Penguin babies, called “chicks,” are covered in fuzzy down feathers which help to keep them warm. They look quite furry – but this isn’t fur – it is feathers. Penguins share many observable traits found in other birds as well. They have beaks, wings, lay eggs, have feathers, and incubate their eggs.

The Biological Species Concept defines a species taxon as a group of organisms that can successfully interbreed and produce fertile offspring. According to that concept, a species’ integrity is maintained by interbreeding within a species as well as by reproductive barriers between organisms in different species.

Because of evolution and the related nature of all life, species don’t really exist in nature, the term is entirely subjective. In other words, a “species” is whatever humans say it is. For example, the “biological species concept” says a species can only form viable offspring with itself.

Penguins are carnivores: they feed on fish, squid, crabs, krill and other seafood they catch while swimming. During the summer, an active, medium-sized penguin will eat about 2 pounds of food each day, but in the winter they’ll eat just a third of that.

In Australia, though, marsupials continue to be very diverse, and are the dominant native mammals. They include kangaroos, koalas (above left), tasmanian devils, wombats (above right), and other typical Australian mammals. Until recently, they also included the marsupial wolf, Thylacinus (below).

Big reds are the largest kangaroos and they can kill a dog if they get into a fight. Kangaroos are also very clever. If they are being chased by a dog, they will lead it into a dam, often resulting in the dog drowning.

“There’s a very strong instinct — kangaroos will go to water if they’re threatened by a predator,” kangaroo ecologist Graeme Coulson from the University of Melbourne says. “In the case of a big male, they can definitely drown dogs.

Contrary to popular belief, kangaroos don’t normally try to box, or punch, each other, says Festa-Bianchet. Instead, they prefer to balance on their strong tails and kick with their powerful back legs.

But, if we get too close, they may see us as a threat. Kangaroos and wallabies that are used to being fed can approach people expecting food. When there is no food, they may become aggressive. This means we can get too close to kangaroos and wallabies without thinking about the consequences.

“A male kangaroo can disembowel someone,” says Mr Piper. “They don’t set out to do it, but that’s the nature of how they fight: they kick with their big hind legs.” But people shouldn’t be frightened away. Coming close to them is usually safe – even petting a kangaroo can be OK, provided it approaches first.