Giant Otter Size: How Big Are They Compared To Humans And Other Otters

Deepthi Reddy
Feb 29, 2024 By Deepthi Reddy
Originally Published on Nov 12, 2021
Edited by Lara Simpson
Giant otter standing on log
Age: 3-18
Read time: 6.3 Min

There are 13 species of river otters around the world.

Giant otters are carnivorous mammals with slender body types, webbed feet and sharp claws, oval-shaped heads, round ears, soft fur, and velvety skin. They have a muscular tail that helps in swimming and creamy white hair underside of the throat.

The giant otter species are the largest otters in the world. It is difficult to differentiate between giant male and female species as they have almost similar heads and body shapes. The average life span of giant otters is between 10-13 years in the wild.

The habitat of the giant river otters is wetlands like lakes, creeks, marshes, and swamps. Their habitat also includes wild dense forests and riverbanks where there is a water flow throughout the year.

If you like the giant otter facts, refer to Kidadl's other content. Can you have an otter as a pet? And are otters predators?

Which species are giant otters closely related to?

Another name of giant otters prevalent in Brazil is ariranha. In Spanish, it is called a river wolf or water dog. They are closely related to the other otter species.

This Endangered species is known for playful behavior; these animals enjoy sliding and playing in large groups. They have a huge appetite. The giant otter's typical length varies between 57-71 in (145-180 cm); the average is around 6 ft (1.8 m).

Giant otters are a species of South American mammals belonging to the Pteronura genus. It is the only member of the Pteronura genus.

Giant Otter Size Comparison To Humans

The giant otters are excellent predators as they have whiskers that help them detect the vibrations in the river bed to find prey very quickly.

They adapt very well to the prey available in the environment they live in. If fish is not available, they adjust themselves by eating small caimans or snakes. They consume about 10% of their body weight daily.

While resting, they wind up in kelp (algae seaweeds) to remain on the water surface. The giant otters are diurnal and very particular in cleaning the shrubs and plants around their territory.

The giant otter is the largest among all the otters globally, whose length reaches about 6 ft (1.8 m), which is relatively equal to the 6 ft (1.8 m) human size.

Giant Otter Vs. Otter Size Comparison

giant river otter

These giant otter species are social animals living in family groups and the young ones from multiple breeding seasons. Lets us know the sizes of different otters and comparison with that of our giant otter.

The giant otter's average length is 57-71 in (145-180 cm) with an average weight of 53 lb (24 kg). Males tend to be larger than female otters. The average weight of a giant male otter is 57-75 lb (26-34 kg), whereas a female weighs 49-57 lb (22-26 kg). The giant otter's weight is more than all the other otters in the world. Check below the weight and length of the other otters around the world.

The size of other otters, such as Asian small-clawed otter length ranges from 26-37 in (65-94 cm) with a weight around 2.2-11 lb (1-5 kg); this is the smallest otter among all the otters. The average length of male California sea otters is 48 in (122 cm), and their weight is around 64 lb (29 kg). Alaska otters' size is a bit larger than California otters. The length of male Alaska otters is about 58 in (148 cm), and average weight ranges from 60-85 lb (27-39 kg); whereas female Alaska sea otters measure 55 in (140 cm) and weight range from 35-60 lb (16-27 kg).

South American Giant Otter Size

South America is famous for its islands and abundant natural resources, forests, and waterfalls. Two species of otters, neotropical otters, and giant otters inhabit South American forests.

Neotropical otters range from Central to South America, whereas giant otters inhabit the Amazon forest range from north of Uruguay to Colombia.

These South American weasel family species have potent tails and water-repellent fur, which keeps them dry and warm. They eat fish as their primary diet; their other diet includes crustaceans and snakes. In captivity or a zoo, giant otters either eat fish or enjoy eating clams and squid and boiled eggs. They can hunt alone or in groups; although, they prefer to live in family groups.

The peak breeding season is between late spring and early summer. Though giant otters live both on land and in water, they burrow dens on the banks of rivers or places near the water and are highly territorial. Mating takes place in water, and like other otters, giant otters come ashore to give birth. The gestation period is between 65-70 days. The giant otters give birth to a maximum of six young ones at a time. The young ones are called cubs, are kept in dens in the initial weeks, and become independent within a year.

How big can a giant otter get?

The giant otters have also been named the river wolf and belong to the weasel family endemic South America.

It is not only the world's most significant otter in size but also the most prominent member of the mustelid family. It can grow around a length of 1.8 m (6 ft). Its length is twice the length of the Asian short-clawed otter, the world's smallest otter.

This otter is found in the Amazon, Orinoco, and La Plata, the three river systems.

How to identify the giant river otter? The giant otters are found in South America, Peru, Brazil, and Venezuela. It is a species found living in a group of up to 20 individuals. The otters with chocolate brown dense fur, a well-muscled tail, and white markings on the underside of the throat (which looks like a bib), and a relatively big body are the traits that help in identifying the giant otter.

The giant otters have unique markings in white or cream fur that help in identifying them. While meeting with one another, they show typical behavior known as a periscope, where they display their throats and chins for easy identification.

How big can a baby giant otter get?

Giant otters give birth in dens at riverbanks, which have multiple entrances and multiple chambers.

The reproduction peeks in the dry season. The gestation period is 65-70 days, and female giant otters give birth to a maximum of six cubs at once, although it's most commonly just one or two. The cubs are born blind.

Male and female otters actively take part in rearing the cub(s). A cub opens its eyes in the fourth week and starts walking in the fifth week. By the 14th week, the young giant otters can swim confidently. At two years of age, the young one gains sexual maturity. After this period, the cubs leave the parent groups and start living independently and building their own territory.

When born, each baby otter is tiny and weighs just around 1 lb (0.4 kg).

Giant Otter Conservation

Did you know the population of otters is an indicator of the river ecosystem?

Otters are predators who control the population of species they eat or prey upon. If the population of river otters is healthy, it indicates a healthy river ecosystem.

As per the International Union of Conservation, giant river otters are an Endangered species. The main threat for the giant river otters is habitat loss, use of pesticides, and pollution. The illegal trade for their fur is another threat to its life.

Jaguars and crocodiles might prey on young otters.

Here at Kidadl, we have carefully created lots of interesting family-friendly facts for everyone to enjoy! If you liked our suggestions for giant otter size, then why not take a look at what do otters eat or giant otter facts?

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Written by Deepthi Reddy

Master of Business Administration

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Deepthi ReddyMaster of Business Administration

With an MBA under her belt, Deepthi has discovered her true calling in content writing. Her writing repertoire is diverse, covering travel, movies, pet care, parenting, animals and birds, and more. Her joy of learning and creating has helped her craft well-written and engaging articles. When she isn't writing, Deepthi enjoys exploring new cultures, trying different foods, and spending quality time with her two children aged 7 and 12.

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