Otter vs Beaver – Any Differences?

Otters vs Beavers

If you’ve ever been confused about whether you’re looking at a Beaver or an Otter, you should know that you’re not the only one. Both the otter and the beaver share the same habitat and at a first look will be almost identical. This is why most people will usually confuse them pretty easily. Truth be told, in reality, Otters and Beavers are pretty different one from another, belonging to different orders, which makes them pretty different animals altogether.

If you want to know how to set them apart, this is a great resource to read. This article will give you information about all the differences between An otter and a beaver based on their appearance, diet, reproductive cycle, and so on.

So, what would make otters and beavers different?

Otters and Beavers are actually completely different, aside from the similarities in terms of their habitats. While Beavers are strict vegetarians and are considered semi-aquatic rodents, Otters are carnivorous mammals, considerably larger in size. Beavers are more similar to rodents, with a rounded body, while otters are more similar to seals, with glossy, slim, and long bodies.

Otters are about half of the size of Beavers and will only live half as long in the wild. They also have very different tails between them. Beavers have an oval-shaped, broad, and flat tail, while Otters would have a tail that is pointed and longer in size.

Both Otters and Beavers will mate based on a specific season, but the difference is that while Otters will look each time for a new partner, Beavers are monogamous and will stick to one partner. Beavers will have babies that are called Kits, which will be born fully matured, while the babies of Otters are called pups are usually born before reaching a fully-matured state.

You might also like my articles on raccoons, squirrels. or possums.

Differences between Otters and Beavers

Otters are part of the Mustelidae family and are considered 100% carnivorous mammals. This family is comprised of animals like weasels, badgers, wolverines, and minks. An even smaller categorization will place all different species of Otters inside the Lutrinae group.

Nowadays, just a few of all the subspecies of Otters have survived. Most of them have gone extinct, leaving only about 13 subspecies of otters alive around the world.

Beavers, on the other hand, are herbivorous, large rodents. They are considered the second rodent in the world by their size, after South Americațs Capybara. They are native to North America. These are the rodents known worldwide as lodge, canal, and dam builders.

Beavers, along with two other species, are categorized under the Castor genus. The Castor Californicus species have been extirpated, while the other two are extant and are known as the Eurasian beaver and the North American beaver.

It is a fact that Beavers and Otters share the same habitat. This isn’t enough to call them similar, as everything else about them differs. If you give the table below a read, you will find out the differences between these species in terms of physical features and basic lineage.

Animals Beaver Otter
Type Genus Castor Lutra
Class Mammalia Mammalia
Order Rodentia Carnivora
Family Castoridae Mustelidae
Subfamily Castorinae Lutrinae
Phylum Chordata Chordata
  1. Eurasian Beaver (Castor Fiber)
  2. North American Beaver (Castor Canadensis)
  1. Asian small-clawed otter (Amblonxy)
  2. Aonyx
  3. Sea otter (Enhydra)
  4. Speckle-throated otter (Hydrictis)
  5. Lontra
  6. Lutra
  7. Lutrogale
  8. Giant otter (Pteronura)
Extinct Species Castor Californicus
  1. Enhydriodon
  2. Algarolutra
  3. Cyrnaonyx
  4. Megalenhydris
  5. Sardolutra
  6. Siamogale
  7. Teruelictis
  8. Enhydritherium
  9. Lartetictis
  10. Limnonyx
  11. Lutravus
  12. Sivaonyx
  13. Torolutra
  14. Tyrrhenolutra
  15. Vishnuonyx
Average lifespan 24 years 12 years
Average weight 11-32 kg 7-12 kg
Average tail length 20-30 cm (7-12 inches) 30-50 cm (12-20 inches)
Average body length 135 cm (53 inches) 116-147 cm (46-57 inches)

There are some other differences between Beavers and Otters and I`ll go over each of them below, so don’t leave just yet!

Where did Otters and Beavers Get Their Names From?

The otter has been named after the old English term “oter” or “otor”. These terms were imported from the Proto-Indo-European dialect, where the term “wodr” was used. This word is believed to be at the base of the word “water” that we used today.

This name fits these creatures pretty well, especially considering that they are either semi-aquatic or aquatic, depending on their species.

The name of the beaver, on the other hand, will find its origins in the old English terms “beofor” or “befer”. These were also taken from the Proto-Indo-European language, being associated with the term “bhebhrus”, which can be translated in either “bright” or “brown”. This is also a pretty suitable name, considering that Beavers have brown skin.


Their faces

Most people consider Otters very cute animals. These creatures will look very similar to seals, at least to the inexperienced eye.

They have a very small face, with thin whiskers, and really black eyes on its sides. Instead of normal ears, they have holes with some upper skin.

A beaver will have a different type of face, more similar to other rodents. They have hair around their nose that is lighter than any other hair on their body, and their eyes are black and small.

They have more normal-looking ears, more prominent than those of otters, placed right next to their eyes.

Their teeth

You will know you’re seeing an Otter when you notice those two sharp teeth that protrude from their lower jaw. Between them will be an easily noticeable gap. On the other hand, beavers also have two big teeth, but these are almost conjoined, coming from their upper jaw, with a somewhat orange color.

