The Platypus –

just one of Australia’s many weird animals

Photo by Ronald Bradford on Unsplash

First of all, a sonic-boom-like shout-out to Susan R.-T. who generously signed up for a “Founding” subscription! The only one, and I never thought this would EVER happen. She’s a dear old friend who I have known for – what – about 40 years? So, a HUGE thank-you, Susan!

A recent Guardian article about the oldest platypus found in the wild had me wondering: Why are there so many strange animals in Australia? And nowhere else on the planet? Creatures such as marsupials, aka pouch-baby species. There are some 330 known species in the world, and two-thirds of them live in Australia. Or the monotremes: a unique group of mammals that lay eggs. Only four living species belong to this group, and the platypus is one of them. But first, a quick look at Australia’s geological history. 

Continental Drift Encyclopedia Britannica

Some 180 million years ago (the late Jurassic Age) a huge landmass called the Gondwana Supercontinent began to split apart  because of plate tectonics and continental drift. Slowly, it broke into what we recognize today as Africa, South America, Australia, Antarctica, the Indian subcontinent and the Arabian Peninsula. By  about 30 million years ago Australia had fully separated and its flora and fauna evolved in isolation from the rest of the world. More than 80% of its plants, mammals, reptiles and frogs are unique to Australia and are found nowhere else.

Let’s stop for a moment – isn’t it totally amazing to realize that we’re not living/walking/standing on firm ground, but on thin plates that float on a mass of liquid, fluid  iron and nickel (mostly), the Earth’s outer core.  

Diagram of the Earth by Kelvinsong Creative Commons

Actually, that’s not entirely correct. We live on the Earth’s crust which makes up less than 1% of our planet’s radius and volume. The crust sits on top of the  lithosphere which is part of the Earth’s mantle – the layers that separate it from the liquid outer core. The lithosphere is subdivided horizontally into tectonic plates and they do move –  albeit v e r y  s l o w l y. 

Cutaway diagram of Earth's internal structure (to scale) with inset showing detailed breakdown of structure (not to scale) Public Domain

Just one other peculiar fact before we return to Australia’s peculiar creatures, including the platypus: the inner core of our planet is solid. Its temperature is estimated to be between 9,300 °F and 10,754 ± 900 °F… Too astronomical to fathom.

Here are a few of Australia’s bizarre and fascinating animals: 

Tasmanian Devil. Credit: The Maria Island Walk

What a cute little devil! Actually, it’s a marsupial, Mom can carry up to four babies in her pouch. Although they once lived in mainland Australia, they can only be found on the island state of Tasmania. Habitat loss and a cancer-like, highly transmissible disease called Devil facial tumor disease which first manifested around the 1990s means that they are classified as endangered. Several researchers and NGOs are working with the Tasmanian government to develop a vaccine and find other ways to ensure the survival of the Devils.

Wombat. Image credit: Michael Jerrard

Wombats are nocturnal marsupials that dig extensive, elaborate burrows with different tunnels and different entrances,  where they spend most of the daylight hours. The females’ pouches face backwards, towards the rear, so that dirt won’t get into the pouch when the animal is digging. I bet the baby wombats, or joeys, appreciate this – they stay in their mother’s pouch for six to ten months before they venture forth on their own. But the strangest feature about wombats is their poop: it’s square!  This has to do with the way they digest their food, and they use these squares to mark their habitat. A round dropping would roll off, but a square is more likely to stay in place – how cool is that!

Smiling Quokka. Image credit: Tourism Australia

The Quokka, a sweet little (about the size of a cat) marsupial, belongs to the family of macropods which means it’s herbivorous and has large hindlegs and a muscular, strong tail. A female quokka can give birth twice a year, each time to a single joey who lives in her pouch for six months. Their numbers are in decline though; climate change resulted in a much drier environment than what is comfortable for them. And frequent wildfires killed many of the animals. They’re classified as vulnerable, but are considered threatened. 

Photo by Michael Jerrard on Unsplash

And finally, we get to the platypus. Talk about weird things! How else can you call a mammal who lays shelled eggs. This group of animals is called monotreme and there are only two kinds left on earth today: the duck-billed platypus and the echidna, or spiny anteater. The name for the group comes from Greek and means “single opening”. Unlike other mammals but similar to reptiles, birds, and amphibians they have only one opening for their urinary, digestive, and reproductive functions. Mama Platypus usually lays two eggs in a nest she crafted, and incubates them for about ten days. When the babies (called “puggles”!) are hatched, they’re still vulnerable and blind, and rely on their mother’s milk which they receive through the pores of her skin. They stay with her for about three to four months; after that, they can survive on their own.

Infographic of Platypus electrolocation. Image credit: Chiswick Chap, Creative Commons

Platypodes are great swimmers, they have webbed feet and steer underwater with their beaverlike tail. A skinfold covers their ears and eyes, and they can seal their nostrils – that way, they can stay underwater for almost two minutes. With their bill, they scoop up worms, larvae, shrimp, and insects from the bottom of a riverbed. Another unique feature of the bill: it is capable of electroreception, which means that it is able to sense electric impulses emitted by its prey. Platypuses can accurately locate their prey and determine their distance from it – an amazing feat!  

I’ll mention one other rare characteristic of the platypus: it’s one of the few species of venomous mammals in the world. The male has a spur on his hind limb with a sting which can be fatal for smaller animals and is a useful defense against predators. 

While their usual lifespan is considered to be around 17 years in captivity and about 11 for wild platypuses (they’re highly elusive critters), one specimen who was found and tagged in November of 2000 when he was one year old, was recaptured last September, when he was about 24. This makes him the oldest known platypus, but there is a 30-year-old female who was born in the wild but now lives in captivity, a safer environment. 

The platypus is categorized as “near threatened” by IUCN, but listed as endangered in South Australia. Blame the usual suspects: climate change, drought, loss of habitat because of land clearing and changing water resources. We can only hope that this unique creature will be saved from extinction.