There are three sub-classes of mammals; placental mammals, whose embryonic young
develop in a placenta before being born, marsupials who give birth to far less developed young
which then either cling to the mother/or are carried in a pouch to fully develop, and monotremes which are egg laying mammals.
While placental mammals dominate the wildlife population
elsewhere in the world, marsupials are by far the most common sub-class of mammals in Australia
. Kangaroos, Wallabies, Possums, Koalas, Wombats and Tasmanian Devil are all well-known Australian Marsupials.
Kangaroos are perhaps the most well recognised of all Australian native animals. They belong to the Macropodiformes family which also includes Wallabies. The most distinctive features of this family are their large hind legs and short front legs, which with the help of their well muscled tails, creates their distinctive hopping movement. The Red Kangaroo, the largest of the family is also the largest marsupial in the world reaching a size of 2 metres tall and weight of around 85 kg when fully grown.
Possums are tree-living marsupials and belong to the Phalangeriformes family. Their size varies greatly between the various species, with a pygmy possum weighing only 7 grams, whereas a common ringtail possum can weigh the same as a housecat. Glider possums (including the sugar possum and squirrel gliders), are a fascinating type of possum which inhabit the forests of eastern Australia
. These possums have a unique membrane structure stretching from the forelimb to the back limb, enabling them to glide through the air.
Koalas, another tree dwelling marsupial, belong to the Phascolarctidae family and are well known for their diet which consists entirely of eucalyptus leaves (they even derive their water requirements from theses leaves), and their bear-like appearance. The closest relative to the Koala is another well known native animal, the Wombat. Wombats, from the family Vombatidae are similar to Koalas but live on the ground and eat roots and grasses. They have teeth much like those of rodents and powerful claws used to dig burrows. While most marsupials have pouches at the front, the Wombat has a pouch at the back.
The Tasmanian devil is the world’s largest carnivorous marsupial, and belongs to the Dasyuridae family. It has long been perceived as one of the most vicious marsupials in the world, but this perception is undergoing a change, as Australians have come to realise the importance of the Tasmanian Devil to Tasmania
’s eco system (as scavengers, they clear their territory of carcasses). Unfortunately, the species is now under threat of extinction due to Devil Facial Tumour Disease, which has been rapidly spreading throughout the Tasmanian Population
The Platypus and Echidna, both native Australian animals, are the only monotremes in the world. The Platypus is a duck-billed, egg laying amphibian animal, and is considered one of the most unusual animals on earth due to its combination of unlikely attributes. The echidna, a species of anteater is another egg laying mammal with hairy spikes and a tubular snout with a tongue that is built to capture termites rapidly.
of Placental Mammals in Australia
is entirely made up of bats, rodents and sea dwelling mammals.
The Grey Headed Flying Fox is one of the most common bats native to Australia
, and is also the largest, with a wing-span of up to 1.3 metres, and a habitat that covers the highest population
areas in Australia
(following the coast from southern Queenlsand to western Victoria
). This flying fox species is a member of the group of bats termed "Megabats" which use sight and smell to navigate. Microbats which use echolocation (commonly referred to as "sonar") are also present in Australia
An important thing to remember about native Australian rodents is that they do not transmit diseases, unlike the various introduced European rodent species found around the country. A unique and well known native species is the Spinifex Hopping Mouse. These mice inhabit the semi-arid regions of Australia
, and are well suited to their environment, living in burrows, with the ability to survive without drining water. These mice are mainly nocturnal, and are a species to look for when travelling in the Outback.
Although many marine species are migratory and therefore are not considered exclusively native species, there are many marine mammals that spend at least part, if not all of their lives in Australian coastal waters. An example of these is the Dugong, a large mammal which can be up to 4 metres long and weigh up to 900kg. They are the only species of herbivorous marine mammal, and live either alone or in small groups, and spend their whole lives at sea. Australia
is home to the largest population
of Dugongs in the world, found in the warmer waters surrounding the northern half of the country.