What makes you a mammal? There are more than 5000 mammal species split into three groups. Each group has differences that make them special in their own way.
The most unique group of mammals are the monotremes. Laying soft shelled eggs, babies hatch out as a fetus.
Rather than teats, mothers feed the young through ducts on their belly. Only three species of monotreme exist today and two of these species are in Australia. Platypus and echidnas are the stars of this group. They lay eggs in nests where mum raises them to independence.
A slightly more diverse group are our (often) pouched friends - the marsupials. Kangaroos and wallabies are some obvious members of this group but possums, koalas, wombats and quolls all fit in here too.
Marsupials give birth to an embryo, much less developed than a human baby. The embryo has strong forearms that it uses to climb up to the teat where it attaches to develop.
Australasia boasts around 248 marsupials but about one third of living marsupials live in South America and only the opossum occurs north of Mexico. Our discovery of marsupials is ongoing with 50 new species described in the past 25 years.
The most diverse mammal group, to which you are intimately acquainted, are the eutherian mammals. We fit into this group.
Giving birth, eutherian mammals can range from a squishy pink undeveloped mouse to the extreme opposite. Wildebeest are born like miniature adults and can forage almost as soon as they are born.
These reproductive modes are wildly different, so what unites mammals together? In common to all mammals is the origin of hair, a metabolism to stay warm, and milk for nourishing young. This is different to many reptiles, fish and insects that may never interact with their offspring.
Nine of every ten land dwelling Australian mammals occur nowhere else in the world. Despite our spectacular range of monotremes, marsupials and eutherian animals, Australia has lost 10% of its mammal species since European invasion. To reverse this trend we need to invest in conservation and take climate change action seriously. At a pivotal point in history, we have the chance to save entire species. Join the petition to ask the federal government to declare a climate emergency today. https://www.aph.gov.au/petition_list?id=EN1041