Meet Our Animals

Added to My Visit

This item has already been added

Did You Know?

Member Visitor Tips

Viewing Hints

The otters are most active between 10-11 am and at the end of the day between 3-5 pm. They enjoy napping mid-day when the weather's really warm!

Add to My Visit

Home > Meet Our Animals > Mammals > Carnivora > Giant otter

Giant otter

Pternonura brasiliensis

General Info
Our Animals
Conservation
For Kids

Size	Giant otters are about 6 feet long (1.8 meters) from head to tail.
Weight	Otters usually weigh between 60 and 70 pounds (27 and 32 kilograms). Males are slightly larger than females.
Conservation Status	On the 2011 IUCN Red List of Threatened Species, the giant otter is listed as Endangered.
Diet	Giant otters are piscivorous, meaning they mainly eat fish. In the wild otters commonly prey on medium sized fish such as trahiras, catfish, and perch. At the Zoo, their diet includes a variety of fish including tilapia, catfish, and rainbow trout. When the otters are rearing pups, catfish ,which has a higher fat content, is increased in the mother’s diet to support lactation. Wild giant otters frequently hunt catfish in the dry season, which corresponds to the time when pups are born.
Geographic Range	They are usually found in oxbow lakes and slow-moving rivers within the tropical rainforests of South America.
Where to find me in the Zoo	Carnivore Kingdom

Note: Description below should include Longevity, Behavior, and Reproduction information

“Lobo del Rio” or the giant otter is the largest of the non-marine otters and may be found only in South American river systems. They have a blunt, sloping muzzle with long vibrissae (whiskers) along with a ventrally flattened tail. Their flattened tail enables them to swim with great speed and maneuver easily underwater. The otters’ forefeet are shorter than their hind feet and each foot has 5 toes with sharp non-retractile claws and webbing that reach the tips of the toes. Their ears are small and round and like their nostrils, can be closed by special muscles when underwater.

A giant otter’s fur is so dense that the water never reaches the skin, even when swimming. Otter guard hairs trap air and keep the dense inner fur dry. The coat is mainly brown or gray is usually darker on the back and lighter on the chest, throat and undersides. On the throat is a uniquely shaped, creamy white patch, like fingerprints in humans. This unique mark allows us to identify each individual otter. Throughout Europe, Asia and America, otter pelts are such highly prized fashion items that by the middle of the 20th century, over-hunting almost let to their extinction.

Longevity

Giant otters may live into their late teens in a zoo setting, however a typical lifespan is 12- 14 years.

Reproduction

In March 2004, our female giant otter gave birth at the Philadelphia Zoo, the first North American zoo to have a successful birth. Unlike most otter species, giant otters living in the wild live in extended family groups (up to 10 per family) with strong bonds between breeding pairs. The female is the dominant partner in breeding pairs. Families usually consist of a breeding pair and their offspring which help the parents raise younger siblings. In the wild, young are born between August and October. Females have a gestation of 65-70 days. They may give birth to between 1 and 5 pups per litter.

Behavior

Giant otters are more vocal than the North American river otters. They have very distinctive sounds and complex communication. Researchers have been able to identify and describe individual meanings of at least 9 vocalizations. Giant otters are diurnal, or active during the day. They catch prey with their mouths and hold it with their paws while eating.

They will clear areas along the banks of lakes or rivers which they use for resting and grooming. Both female and male otters scent-mark their territory. Giant otters are member of the Mustelid family, which also includes weasels, skunks and ferrets. All the animals of the Mustelid family have strong scent glands.

Nina: Female, born at a zoo in Brazil on May 20, 2000. Received on breeding loan from the government of Brazil on October 22, 2002.

Nina has successfully raised 15 pups at the Philadelphia Zoo. Ten of those pups have gone to zoos across the country, including Jacksonville Zoo, Dallas World Aquarium, Los Angeles Zoo, Miami Metroparks, and Moody Gardens.

Five pups are still with their mom:
Bajo: Male, born June 21st, 2009
Canta’o: Male, born June 4th, 2010
Yeyuno: Female, born June 4th, 2010
Ariranha: Female, born June 4th, 2010
Thor: Male, born May 3rd, 2011

Enrichment

Adoption Information

Featured Foster Parent

Conservation at a Glance

Balbina Lake, Brazil: Giant Otter Project

Brazil is the largest country in South America both in terms of size and population. It is home to the majority of the Amazon rainforest, the most species-rich tract of rainforest in the world. The diverse group of species found there includes the giant river otter that live in slower moving rivers in the Amazon drainage basin.
Due to intense hunting for fur in the 1970s along with pollution and habitat loss, numbers in the wild dwindled. In 1999, with only a couple thousand individuals remaining in the wild, the giant river otter was classified as endangered.
Giant otters are susceptible to human disturbance. With increasing human activity in the Amazon, research is needed on the adaptability of giant river otters to these changing conditions.
The Philadelphia Zoo provides financial support for Dr. Fernando Rosas’s research on giant river otter behavior.
Dr. Rosas studies otters in the Balbina Hydroelectric Lake where they inhabit an area with human-constructed dams. His research will help document the effects of human presence on giant river otter populations and find ways to minimize impacts.
The Philadelphia Zoo was the first North American Zoo to have a successful giant river otter birth, in March of 2004, and currently is home to one of less than a handful of breeding pairs of giant river otters in the United States.

To learn more about the conservation efforts at the Philadelphia Zoo, click here.

Did you know the Philadelphia Zoo offers opportunities to travel around the world and get up close with certain animals? Learn more.

Zoo Research

Fun Facts

Giant otters will eat pirahnas, caiman and anacondas in the wild as part of their diet.
Giant otters can swim 330 feet (100 meters) in under 30 seconds.
River wolf is another name used in South America for giant otter.