Giant otter

Giant otter populations are in decline due to habitat loss and overfishing. You can help by choosing sustainable options when buying seafood.

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Male giant otters can grow up to 6 feet long, and females can grow up to 5.5 feet long. Adults weigh about 50 to 70 pounds. Giant otter tail length is around 22 inches.
Their coats are dark brown with several white or yellow patches on the throat and chin. The pattern of these patches is unique to each individual and is used by researchers to identify individuals.
Dense, water-repellent fur helps keep their skin totally dry even while swimming. Other adaptations that aid in swimming are webbed feet, as well as ears and nostrils that close in the water.
Long whiskers help giant otters detect potential prey and determine water current changes. They have strong jaws and very sharp teeth. These assist the otters in catching fast-moving fish. They eat the fish whole, chewing up scales, spines, bones and all.

Wild – Primarily fish such as catfish and perch; Giant otters will occasionally also eat small snakes (juvenile anacondas), small caimans, crustaceans, amphibians, mammals and birds.
Zoo – Fish (trout, tilapia, catfish, smelt, butterfish)

Mating season usually occurs in late spring and early summer. However, there have been cases of breeding occurring throughout the year.
The gestation period is about 65-70 days. Females can give birth to one to five pups (usually two to three). Pups are typically born during the months of August through October.
In the wild, males are not involved in pup rearing and are only reintroduced to the pups once they are active and have started swimming. Pups start to take interest in the water at 4-5 weeks of age and learn to swim when they are between 3 to 6 months old.
Pups are weaned at around 4 months of age. The offspring of the breeding pair will help their parents raise the younger siblings.

Giant otter populations are in decline, with only 1,000 to 4,000 individuals estimated to be left in the wild. This decline is due to habitat loss and fragmentation, poaching, illegal hunting (for pelts), overfishing, and illegal mining, in addition to land and water pollution.

Not only does overfishing negatively impact marine biodiversity, but it also disrupts the food chain and puts local communities at risk of food insecurity. By eating sustainable seafood, you help ensure local communities have adequate access to seafood and jobs.

Zoo Atlanta has partnered with Save the Giants (STG) to support giant otter conservation as one of our Quarters for Conservation projects for the 2020-2021 program year. Save the Giants works to advance giant otter conservation by involving the local Guyanese community in field research to generate the information needed to make land management decisions. STG also provides training in best practices for sustainable, low impact eco-tourism to create employment opportunities.

The next time you are buying or eating seafood, download the Seafood Watch App to help you find sustainable options. You could also ask your server or the clerk at the seafood counter, “Do you sell sustainable seafood?”

Giant otters are the largest of the 13 otter species in terms of length.
Otters are very social animals. Typically, giant otters live in groups of two to 10 individuals, but groups of up to 20 have been recorded. Groups are composed of a monogamous breeding pair and their offspring from several generations. They engage in activities such as grooming, hunting, and resting.
They live in territories that are marked with scent from their anal glands. Burrows are dug by the family, first trampling vegetation, then piling up tree limbs to form a den.
Adults will aggressively defend their territory from intruders or predators. Giant otters are known as the “river wolf” in South America because they are one of the top predators in their aquatic ecosystem.
Otters are capable of complex communication, using up to nine different types of vocalizations. Their meanings are unknown but are believed to serve as warning signals when there is a potential predator.
Giant otters are land mammals who can swim, making them semi-aquatic animals.
Giant otters are diurnal animals. They are most active during the day and return to their dens at dusk.

Association of Zoos and Aquariums. (2009). Otter (Lutrinae) Care Manual [PDF file]. Retrieved April 17, 2020, from https://assets.speakcdn.com/assets/2332/otter_care_manual2.pdf
Dacres, K. (2001). Pteronura brasiliensis. Animal Diversity Web. Retrieved April 20, 2020, from http://animaldiversity.ummz.umich.edu/accounts/Pteronura_brasiliensis/
Groenendijk, J., Duplaix, N., Marmontel, M., Van Damme, P. & Schenck, C. (2015). Pteronura brasiliensis. The IUCN Red List of Threatened Species. Retrieved April 17, 2020, from https://dx.doi.org/10.2305/IUCN.UK.2015-2.RLTS.T18711A21938411.en.
Jetson, K. (2020). Impact of Overfishing on Human Lives. Marine Science Today. Retrieved April 29, 2020, from http://marinesciencetoday.com/2014/04/09/impact-of-overfishing-on-human-lives/
National Geographic. (2020). Giant Otter. Retrieved April 20, 2020, from https://www.nationalgeographic.com/animals/mammals/g/giant-otter/
San Diego Zoo Global. (2020). Otter. Retrieved April 28, 2020, from https://animals.sandiegozoo.org/animals/otter
Otter World. (2019). Giant Otter. Retrieved April 20, 2020, from http://www.otter-world.com/giant-otter/
Save the Giants. (n.d.). Giant Otters. Retrieved April 22, 2020, from https://savethegiants.org/giant-otters-2/
Zoo Atlanta Animal Care Team

Updated June 2020

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