North American River Otter

At the end of September, 2003, a new angel came into our life! We received a three year old North American river otter named Lulu. She was sought to become a new companion for Petey, who lost his (and my) dearly beloved Penny a few months before. (see the “Memorial Section.”) Lulu became extremely attached and affectionate with Petey almost from the first day. And, she came to trust me and treat me with the same affection after several weeks in which I was on “probation” in her eyes, not fully trusting me but giving me the benefit of the doubt. She now curls up in my lap, rubs her whiskers on my hand or shoulder, and even falls asleep on occasion in my lap. Petey is ecstatic, showing his pleasure and appreciation for saving him from the melancholy and suffering of losing his beloved mate in many very obvious ways. Prior to Lulu’s arrival, Petey seemed to lose interest in everything, moping about during his waking hours and sleeping much more. Now, he acts like he’s shed ten years. He hops around playing with Lulu and constantly reaches for me to pick him up and carry him about while he rubs his cheeks against mine in the most graphic communication of his appreciation and happiness one could wish to receive. Then, when he is placed back on the ground, he runs to Lulu, who deferentially rolls on her back for Petey to groom her neck and chest. It is a beautiful and extremely satisfying sight to behold!

Probably the most fun-loving animal that exists is the North American river otter. They are often called the “clowns of the animal kingdom.” They can find endless ways to play and to have fun, and they express their joy with playful squeals of pleasure and almost seem to giggle as they roll, chase, and interact with each other or anyone or anything that happens to be nearby. I have lived with two of these bundles of joy for thirteen years. Petey and Penny, pictured here, have given me more pleasure and made me smile more that anything else I know other than my two children. At this point, I must caution the reader not to go out and acquire a river otter! As far as I know, or as far as anyone else I have found knows, no one else has had the positive experience I’ve had living in close contact with these inquisitive, yet potentially aggressive beings. In fact I haven’t heard of anyone else that has successfully kept river otters past their maturity. If any readers know of anyone that has successfully kept river otters in a home environment past the age of three, I’d love to hear from them. River otters are related to the wolverine, known as the most aggressive predator in North America. They are quick to become agitated and angered by anything to which they take exception, and they can strike like a cobra. Once they begin striking at anything, they will continue and would undoubtedly fight to the death before they would back off. I have seen documentaries of a single river otter fighting off three coyotes and keeping them from her babies until all the otters were safely in their den.

While I have heard many horror stories of peoples’ attempts at having river otters once they become mature, my experience has been quite the contrary. Petey and Penny live in my house, and I spend well over an hour a day with them. It is perhaps the most pleasant part of every day. Petey loves for me to carry him around in my arms and lies on his back like a baby fondling my fingers. Penny loves to roll over on her back and have me tickle her tummy while she playfully tries to nip at my fingers. They play endlessly on their slides and take stuffed animals to bed with them. They have a collection of about fifty stuffed animals that Penny carefully places in a corner of their room, selecting three or four of them to take to bed each night.

I spend countless hours lying outside with them, the three of us playing like children. They will rummage through my pockets and inside my shirt or jacket, then rub their whiskers against my cheek lovingly, chatter affectionately, then perhaps Petey will curl up in my lap on his back holding my hand in his paw before Penny gets jealous and jerks him out of my lap. The two of them then roll around on the ground nipping and play-fighting with each other. I will often join in, rubbing their bellies and tickling Penny while they play. Although they may be constantly nipping each other during this time, I will never feel a tooth.

Petey and Penny spend all their time awake trying to find interesting games to play and ways to get where they aren’t supposed to go. Their apartment has a bathroom. One day Petey decided to push a heavy metal chair over to the door of the bathroom. He then climbed the chair and worked with the doorknob until he learned how to open it. They then went into the bathroom and rearranged everything, putting all loose objects in the toilet. I put a hook and eye high up on the door with a sliding “child proof” bar that works with a spring. Petey pushed the chair back over to the door, climbed up on the back of the chair to get higher, then opened the hook and eye, the doorknob, and proceeded to trash the bath room again. When I went into the room for my nightly check before retiring, I noticed immediately, before even rounding a corner to the room, that Petey had his chest stuck out proudly and had a mischievous grin. I knew right away he had done something he was proud of, before even seeing the bathroom door.

