Biodiversity Facts
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What is Biodiversity?
Biodiversity can be defined as the variety of all life forms, often considered at three levels: genetic, species and ecosystem diversity. That is, the variety within a species, between different species and across ecosystems.
Australia is known as a ‘megadiverse’ country, which means that we have a wide range of flora and fauna species, including a large amount of endemic species – over 80%!
Endemism means that a species is found only in one area or continent. This usually happens when an area is particularly isolated.
All the different plants and animals interact with each other, the earth and the atmosphere to form the web of life. The loss of species can affect other living species and can weaken the web of life. Once a species becomes extinct it is lost forever and a loss of species results in the loss of biodiversity.
The current rates of extinctions and the loss of biodiversity are the highest this planet has experienced in 60 million years.
Australia has seen severe declines and extinctions of native species populations in the past 200 years, especially in the last 50 years.
The loss of biodiversity is the most serious environmental problem we, as a species, face.
Want to find out more? Visit www.austmus.gov.au/biodiversity.
To learn which native species are found in your local area visit www.environment.gov.au/erin/ert/index.html and enter your postcode into the Environmental Reporting Tool.
Australia’s own biodiversity hotspot
The south-west region is Australia’s only “biodiversity hotspot” as recognised by Conservation International – a term that is both positive and negative.
With only 34 in total, biodiversity hotspots are home to an exceptional number of endemic species and have lost at least 70% of their original habitat. As such, many of the species native to this area are threatened with extinction.
Want to find out more? Visit www.biodiversityhotspots.org.
Australian Mammals
Mammals give birth to live young, have mammary glands that produce milk, keep a constant body temperature (endothermic) and are covered with hair.
Marsupials are a type of mammal that have a pouch to shelter their young, such as kangaroos, while a monotreme is a mammal that lays eggs, such as the platypus or the echidna.
At present in Australia there are 358 native mammals recorded. Australian mammals include the kangaroo, wallaby, koala, possum, numbat, wombat, echidna, quoll and lesser known mammals such as the Chuditch, Dibbler and Sandhill Dunnart.
Did You Know?
- Baby echidnas are called puggles and each spine on their coat is formed from a single hair.
- The Dibbler was thought to be extinct for 63 years! In 1967 a pair was collected by chance from Cheyne Beach on the south coast of Western Australia. The Dibbler used to be widespread in this area but now only small numbers have been identified in two isolated locations.
- Koalas spend up to 20 hours a day sleeping and resting, but they’re not just lazy! Their diet of eucalyptus leaves are not very nutritious and are high in toxins, so this is how they conserve energy.
- Rottnest Island, off the Western Australian coast, was originally named by the Dutch and means “rat’s nest,” reflecting the explorer’s description of the native Quokka species.
- Dingos are canines like domestic dogs but they do not bark, only breed once a year and they lack the distinctive “dog smell” of domestic dogs.
Australian Birds
Birds are uniquely adapted for flight, with feathers, wings and light skeletons, though not all birds can fly, such as the Emu and Little Penguin. Like mammals, they are endothermic which means they regulate their own body temperature.
As they do not have teeth, birds cannot chew food. Instead they have a gizzard, a special grinding organ located in the stomach that crushes the food.
Australia is home to many birds (over 700 different species), including parrots, birds of prey, waders, waterfowl, songbirds and rare species such as the Bush Stone Curlew and Star Finch.
Did You Know?
- Brolgas engage in dramatic “dances” involving leaps, head shaking and loud trumpeting to court and bond with their partner.
- A flightless bird, the Emu can reach speeds of up to 48 kph. The undersides of their three toes are flattened to help with traction over rough terrain.
- The Wedge-tailed Eagle is the largest bird of prey in Australia and among the largest in the world. Groups of Wedge-tailed Eagles may hunt together and even kill quarry as large as a kangaroo.
- To establish its territory, the Palm Cockatoo beats a hollow tree with a stick and will try several sticks until it finds the ideal sound.
- Owls are nocturnal and rely on heightened sight and hearing to hunt in the dark. Some owls have special feathers that enable them to fly silently when hunting.
Australian Frogs
Frogs are amphibious, which means they live on both land and water, breathing and taking water in through their skin. They are ectothermic – their body temperature is determined by their environment.
Frogs lay eggs and go through a tadpole stage to reach maturity.
Frogs are the only amphibians that are native to Australia and currently there are 216 recognised species. Australian frogs include the Motorbike Frog, Splendid Tree Frog, Chirping Froglet and Wailing Frog.
For more information on Australian frog species visit www.museum.wa.gov.au/frogwatch or www.frogsaustralia.net.au/frogs.
Did You Know?
- The Sunset Frog from south-west Australia, named for its unique colouration of a dark-purple or blackish back and flame orange underbelly, was only discovered in 1994.
- The Green Tree Frog is a natural insect repellent. The secretions from its skin have been found to be lethal to blowflies.
- Frogs use their eyes to swallow! They retract their eyes into eye bulges located in the roof of their mouth to help move the food down their throat.
- The collective term for a group of frogs is an army, while a group of toads is called a knot.
- Frog eggs laid in open ponds have a darker patch at the top which filters out the sun’s ultraviolet rays to protect the developing tadpoles.
Australian Reptiles
Like amphibians, reptiles are also ectothermic and cannot regulate their body temperature. They have scales and regularly shed their outer layer to expose newer scales. This is known as moulting or sloughing.
Most reptiles lay soft shelled eggs while others give birth to live young, such as the Tiger Snake.
With over 860 species of reptiles, Australia is recognised globally for its reptile diversity. The Woma, Frilled Dragon, Pygmy Bearded Dragon and Perentie are among Australia’s reptile species.
Did You Know?
- Reptile scales are mostly made of keratin, which is also a component of human hair and fingernails.
- Snakes smell with their tongue. Snakes flick their tongue in and out of their mouth to collect chemicals in the air. They do this to locate and sample food and to find a mate.
- The Estuarine Crocodile is the world’s largest living reptile. It is also known as the Saltwater Crocodile but this name is misleading as it can be found in both freshwater and saltwater habitats.
- The temperature at which turtle and crocodile eggs are incubated determines the sex of the young. For turtles, warmer temperatures produce females, cooler temperatures produce males and moderate temperatures result in a mixed clutch. This is the opposite for crocodiles.
- The Rough-scaled Python was only discovered in its limited Kimberley habitat about 30 years ago. This non-venomous constrictor curls its body into an S-shape and strikes when feeling threatened.
Why is Australia’s biodiversity threatened?
Human population growth is the greatest threat to biodiversity because as our population grows we need more resources, create more pollution and require more space. In turn, this puts pressure on native species and ecosystems as habitat is altered through land clearing for agricultural, commercial or residential purposes and by over harvesting our natural resources which includes livestock and water.
Global warming is caused by increasing levels of carbon dioxide and similar gases released into the atmosphere. This affects all species as they are specifically adapted to their environment – even small changes can have big repercussions.
Introduced species such as foxes, cats and rabbits also have dire effects on native species and habitat. Australia has approximately 25 species of exotic animals that have become established in the wild.
Exotic or feral species displace our native animals and compete with them for food and habitat. They may also predate our native species and spread harmful diseases. Animals such as wild pigs alter the environment with their hooves. There is no ecosystem that is untouched by at least one feral species.
Nearly everyone would be able to identify an exotic species such as a tiger or a meerkat, but how many people could describe a Chuditch or a Tawny Frogmouth?
To help save our remaining unique native species, it is essential to raise community awareness of the existence of these animals and the threats they face through programs such as Tiwest Night Stalk.