Difference Between Beavers and Otters (With Table)

Otters and beavers belong to class Mammalia in biological classification. Beavers are large, herbivorous, semi-aquatic rodents found in the northern hemisphere’s temperate climate. They are considered as the second-largest living rodents after capybaras. These mammals belong to the order Rodentia and genus Castor. There are two living species of beavers, the North American beaver (Castor canadensis) and the Eurasian beaver (Castor fibre).

Otters are furry, carnivorous animals of the Mustelidae family to which the weasels and badgers belong. They are semi-aquatic, aquatic or marine and known for their playfulness especially when in the water. They are found everywhere in the world except Australia and Antarctica. There are currently 13 living species of otters ranging from smooth-coated (Lutrogale perspicillata) otter to the giant otter (Pteronura brasiliensis).

Beavers vs Otters

The difference between the beavers and otters is their mode of nutrition which affects their behaviour also. A beaver is a herbivore while an otter is a carnivorous mammal.

Comparison Table Between Beavers and Otters

Parameters of ComparisonBeaversOtters
OrderRodentiaCarnivora
Mode of nutritionHerbivoresCarnivores
Time partitioningNocturnalDiurnal
RegionsNorthern hemisphereEverywhere except Australia and Antarctica
BehaviourHardworking, territorial and live in a close-knitted family.Playful as they love splashing in the water and gambolling on the land.
MoultingBeavers moult during summer.Otters do not moult
IUCN Red list statusLeast concernedEndangered

What are Beavers?

Beavers are the large, semi-aquatic rodents of the temperate northern hemisphere. They have stout bodies with large heads and can range from 80 cm to 120 cm in body length. Long chisel-like teeth help them cut down the trees and in digging. Their front feet resemble hands and help in manoeuvring their surroundings. They are semi-aquatic and thus have webbed back feet, flat scaly tails and waterproof fur. Their colour may range from reddish-brown to almost black. They are herbivores and eat tree bark, aquatic plants, brush (scrub vegetation), grass and sedges.

Habitat

Beavers live in freshwater habitats like rivers, streams, lakes and ponds. They are good builders and affect their environment by building structures like dams and lodges. They use things from their environment like tree branches, vegetation, rocks and mud to create these structures.

Because of their impact on the environment and other species, they are classified as keystone species.

Lifespan

Beavers can live up to 7- 8 years in wild and 24 years in captivity.

Behaviour

Beaver families have so much common with human families. Adult beavers live in monogamous pairs with their young ones. Adults build structures and feed the young ones. When parents are old, young beavers help parents build the structures and even help in raising younger siblings – just like humans.

Highly territorial- Beavers are highly territorial and even mark their territories using scent mounts made of mud, debris and castoreum (a substance excreted in urine through their castor sacs).

Beavers are good swimmers.

Nocturnal- Beavers are mostly active during the night. They sleep for almost 11 hours a day.

Concerns

Beavers are hunted for their fur, meat and castoreum which is used in medicine, perfume and food flavouring. In the 19th century, they almost got extinct but their population bounced back and now they are listed as the least concerned in the IUCN Red List.

What are Otters?

Otters are the adorably charismatic members of the Mustelidae family of members such as weasles, badgers and ferrets etc. Small, elongated sized otters have a head-body length of around 60 cm to 180 cm. They have short ears and noses which they can close underwater. They have dense fur and long rudder like tail.

Habitat

Otters live in freshwater habitats like rivers, lakes and wetlands. Some species have adapted to live in the oceans also, such as the sea otter and the smaller marine otter. They do not build their own homes but use structures build by the beavers and other animals to give birth to their young ones.

They have webbed feet and a powerful tail make them a great swimmer. Their waterproof fur keeps them warm. This fur does not have a fatty layer but it is the thickest of any other animal (a million hair per square inch). Some cold water species of otters have high metabolism rate which keeps them warm in the water.

Lifespan

They generally live around 16 years in the wild and can live up to 24 years in captivity.

Behaviour

Excellent hunters – Apart from being good swimmers, they are excellent hunters and hunt small fishes, crustaceans and other critters. They have highly sensitive whiskers which can detect the slightest change in the current and help them locate the fish. Some other species like the sea otter have learned to open the shellfish. The sea otter keeps swimming on its back and hits the shellfish with the stone till it gets open.

Otters are very playful unlike the busy beaver and love splashing, hoping and running around.

Diurnal – Otters are mostly active during the day.

They use their vocals to communicate.

Concerns

Otters are listed as an endangered mammal in the IUCN Red List because of massive hunting for their fur. They are also getting affected adversely by pollution and pesticides.

Main Differences Between Beavers and Otters

  1. Beavers are herbivores and otters are carnivores.
  2. Beavers are nocturnal and otters are diurnal.
  3. Beavers are found only in the temperate regions of the northern hemisphere while otters are found everywhere in the world except Australia and Antarctica.
  4. Beavers moult during summer but otters do not moult.
  5. Beavers are famous for their industriousness and busyness while otters are famous for their playfulness.
  6. Beavers are currently listed under the least concerned category in the IUCN Red List while otters are listed under the endangered category.

Conclusion

Otters and beavers are both adorable furry creatures having many similarities and great differences. Both of these mammals are hunted for the satisfaction of human greed. Challenges like climate change, global warming and industrial pollution are also affecting their population badly. Beavers have come over the danger of extinction in the 19th century and their population is stable now but otters are endangered today and we must ensure that they are protected.

References

  1. https://pdfs.semanticscholar.org/65e9/c16f5224532aff12ee87b673d39fba8aac59.pdf
  2. https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2907.2005.00067.x
  3. https://pubs.er.usgs.gov/publication/70189969