Natural Histories

photograph of a Sunda Pangolin

Duck-billed Platypus

Ornithorhynchus anatinus


The duck-billed platypus has short limbs and a stream-lined, elongated body covered with dense, woolly, water-repellant fur. The fur can range in color from medium to dark brown along the dorsal side and brown to silver-gray on the ventral side. There are furrows along the sides of the head to protect the eyes and ears while swimming underwater. The ears of a duck-billed platypus have an external opening which is tubular and lacks pinnae. This species has a bill and webbed feet with naked soles (hind feet are only partially webbed), resembling that of ducks; the bill is soft, flexible, and leathery with nostrils located at the tip. The tail is flat and broad, resembling that of a beaver. Male platypuses tend to be larger than the females and have a sharp, grooved spur on each ankle. These spurs are connected to glands which secrete venom, used as a weapon when combating other males for females. This species has large claws for burrowing.


This species is an aquatic animal, living in burrows along the banks of lakes, rivers and even mountain streams. The duck-billed platypus is only found in the wetter regions of eastern Australia and Tasmania. Their burrows tend to be along steep banks, thick with roots, overhanging vegetation, reeds and logs. They prefer waters less than 5 m deep.

Feeding Behavior and Diet

Duck-billed platypus uses organs located in its bill to detect prey. These organs have sensitive receptors to detect weak electrical fields and tactile stimulation to sense their prey while digging under water. Duck-billed platypuses are omnivorous, consuming both plant and animal matter. The diet of this species consists mostly of aquatic crustaceans, insect larvae, and some plants. They also consume shrimp, fish eggs, and small fish.


This species is a monotreme, which is a mammal that lays eggs. Duck-billed platypuses have a cloaca through which both solid and liquid wastes are eliminated and eggs are also laid. Breeding season varies with each population. Males use spurs on their ankles to battle other males for females. These spurs are connected to glands secreting venom, to induce a painful wound when used in battle with other males. Males initiate mating but must rely on the willingness of the female to mate. Males grabs the tail of the female with his bill as she swims past, if the female is unwilling she will try to swim through obstacles such as logs to escape. If the female is willing she will remain near the male and allow him to grab her tail again if he drops it. The gestation period for this species is 27 days, followed by an incubation period of 10 days.  Females dig deep burrows, 20-30 m in length, just before laying 2-3 eggs. After the burrow has been dug the female then plugs the entrance and incubates her eggs for 10-12 days. This species does not have a pouch and must keep the eggs warm by curling their body around the eggs. Duck-billed platypuses have mammary glands but no nipples; milk is secreted onto the fur of the belly where young are able to nurse for five months. Young do not reach sexual maturity until they are 4 years old.

Months and Times of Activity

This species is solitary and if male territories overlap they will change foraging times to avoid interactions with each other.

Special Features, Stories, Relationships

•    The duck-billed platypus is one of five species of monotremes; mammals that are able to lay eggs.  (The other four are species of echidna.)

•    Young platypuses have molars or milk teeth, but adults are toothless, they grind their food between horny plates on the jaws.  The anterior plates are ridged to chop food while the posterior plates are expanded and flat for crushing.

•    The duck-billed platypus is the only species within the genus Ornithorhynchidae.

•    To read legends featuring this animal go to;

•    Children’s book featuring this animal: Platypus and the Lucky Day by Chris Riddell


Ojo, E. 2008. "Ornithorhynchus anatinus" (On-line), Animal Diversity Web. Accessed November 04, 2014 at