the world's largest single piece of limestone, and occupies an area of about...
, genetic studies have not revealed any significant difference between the eastern and western populations. Furthermore, while the species is no longer native to the area, fossils from the Nullarbor plain region are known.
Behaviour and diet
The southwestern pygmy possum is solitary and nocturnal. During the day they shelter in tree hollows or other natural crevices, birds' nests, or dense vegetation. During the night, they travel in search of food or mates, typically moving around 50 metres (164 ft) each day, and they may migrate to different areas over the course of a year, depending on local plant resources. They spend most of their time in the trees, using their grasping paws and prehensile tails to grip onto branches, grasp nest materials, and open flowers to access nectar. They have been described as making a rapid chattering noise.It feeds primarily on nectar and pollen
Pollen
Pollen is a fine to coarse powder containing the microgametophytes of seed plants, which produce the male gametes . Pollen grains have a hard coat that protects the sperm cells during the process of their movement from the stamens to the pistil of flowering plants or from the male cone to the...
, especially from plants such as melaleuca and eucalyptus
Eucalyptus
Eucalyptus is a diverse genus of flowering trees in the myrtle family, Myrtaceae. Members of the genus dominate the tree flora of Australia...
, and may play a role in the pollination
Pollination
Pollination is the process by which pollen is transferred in plants, thereby enabling fertilisation and sexual reproduction. Pollen grains transport the male gametes to where the female gamete are contained within the carpel; in gymnosperms the pollen is directly applied to the ovule itself...
. It also supplements its diet with small amounts of insects. Native predators include quoll
Quoll
The quoll, or native cat, is a carnivorous marsupial native to mainland Australia, New Guinea and Tasmania. It is primarily nocturnal and spends most of the day in its den. There are six species of quoll; four are found in Australia and two in New Guinea...
s, snakes, and owls, although in modern times the animal also falls prey to introduced carnivores such as red fox
Red Fox
The red fox is the largest of the true foxes, as well as being the most geographically spread member of the Carnivora, being distributed across the entire northern hemisphere from the Arctic Circle to North Africa, Central America, and the steppes of Asia...
es and domestic cats.
Southwestern pygmy possums have the ability to enter torpor
Torpor
Torpor, sometimes called temporary hibernation is a state of decreased physiological activity in an animal, usually characterized by a reduced body temperature and rate of metabolism. Animals that go through torpor include birds and some mammals such as mice and bats...
during inclement or cold weather, enabling them to conserve energy and food reserves. During bouts of torpor, which may last for up to seven days at a time, body temperature falls to within one degree Celsius of ambient, and oxygen consumption to just 1% of normal. They sleep on their front, with their ears folded over their eyes, and the long tail coiled beneath their body. Compared with other mammals of similar size, they rouse from torpor unusually quickly.
Reproduction
Southwestern pygmy possums can breed throughout the year, although they do so more commonly in the spring, and give birth to litters of four to six young. Although the mother often carries more than six embryos at a time in her womb, because she has only six teats, and marsupial young remain attached to an individual teat for much of their early life, this is the maximum number she is able to rear. Unusually, however, the mother may give birth just two days after weaning a previous litter, with her teats dramatically changing in size to accommodate the smaller young, and the mammary glands reverting to production of colostrumColostrum
Colostrum is a form of milk produced by the mammary glands of mammals in late pregnancy. Most species will generate colostrum just prior to giving birth...
.
The young are still blind when they leave the pouch at around 25 days of age; they initially remain within the nest, and are fully weaned at around 50 days. Females reach sexual maturity at twelve to fifteen months.