I wish to acknowledge my appreciation to my dear friend, Chris Bellows, formerly Assistant Curator and Director of Animal Interaction at SeaWorld, San Antonio, Texas. Chris’ advice and consultation on river otters was extremely helpful in the early years with Petey and Penny. Even now, we often exchange ideas and experiences and come up with suggestions to improve the lives of animals under each other’s care. I wish that more people in the animal-related field would exchange ideas and experiences for the benefit of all animals.

I could write stories about Petey and Penny for pages and pages, but it would override the remainder of this website. If readers want to know more, let me know and I will perhaps write additional stories from time to time.

Characteristics of river otters:

Lontra canadesis

The North American river otter is part of the family called mustelids, which also includes weasels, minks, ferrets, badgers, skunks, and wolverines.

Historically otters were found over much of the North American continent. They occupied one of the largest geographic areas of any North American mammal. They were found in all major waterways of the U.S. and Canada until at least the 18th century.

Otters generally become secretive, if not actually nocturnal, where human disturbance makes daylight activity stressful. They seem to be more diurnal in the winter than during other seasons, and it has been thought this way because humans are relatively less active in the otters habitats during the winter months.

Their dens vary according to the habitat availability. Rather than excavate their own dens, otters often use natural formations, man-made structures, and dens built by other animals. Old beaver dams are common, as well as muskrat lodges, log jams, niches in river banks, hollow tree bases, and piles of rock, logs, or brush. They line their dens with moss, grass, and leaves. Their dens are commonly underground and near water.

Otters are more social than most other mustelids. Groups of as many as 30 otters have been seen playing or eating without any friction. However, males are generally solitary. Females live within group ranges, but with a core area where they spend more than half their time exclusively. Otters tend to avoid conflict with one another through mutual avoidance. There is a social hierarchy in an area. A subordinate animal will go to great lengths to avoid the dominant, which appears to ignore the presence of its inferior. Scent marking with feces, urine, and anal sac secretions helps accomplish mutual avoidance. This technique is known as sprainting. Otters become most territorial during breeding season and will fight if necessary. After giving birth, females temporarily become dominant to males. While the family unit generally consists of the mother and her cubs, but sometimes the father is also accepted into the family.

Otters are carnivores, and they eat fish primarily. However, they have also been known to eat blueberries and aquatic plants such and roots and pondweeds. While some fishermen suspect them of depleting game fish stocks, they actually prefer slower-moving “trash fish,” as catfish. They also eat freshwater mussels, frogs, and turtles. They also like crustaceans. They tend to stay close to shore when fishing so they can quickly take their food on land to be consumed.

They have a chestnut brown coat on their back, while their chin, throat, and belly region are somewhat lighter beige. They have two layers of fur: a dense inner layer of fine, soft hair fibers, and a longer, coarse outer layer of guard hairs, Several of the inner fibers combine and connect at each individual guard hair. They undergo a molt in spring and fall. Their tail is 1/3 their total length. It is used as a rudder when swimming, and for balance when standing on its hind legs. They have broad snouts, small ears, short legs with fully webbed feet, and a thick but tapering tail.

They can swim up to 8 mph. They swim by tucking their front paws in close to their flanks and propelling themselves with a powerful flexing of their hind legs. The hind legs can be kicked out for additional power, when necessary. They can stay underwater for up to five minutes. They do this by reducing their heart rate from 150 to 10 beats per minute, slowing circulation to their limbs and allowing the blood to retain more oxygen.

They maneuver through the winter snow by “tobogganing” on their bellies or backs along stream or river banks. They also have specially adapted lenses in their eyes to accommodate underwater distortions. They have a clear, third eyelid called a nictitating membrane that covers their eyes when swimming underwater. This gives protection to the eye but allows the otter to see clearly.

