Awesome Animal - Giant River Otter

I don't like giving spoilers about my upcoming novel, INFINITY, but I simply cannot resist telling you this. Our bridger heroes and their clients encounter river otters. But these otters are not like the otters you've seen here in our own world. The otters in INFINITY are... well, there I go again, trying to tell you too much!

I'll just say that the otters in INFINITY are why I chose today's Awesome Animal, the giant river otter. River otters have a reputation for being cute and playful (although those in INFINITY certainly are not), but are they really? Let's find out more about these creatures.

So, what the heck is a Giant River Otter?

Otters are carnivorous mammals in the family, Mustelidae (this is the family that includes all those long, skinny critters like ferrets, weasels, mink, martens, wolverines, and more). There are 13 living species of otters throughout the world, including the river otter, which is fairly common here in Missouri. The giant river otter, on the other hand, lives in South America, particularly in the Amazon River Basin. This is the largest living otter species, and it grows to 5.6 feet (1.7 m) and weighs up to 71 pounds (32 kg). In comparison, the North American river otter that lives here in Missouri weighs only 10 to 30 pounds.

Amazing facts about Giant River Otters

The giant river otter is one of three otter species in South America. But strangely, it is not as closely related to the other South American species as it is to the smooth-coated otter that lives in Asia.

Giant otters are the longest of all the mammals in the mustelid family, although the sea otter might be a bit heavier. Above, I gave the maximum length of 5.6 feet. But it is likely that they grow longer than this, as early reports on sightings and the skins of giant otters indicated that there used to be huge males that were as long as 7.9 feet (2.4 m). Try to imagine swimming next to an 8-foot otter! Unfortunately, these large individuals are not seen today due to overhunting.

Giant otters are classified as endangered. Hunting them is now illegal, but their numbers are still being reduced by deforestation, water pollution due to runoff from farms and oil drilling sites, and poaching (it is hard to catch poachers in the area where giant otters live).

Giant otter babies (called cubs) are born completely covered in fur. In fact, they are one of the few species of carnivores with noses that are completely covered in fur. The cubs are usually born in underground dens near the banks of slow-moving rivers. They are helpless at birth, and they don't learn to swim until they are two months old.

Below is a giant otter pup born in a zoo in Singapore.

Giant river otters, like other otter species, live in family groups, and they are very social. In fact, their social behaviors include hunting, grooming, resting, and communicating. For communicating, they have nine different vocalizations. Most of these are probably for locating each other or for warning each other about predators.

Here's an explanation for why otters play together so often. First, it's important to understand that otter social behavior and cooperation are crucial to their survival (the obvious example is cooperative hunting). When otters play together, they are strengthening their social bonds, thus insuring effective cooperative behaviors.

Check out this video of a family of giant otters working together to kill a large caiman.

Although giant otters typically eat fish, they often kill and eat larger prey. And they are always hungry. They eat six to nine pounds of food per day! In addition to fish, they also eat crustaceans, snakes, and just about any other river creatures they can catch and kill.

All otters are excellent swimmers, including the giant river otter. They propel themselves with their tail and with their large, webbed feet. They also flex their long bodies as they swim. Their thick, water-repellant fur keeps their skin dry and warm. And, as if that weren't enough, they can close their nostrils and ears to keep the water out. You've probably noticed that otters have very small ears. This helps their speed also.

Giant otter family groups usually have four to eight individuals, but families of up to twenty have been observed. A family group is usually the two parents (which are monogamous) and the last one or two litters of pups.

Each family group has a large home territory, averaging almost five square miles (12 square km). They patrol their territory regularly, marking the borders with their anal glands. If other otters trespass, they will defend their territory viciously.

Within a family group, the subadults have the task of caring for the newest pups. So they are kind of like sibling babysitters.

Giant otters are mostly dark brown, but each individual has a white marking from the chin to the chest. These markings are different on each otter, and they use these to identify each other. It's interesting that these markings are in this location (on the chin). Otters have cool habit of "snorkeling," which is when they thrust themselves upward out of the water with their heads high. This allows them to see farther. But it also exposes their distinct markings to the other otters they are facing.

Check out the markings on these two giant otters:

So, the Giant River Otter deserves a place in the S.G.A.H.O.F.
(Squad Goal Animal Hall of Fame).

FUN FACT: Okay, this one's really a stretch. I was reading an article about slang terms that millennials use. The phrase squad goal is used to describe the type of behavior that friend groups aspire to. Here's an example: When you see Harry Potter and his friends gear up to defeat the Dark Lord, you could say "Squad goal." This means you admire the way the group is working together, and you are suggesting that your own group (squad) should strive to work together in such a way. And since giant river otters are so good at cooperative efforts, I thought this phrase was perfect. So, squad goal is another way to say awesome!

Photo Credits:
Giant Otter Underwater - Wildlife Reserves Singapore
Giant Otter Pup - Zooborns
Otter eating caiman - Reddit
Giant Otters Snorkeling - World Land Trust