Some FAQs

Platypus(3) - Sharon WormleatonThis section highlights some of the many interesting and surprising facts about the platypus: 

What is the plural of “platypus”?

This is perhaps the single most frequently asked question about the species. People feel that “platypi” doesn’t sound quite right, but what’s the alternative? According to our copy of the Australian Pocket Oxford Dictionary (Fourth Edition), the word “platypus” is derived from two Greek words meaning “flat broad foot”. Given that the plural of the Greek “pous” is “podes”, we conclude that – strictly speaking – the plural of “platypus” should be “platypodes”. However, given that “platypodes” has for some unfathomable reason never become popular, the dictionary goes on to say that the accepted plural is “platypuses” or (particularly in scientific and conservation contexts) “platypus”. By the same token, given that “rakali” (a.k.a. the Australian water-rat) was originally an aboriginal term for this animal, its plural in English is presumably “rakali” rather than “rakalis”.

Photo courtesy of Sharon Wormleaton

What is the correct term for a baby platypus?

When a juvenile platypus first emerges from its natal burrow (at the age of about 3-4 months), it is already fully furred, well-coordinated, and has grown to around 80% of its adult length. Because juveniles are not normally seen by people at an earlier stage of development, there has historically never been a need to adopt a special term for an infant platypus. This situation changed in 2003 when a captive female platypus succeeded in raising twin daughters at Taronga Zoo in Sydney. When asked by reporters how to refer to the new arrivals, zoo staff suggested using the term “puggle” – a word previously used to denote a baby echidna.

What is the collective term for a group of platypus?

In contrast to a pride of lions, a gaggle of geese or a herd of cattle, the platypus normally feeds on its own, though more than one animal may be active at the same time in a given spot. Accordingly, there has never been a need to refer to these animals as a collective unit, though (should such a need arise in future) we personally would favour using the term “paddle”.

Can a platypus be kept as a pet?

The platypus is a notoriously difficult animal to keep in captivity. These animals need a lot of food (equating to around one-fifth of their body mass each day in the case of males or females without young) and are also quite picky about their diet, preferring to dine on live aquatic invertebrates such as insect larvae, worms and crayfish. Feeding and exercise tanks need to be as roomy as possible (after all, a platypus’s home range typically extends for a kilometre or more in the wild), and the water must be kept clean and fresh by appropriate use of automatic filters or being changed each day. Adult males in particular can be dangerous animals to handle – although the venom delivered by spurs on the hind ankles is not considered to be life-threatening, it can cause excruciating pain and swelling that lasts for days. Sensibly, there is no place in Australia where a platypus can be legally purchased or kept as a pet.

Do platypus breed successfully in zoos?

Platypus were bred in captivity for the first time at Healesville Sanctuary in Victoria. The breeding female (named Jill) was originally brought to the Sanctuary in 1938, after being rescued by two men who found her trudging along a road. The breeding male (named Jack) was captured as a young juvenile in 1939, after being spotted swimming in a local creek. The pair was observed mating for the first time in October 1943 and produced a daughter (named Corrie) who was successfully raised to adulthood. Platypus did not reproduce again in captivity until 1998/99, when two juvenile males were hatched at Healesville Sanctuary, with one surviving to maturity. Since then, successful breeding has also occurred at Taronga Zoo in Sydney. Second generation breeding by a pair of zoo-bred animals occurred for the first time at Healesville Sanctuary in 2008/09.

Is the platypus good to eat?

We don’t know of anyone who has recently tried to dine on a platypus. According to Harry Burrell (a keen naturalist who wrote a book about the species in the 1920s), a letter published in the Sydney Daily Telegraph newspaper in 1923 reported that some miners ate one and found it to be “a somewhat oily dish, with a taste between those of red herring and wild duck”. Burrell also quotes remarks made by Richard Semon (published in 1894) that aboriginal people residing near the Burnett River in Queensland didn’t include the platypus in their diet because the meat had “an objectionable smell” – possibly related to the occurrence of scent glands near the base of the neck.

Has the platypus ever been hunted commercially?

The platypus was hunted for its fur until 1912, when it became protected by law throughout its range. Up to 2356 platypus pelts were sold annually in the Sydney market in the late 1890s, with some persons making their living in this manner. Fortunately, although platypus fur is luxuriously soft and dense, its use in clothing was limited by the fact that the platypus’s skin is quite thick and remains fairly stiff when processed. Platypus pelts were therefore mainly used to produce lap rugs and outer garments such as cloaks, with as many as 75 skins used to fabricate a single rug.

How long can a platypus remain underwater?

The platypus’s aerobic dive limit (the interval until oxygen stored in the blood and other parts of the body is depleted) is approximately one minute when actively swimming. By then switching to anaerobic metabolism, an animal can continue to swim underwater for an additional one and a half minutes before it has to breathe again.

If a platypus feels threatened in the water, it may dive and then hide under a submerged log or other structure. By staying immobile and dropping its heart rate to as few as 1.2 beats per minute, a platypus can remain underwater for as long as 11 minutes before it needs to resurface.

