Sea Otters, Mating, Reproduction, Babies, and More

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Last Updated on July 5, 2022 by Tommy

Sea otters (Enhydra lutris) commonly live in shallow coastal waters. The Pacific Ocean coasts of North America and Asia are the home to this weasel-like water mammal. 

Despite their cute appearance, sea otters are wild animals and can be dangerous. They have large teeth and a powerful bite, which means that they should not be messed with. 

Female sea otters go to great lengths to protect themselves and their young from possible dangers. They are very protective and attached to their babies and will do everything for them.

In this article, we’ll explore how these animals find their mate, reproduce, and care for their cute babies!

What Time Of The Year Do Sea Otters Mate?

Sea Otters can mate only once a year during their oestrus cycle. This heat period of a female otter can happen any time of the year, but only once per year. It usually lasts for several days. 

Even though mating can happen anytime, there are reproduction peaks in the Aleutian Islands in May and June, and in California in January and March. In addition, the mating season of North American zoo otters, or sea otters in captivity, starts during winter and spring. 

How Do Sea Otters Find A Mate?

The male sea otter courts the female sea otter to begin the seduction process. Male sea otters engage in playful and sometimes aggressive behavior when mating.

The male otter will only mainly approach females that occupy his own territory. In cases where the male doesn’t have an established territory, he will search all around for females in heat.

Males often swim faster with their faces down in the water when courting. After encountering a female sea otter, the male will try to embrace or sniff her body. 

A period of rolling around and playing ensues if the female is interested. The male is either pushed or forced away if he is rejected. During mating, the pair will separate themselves from their groups for several days.

Do Sea Otters Mate For Life?

No. Sea otters are polygamous animals, which means that they mate with multiple partners over the course of their lives. After mating with one female, the male will move on to mate with another, leaving the young in the care of the female sea otter.

After mating, the sea otters will go back to their respective rafts. Sea otters hang out in groups called rafts and are commonly separated into groups of males and females with pups.

When do Sea Otters Become Sexually Mature?

88% of female sea otters reach sexual maturity by the time they are four years old. On the other hand, the male otters will follow at the age of 5 and 6 years old.

Females often give birth to their first pups between the age of 3 and 4. The reproductive rate of female otters reaches its maximum at the age of five and remains relatively constant until fifteen. 

How Do Sea Otters Mate?

During mating (copulation), an intense game of chase, swim, dive, twist and lunge happens. The male holds the female by her neck, occasionally pushing her head underwater while attempting to overpower her during violent and prolonged copulation.

The male uses his jaws to grip the female’s upper jaw or nose to keep a hold of the female. The male otter wraps his forelegs, or arms, around the female’s torso while mating. 

Mating lasts from 10 to 30 minutes in the water. The pair will spin in the water until they are done mating. Females that engage with them bear visible scars due to it, and their noses sometimes turn bleeding red after mating. 

Can Sea Otter Mating Be Violent?

Mating aggression is common in male sea otters. Forcing their teeth into the female’s nostrils, males can cause extensive wounds and gouges, tearing away portions of her flesh. 

It’s very possible that this aggression will become life-threatening for the female sea otter, whether from the physical trauma she has suffered or through drowning. The otter population’s overall death rate is growing, significantly affecting females.

A greater number of mature male sea otters are unable to mate, which leads to more violent sexual encounters when they do occur. They’re not only cruel to female sea otters and their young, but they’re also dangerous to other animals.              

Male otters who have been denied the opportunity to mate take their anger out on helpless newborn harbor seals. Forcibly mating with juvenile harbor seals has been observed in 19 cases, which resulted in the deaths of 15 of the 19 seals.

How Long Is A Sea Otter Pregnant For?

The gestation period of the mother sea otter varies and might range from four to twelve months (including delayed implantation and pregnancy). This means that the mother can birth her baby anywhere from 4 to 12 months from when she was originally ovulating.

The egg cell undergoes several alterations after fertilization. The blastocyst stage occurs when the cell divides several times and travels to the fallopian tubes from the ovary to the uterus. 

For two to three months, the development of sea otters is put on hold (delayed implantation). The delayed implantation will ensure that the pup has a better chance of surviving because the pup will be born with optimal environmental conditions. It gives the female sea otter the time to recuperate from her previous pregnancy.

Sea otters are among the few mammals that may not implant their embryos immediately after fertilization. But rather, they stay in a suspended development state, allowing birth to occur under ideal circumstances.

