Porcupine vs Echidna – What’s the Difference?

Written by: Cameron Ward

Published: 06/26/2024

Reading time: 3 mins

Australia is home to many fascinating native mammals, one of which is the echidna.

Echidnas can be found roaming  around the mainland of Australia, Tasmania, Flinders Island, King Island and Kangaroo Island. When you see an echidna, you’ll notice its spiky quills. So you may be wondering, are echidnas related to porcupines?

It may surprise you to know that echidnas are not related to porcupines. Their closest living relative is actually the platypus. Who would have thought?

Differences between echidnas and porcupines


Now that we know that echidnas and porcupines aren’t related, let’s uncover what makes them different.

  • Type of mammal

One of the biggest differences between echidnas and porcupines is that they are different types of mammals. Porcupines are rodents, while echidnas are marsupials.

Rodents are the largest mammal group and they are characterised by their continuously growing incisors. Surprisingly, about 40% of mammals fall into the rodent group.

On the other hand, there are a few factors that classify marsupials. A marsupial is small at birth due to a short gestation period. They also have pouches where they protect their offspring while they develop. Additionally, they don’t have a corpus callosum, a part of the brain that connects the left and right cerebral hemispheres.


  • Their Spines

Both porcupines and echidnas have sharp spines, but there are some differences. Echidna spines are shorter. Also, porcupines can eject their spines. This means that if a porcupine is attacked, their quills will easily detach and stick into the predator’s skin.

  • How They’re Born

Porcupines are born like most other mammals. They develop in the uterus and are born after a specific gestation period.

The echidna is a rare type of marsupial called a monotreme. That means that it’s a mammal and lays eggs. In fact, the only other monotreme is the platypus. The egg will hatch within the  mother’s pouch and then the baby echidna will stay in the pouch until it’s ready to explore on its own.

  • Different Sizes

Porcupines vary in size since there are 18 different varieties of these mammals. They can range anywhere from 1 kilogram to 27 kilograms. They also range from 60 to 90 centimetres long, with tails as long as 20 to 25 centimetres.

Echidnas don’t vary as much in size, as there are only 4 different species. They typically weigh around 3 to 4 kilograms and can measure 30 to 45 centimetres long. They also have long tongues, which are around 15 to 18 centimetres long!

  • Type Of Diet

Porcupines are herbivores, which  means they mostly eat plants. They will eat plant matter and vegetables, but during the winter they may eat twigs and bark.


Echidnas basically eat anything. Their short beaks allow them to dig around in the ground to find insects. Because of this, they mostly eat ants, termites and worms. They also have a great sense of smell, allowing them to easily find food.

Now that you’ve learned all about these fascinating critters, you’ll be an expert when you see an echidna on Kangaroo Island!

Cameron Ward
Cameron Ward
Managing Director at Sightseeing Tours Australia

Cameron Ward turned his travel passion into a thriving Australian tourism business. Before he co-founded his own business, Sightseeing Tours Australia, he was enjoying being a Melbourne tour guide. Even now, Cameron delights in helping visitors from all around the world get the most out of their incredible Australian trip. You’ll see Cameron leading tours or writing about his favourite Australian places where he shares his local insights.