What lays eggs, has no teats but suckles its young?
Closes its eyes and ears to search for food?
Has thicker fur than a polar bear, the bill of a duck and the tail of a beaver?
The Platypus is a facinating and unique animal called a monotreme – one of only three egg-laying mammals or monotremes in the whole world!
The little monotreme spends its days resting in burrows in the riverbank, emerging after dusk to feed in the water. They have such great appetites that they can eat their own body weight in food in 24 hours!
The Platypus’s amazing bill is not hard like a duck’s, but soft and leathery. With its eyes and ears closed, the Platypus uses its bill to forage for insects on the bottom of rivers and creeks. This bill contains electro-receptors which detect the tiny flickers of electricity given off by the creatures it feeds on. This gives the Platypus a ‘sixth sense‘ allowing to feed in the deep, dark water.
Often thought of as silent, Platypus can softly growl!
The Platypus has fur even thicker and denser than a polar bear’s – each square mm of platypus hide contains around 900 hairs!
The fur has two layers which trap air to keep the platypus dry when submerged. This gives the Platypus a silvery sheen when underwater. To remain waterproof in the water the platypus must have very clean fur, free from oil and other pollutants. The platypus will groom itself carefully using its bill and its hind claws.
Platypus are fantastic swimmers, using their webbed front legs for power and their back legs to steer. The platypus can remain submerged for up to two minutes at a time, allowing it to dive to around 5m to forage for food.
Male Platypus are typically 50cm long and weigh up to two kilos.
Female Platypus are typically 43cm long and weigh up to 1.5kgs.
Average life span for a Platypus is between 4-8 years, although they have lived as long as 17years in zoos.
Distribution & Habitat
Platypus habitats include rivers, streams and lakes along the East Coast of mainland Australia, including Tasmania. They are also occasionally found in South Australia. Platypus favour waterways with well vegetated banks, which allow for secure burrows to be built amongst the root systems of the plants. The trees also shade the water and leaves falling into the water and decaying helps to support the insects that the Platypus likes to eat. This vegetation is so important to the Platypus that there is a direct correlation between the amount of vegetation on the bank and the numbers of platypus in the area.
The hardy Platypus will make a resting burrow in a non-vegetated bank, however they will only make a nesting burrow in a vegetated bank. The nesting burrow is far more complex than the resting burrow, and needs the added structure of the root system.
The Platypus also needs a very specific type of waterway to feed in – it must be less than 5m deep (as the platypus can only dive that far) not have a strong current and needs to have trees close to the bank to provide shade and leaves falling into the water to feed the insects that the platypus eats.
Submerged logs and branches are also great for the Platypus, providing areas to rest and increasing the habitat of the tiny aquatic invertebrates that they feed on.
Platypus will breed in September and October.
Mating takes place in water. In the two weeks after mating and before she lays her eggs the female Platypus must prepare for the arrival of her young. All parental care is given by the female.
She will select a suitable location for her nesting burrow in the roots of a tree on a vegetated bank. She will locate its opening just above the waterline. The nesting burrow will be a far more complicated burrow than her usual resting burrow. While her resting burrow might be 4 -5 m long, her nesting burrow can be up to 20m long and contain twists and turns.
She will use her tail to collect leaves to make a nest in the end of the burrow. Before she lays her eggs she will seal herself into the burrow by blocking it at intervals with earth. This provides a safe place for her to incubate her eggs and raise her young.
Two weeks after mating two or three grape sized eggs are laid. The eggs have soft leathery shells like snake eggs. The female incubates the eggs by holding them between her body and her tail. The eggs hatch after two weeks of incubation.
The young will suckle thick nutrious milk directly from two patches of skin on the mother’s belly. The young will remain in the burrow for up to five months, while the mother leaves to forage. After five months the young Platypus will begin to follow the mother into the water to learn how to forage.
Platypus reach sexual maturity at two years.
Platypus feed upon tiny freshwater invertebrates including insects, beetles, yabbies, fish eggs and worms. While holding its breath the Platypus will forage along the bottom of rivers and streams. Using the electro-receptors in its bill the Platypus detects its prey, snaps it up into its bill and stores it in its cheek pouches. Once these pouches are full the Platypus will rise to the surface to grind the food between its upper and lower bill before swallowing it.
Platypus need to eat around 30% of their own body weight daily to survive. In lean times they can live off a reserve of fat stored in their tails.
The Platypus is the only Australian mammal known to have venom.The male has a 15mm long spur on its hind leg, through which the venom is passed. The venom levels increase during breeding season, possibly to fend off other males when fighting for breeding rights.
The venom is not dangerous to humans, however a spurring by a male can be very painful. Unfortunately, fear of being spurred means that some fishermen will not remove fish hooks from Platypus bills if they are accidently hooked. This usually means death for the Platypus due to infection. It is however possible to remove the hook without being spurred if the platypus is covered with a towel or jacket first.
The Platypus is classified as common, however populations are vulnerable. Platypus habitat has been effected by pollution, river damming, land clearing and live stock grazing. Inappropriate fishing methods and yabbie traps also effect population numbers.
Strain on our waterways directly effects the Platypus. Pollution from household chemicals, livestock and increasing salinity all have an effect.
Bank erosion and clearing has a huge impact on the habitat of the Platypus, as they need substantial vegetation to support the delicate balance of their habitats. The trees provide shade, oxegenate the water, provide food for the aquatic invetabrates that the platypus eat, as well as providing burrowing areas amoungst the tree roots. Stablisation and revegitation of banks will increase the habitat of the Platypus.