With the help of these two teeth, Beavers will easily cut through most types of wood. The ears and nostrils of Beavers will be closed and their eyelids will be see-through, enabling them to swim very comfortably.

Their bodies

In comparison to the rest of their slim and long body, Otters have very short limbs. They have fur that covers all of their body, including the head, and is glossy, and brown. To help them swim easier, all of the four feet of the otter have webs between the fingers.

The beaver is covered in brown, thick fur, and its body will be round like in the case of most rodents. When put next to each other, the Otter will look hairless in comparison to the beaver.

The forelimbs of the Beaver have a claw-like shape, while the back limbs are webbed. You will mostly see these rodents on their hands when they are on the ground.

In terms of the species’ average body weight, Beavers are usually considerably heavier than Otters. The average weight of the Otter will be anywhere between 7 and 12 Kg, while beavers weigh around 23 Kg.

The heaviest species of Otter in the world is the Sea Otter, and it weighs around 20 Kg, this also being the closest in terms of weight to Beavers.

Their tails

Both these animals have a long tail, anywhere between 30 and 50 cm long, which is a feature that you will surely remember. Except for the Sea Otter, all other otters will have a long and muscular tail, great for swimming. Beavers will usually have a tail that is oval-shaped, flat, broad, and covered with black scales, completely different from what Otters have.

Their diet

Beavers are devout herbivores, with a strict vegetarian diet, that they will keep their entire lives. On the other hand, otters are fully carnivorous animals.

Otters will usually be found in water, where they spend most of their lives. This means that their diet will be comprised of mostly fish and water creatures. This includes frogs, crabs, and crayfish.

When out of the water, Otters will also eat birds or small mammals that they can find close to their habitats. Some of them can even open shellfish and eat them.

Sea otters are a little different, being able to also prey on creatures like snails, mussels, abalones, sea urchins, and clams. The continuous decrease of aquatic life in their habitats is a serious issue for their well-being, considering that this is what makes up for most of their diet.

On the other hand, Beavers have a considerably easier life as vegetarians. They will always find vegetation to munch on. They will eat any combination of aquatic plants, the bark of trees, twigs, foliage, fruits, and leaves. The inner bark from trees is what they like to eat the most.

The bark of trees will be mover half of everything they would eat during the winter months. When summer comes and they can find a lot of plants that they like to eat, they will only keep eating a small amount of bark, along with a combination of plants and fruits. Beneath the tough upper layer of any tree bark, there will be cambium, a real treat for beavers that will chew it all day long.

Beavers also like to eat the foliage of aspen trees, willow, and red maple. They will also eat a combination of cattails, bulrush, leaves, grass, ferns, water lilies, rhizomes, and pondweeds.

Their reproduction

Otters Vs Beavers CartoonThe location of the habitat as well as the individual species will dictate the specific mating season of Otters. When reaching the age of 2 to 3 years, Otters will become mature and ready to reproduce, regardless of their gender.

They will usually mate more than once each year if the shelter, food, and natural habitat provide the necessary conditions. They will only get together during the mating season and will prefer to stay males with males and females with females for the rest of the year.

Female otters will roll around with the males as a sign that they are ready for mating. Otters prefer to mate in water, although they will do most of the courting on land.

The pups are born usually after a gestation period that can last anywhere between 2 and 9 months. One litter will have a maximum of 6 new pups, although most of the time the females will only give birth to a single pup.

The Beavers are known to be strict monogamous creatures. A beaver will wait for its partner to die in order to even start looking for another one. They will be mature and ready to reproduce at around 3 years old.

They have a breeding season that is set between the first two months of each year. They have a shorter gestation time, of just around 120 days, and each female Beaver will be able to give birth to around 4 kits each time.

Their offspring

Otter pups are born blind and will need about one month to gain their eyesight. They will usually be born either in a den or on a kelp bed in the water, where they will be kept until they gain their sight. If the pups are born on land, the mother will try to move them into a den.

As soon as they gain their sight, their mother will want to teach them how to swim. For baby otters, is the mothers that are full-time caregivers. The otter parents will be able to mate again as soon as the pups are born, but they will usually wait around one year, while they nurse the pups.

It’s only in the event that its pups die, that the female otter will consider getting pregnant again as soon as possible. Although most otter species will have mothers that would nurture the pups for around 12 months, there are a few types of otters that will reduce this period to about 8 months.

The Beaver babies are also known as kits. Kits are born fully mature, with functioning and open eyes, and thick fur on their bodies, unlike Otter pups.

It shouldn’t take more than one day for them to get in the water and learn to swim. In a maximum of 2 weeks, they will be completely independent. They will continue to stay around their parents for the next 2 years, after which they will start their own lives.

Final words

Experienced individuals will agree that there aren’t a lot of similarities between otters and beavers. Beavers are a type of rodent, while otters are mammals.

Beavers will only eat plants, while otters are strictly carnivorous While Otters will like to change their love partners quite a lot, Beavers are known as monogamous.

And there are a lot of other things that make them different, as explained above,

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