How long can a platypus survive out of the water?

There are really two different ways to answer this question. On the one hand, the platypus is an air-breathing mammal that routinely spends many hours each day snugly asleep in a dry burrow. For this reason, persons who unexpectedly have to care for a platypus for a short time (such as an injured animal awaiting veterinary treatment) should never keep the animal in a water-filled bathtub or tank, forcing it to swim when it mainly needs to rest. On the other hand, the platypus is adapted to feed only in the water. If a platypus’s freshwater habitat therefore dries up (for example, due to drought), the animal will starve to death unless it can somehow find a new place to live.

Can a platypus jump or climb?

The platypus’s front foot ends in a broad band of webbing that extends well beyond the end of its toes to assist swimming. This essentially makes it impossible for a platypus to grasp objects such as a tree branch. However, platypus are exceptionally determined creatures when it comes to scaling surfaces that stand in their path. They can scramble up steep rocky banks with aplomb, and one was filmed trying to escape from a round metal tank by wedging itself between the side of the tank and a vertical water pipe and propelling itself upwards like a giant inchworm.

It’s sometimes claimed that an elephant is the only land mammal that can’t jump. However, we feel quite confident that a platypus is at least as inept as an elephant when it comes to launching itself off the ground. This is partly based on how the platypus’s skeleton is constructed: the limbs extend horizontally from the body, so the chest and abdomen are actually in contact with the ground at low speed. Furthermore, the joints and ligaments which bind the platypus’s legs to its body are designed to facilitate rotational (as opposed to back and forth) limb movements. This means that the platypus can swim and dig very efficiently, but is poorly equipped to compete in any kind of track or field event.

Does the platypus’s appearance vary across its range?

The platypus’s shape and the colour of its fur and bill are remarkably constant across its entire range, from Queensland to Tasmania. However, animals do vary quite a bit in size, with animals inhabiting warm northern water bodies generally being smaller than those found in cooler southern rivers and creeks.

Does a male platypus look different than a female platypus?

Although a male platypus is generally both longer and heavier than a female platypus, a large female may be nearly as big as a small male living in the same area. A male’s reproductive organs are also normally tucked up inside his body, so they can’t be easily used to distinguish males from females. The only really reliable way to tell whether a platypus is a boy or a girl is to examine the inner ankles of its hind legs: a male will be equipped with a conspicuous spur, about the size and shape of a medium-sized dog’s canine tooth. Females lack these structures, though juvenile females have small vestigial spur sheaths which are shed before maturity.

Does the platypus use gravel to help mash up its food?

It’s true that the platypus sheds its teeth soon after it starts eating solid food, and also true that bits of mud or sand are sometimes found mixed with the remains of edible prey in the animal’s cheek pouches (used to store prey temporarily while the platypus swims underwater). However, there’s no reason to believe that this inedible material is anything other than an inconvenience that’s been ingested by accident. After losing its teeth, the platypus grinds up its prey using rough pads located at the back of its jaws. The grinding pads are made of keratin (the tough structural protein found in the hair, claws, horns and hooves of other mammals) and can reduce aquatic insects, freshwater shrimps and worms to a fine paste without any help needed from other abrasive agents.

Does the platypus have a stomach?

The platypus’s digestive tract includes a small expanded pouch-like section where one would normally expect a stomach to be found. The stomach doesn’t secrete digestive acids or enzymes, though it does contain Brunner’s glands (which produce a mucus-rich fluid to assist nutrient absorption). Following on from the discussion of grinding pads above, it would seem that platypus food is masticated so well in its mouth that there’s no need for much more pre-digestive processing to occur before the food reaches the intestines. In addition, because a platypus consumes small mouthfuls of food at intervals of 40 seconds or more over a feeding period lasting many hours, there’s no need for its stomach to have a large holding capacity to accommodate large but occasional meals.

How deadly is platypus venom?

Platypus venom causes extreme pain and localised swelling in affected human limbs, but isn’t considered to be life-threatening to people. Although it’s often stated that platypus venom can kill a dog, there’s no convincing proof that this has ever occurred. When we checked the historical records (all dogs known to be affected by venom were spurred while retrieving a platypus from the water after it had been shot to provide a pelt in the late 1800s), it turns out that this conclusion is based on testimony from one retired hunter, who claimed that four of his dogs (plus more belonging to his brother) died this way. In contrast, a different hunter reported that his dog survived being spurred on three occasions, with the effects becoming less severe each time. In each case, the dog’s head (the part of the body that had been spurred) became tender and swollen. However, the swelling disappeared in 36, 10 and 3 hours and no lasting ill effects were apparent. Two other accounts of dogs recovering after being spurred have also been recorded.

In laboratory trials, rabbits and mice injected with platypus venom showed only mild effects when venom was injected under the skin, but died when it was injected directly into a vein. We conclude that platypus venom could kill a dog if the platypus happened to inject a substantial amount of venom directly into a major blood vessel. Otherwise, the dog is expected to experience pain and swelling, but should fully recover.