They have a metabolism about 20% above the standard for their body mass. This keeps them at a healthy temperature. The oils in their fur make it virtually waterproof. As they dive beneath the surface of the water, a trail of bubbles follow as air escapes from its insulating form between the fur layers. This also reduces buoyancy.

Otters breed from December through May. They reach sexual maturity at two. Males normally aren’t successful breeders until they reach four. Mating occurs most frequently in the water. They may mate several times in successive days. A male on the tract of a female in heat or in the act of mating may become very aggressive if disturbed or challenged. Some go berserk and will charge anyone near, whether man or animal. The gestation period lasts about a year. Females usually use the same nest for birthing only one time. They generally have two to four cubs. The cubs begin eating solid food at around two months of age. The cubs are born in the spring, blind and toothless and about the size of a chipmunk. They are completely helpless until they are five to six weeks old. They are usually weaned at three months. At three months, they develop their waterproof coat and prepare for their first swim. Sometimes, the mother must drag the babies by the loose skin of the neck in order to get it into the water. The mother will catch a fish, call to the cubs, and let the fish loose upon their arrival. The cubs are usually catching their own fish at four months. They are basically self-sufficient at five to six months. At this point, the mother may let the cubs interact with other animals, including the father, who is generally ostracized from the family until that time. The family may then stay together through the fall, but the cubs will leave by spring. The cubs will leave at about eight months.

Otters have various means of communication. Their expressions tell a lot about their mood: An intensely motionless stance communicates alertness, a motionless pose while lying on its back shows submission or desire for play, muzzle-touching and mutual grooming are socializing and affection, pulling the ears back and showing an open mouth is a “threat-face.”

They have various vocalizations: snarling growls indicates anger or being very disturbed, screams or screeches mean frightened or uneasy, low growls are a threat, bird-like chirps are calls or contact between family members, grunts such as un-huh, un-huh are signs of being startled, uneasy, or uncomfortable, low murmuring or chuckles are friendly or contact calls.

Otters have few natural predators. Those known to occasionally prey upon otters are bobcats, coyotes, foxes, and alligators. Few diseases seem to affect otters, due to their aquatic behavior. This all changed with the beginning of the fur trade in 1534, when French explorer Jacques Cartier traveled through the mid-west. River otters had nearly disappeared by the end of the nineteenth century. Otters are considered “keystone species” by researchers. This means that, due to their diets, sizes, and physical tolerances for environmental variability, they serve as an early detecting system for problems in the environment.

Otters live an average of 15-20 years, with 23 years being the documented record in captivity. Rabies has never been reported in N.A. river otters. In general, the more variety in a captive otter’s diet, the less chance of nutritional deficiency.

Adult river otters are three to four feet long, including a one to one-and-a-half foot tail, and they generally weigh 15 to 25 pounds.

It has been said that, if playfulness is a measure of intelligence, river otters must be among the smartest of all wild animals. They’ll chase after a pebble, a shell, or each other for hours. Their favorite activity is body-sledding down a slippery slope and landing with a belly flop in the water. They’ve been known to swim up to a beaver and mischievously tweak the beaver’s flat tail.

They are devoted parents. Unusual among mammals in that the father often rejoins the female when the young are weaned and old enough to leave the den. He helps in raising the babies. Young otters don’t take willingly to water at first, and the parents have to coax them. They can dive up to 60 feet deep and stay under for five minutes.

Otters sleep approximately half their lives. They travel up to 15 miles an hour on land, and about 8 miles an hour in water. They have well-developed senses of smell and hearing. They also use their whiskers to detect prey when hunting and obstructions when swimming.

About Louis Dorfman

He has worked with many species of wild animals for over 60 years, both in protected and unprotected contact. At IEAS he rehabilitates exotic cats that have been abandoned, abused, and/or confiscated and in most cases changes the reactions of the cats to humans from one of fear and hate to an attitude that the humans are there for security and support for the resident cats. Over the years, he has worked with over 150 exotic cats at the sanctuary alone.