What Time Of Year Do Sea Otters Give Birth?

Sea otters can give birth at any time, but most of them give birth during spring. North American sea otters often give birth during the winter and spring seasons, usually a year after breeding. In the Aleutian Islands, births peak from May to June, and in California, from January to March.

How Often Do Sea Otters Reproduce?

Sea otters can give birth once every year. There are instances where the female otters experience a longer birth interval and can only give birth once every 2 years.

How Do Sea Otters Give Birth?

Sea otters give birth on land or in the water, but they mostly give birth in water. This is one of their unique features as other otter species give birth on land. 

While giving birth in water, the female otter will continue to spin as she pushes her baby out. As soon as the baby’s tail comes out, she will gently pull it. After a successful birth, she will place the pup on her belly to be groomed.

There are instances where sea otters give birth on land or rocks. Similar to giving birth in water, they’ll gently push the baby until they see its tail. Using their forepaws, they carefully pull and help the baby out. To keep the pups buoyant, she takes great care in grooming them thoroughly.

Mother sea otter giving birth in water:

Mother sea otter giving birth in rock: 

How Many Pups Do Sea Otter Mothers Have At A Time?

Sea otters give birth to a single pup in each litter, weighing between 3 and 5 pounds. There is only a 2% chance that sea otters will give birth to twins. 

In the rare event of multiple births (2 to 5 pups), only one of the pups will be kept by the mother to be raised. The other pups are going to be abandoned.

What’s A Baby Sea Otter Called?

Baby sea otters are called pups or kittens. They hang around with their mother until they are 1 year old or when the mother has another litter. 

Many pups are born in the spring and early summer. Female otters bring their young pups ashore to rest for a long time referred to as hauling. In undisturbed environments with abundant food sources, female reproductive rates and pup survival rates tend to be greater.

How Do Sea Otter Mothers Take Care Of Their Babies?

Sea otters are some of the most loving mothers in the animal kingdom. The mothers not only have to suffer through the harsh mating rituals, but after the baby is born, they dedicate almost all of their time focusing on their young.

The mother sea otter spends the first three months of her baby’s life caring for it while carrying it on her belly. Using her teeth, she handles the pup by the loose skin on its neck and swims to safety if she feels threatened.

When she can leave the pup alone on the surface, she’ll go search for food. She’ll do this by diving and gathering food throughout the weaning period. She needs to gather enough for both her and her pup.

The pup is completely dependent on its mother’s care and attention for the first six months. After this moment, the pup starts to dive down with its mother. The pup will learn carefully to forage for food under the supervision of its mother.

Sea Otter Mothers Wrap Their Babies In Kelp While Foraging

Mother sea otters frequently use kelp strands to entangle and attach their pup when diving for food.

The buoyancy of newborn pups prevents them from diving for food right away, so they use the kelp as an anchor, almost like a seatbelt, to keep the babies safe and prevent them from drifting until the mother returns. At around two months old, pups begin joining their mother in diving and foraging. 

Why Do Sea Otters Hold Up Their Babies?

The mother will carry her pup on her belly to prevent it from floating away when it is still a little pup. Mothers will constantly blow air into their pup’s fur, making it buoyant and acting as a life jacket. Because they cannot swim, sea otter pups rest on their mother’s chest as she swims on her back.

Do Baby Sea Otters Know How To Swim?

Baby sea otters can’t swim until they are about four weeks old. Mother otters will start teaching them to swim after they start eating solid foods. 

They can only start diving after 6 weeks as newborn pups have special buoyant fur that prevents them from sinking. They can’t dive; therefore, they float like corks on the water’s surface, fully dependent on their mother.

Sea Otter Moms Spend A Lot Of Time Grooming Their Babies

Sea otters groom their fur for their survival, but since the cubs can’t groom themselves, mother sea otters can constantly be seen cleaning and grooming their pups. She rests her newborn baby on her tummy and carefully grooms it from head to tail. This is both a bonding experience and a matter of survival.

Sea otters actually have the densest fur in the animal world. As they lay on their backs, their thick fur acts as an insulator, keeping them warm and allowing them to stay afloat. 

Grooming helps them survive because wet or dirty hair would clump together and release the air trapped between the hairs. Dirty fur makes it harder for sea otters to float and survive in water, which is why sea otters have to spend so much time grooming themselves and their babies. 

This is partly why sea otters can stay afloat in coastal waters: Thanks to their clean and well-groomed coats.

How Do Sea Otter Moms Keep Their Babies From Screaming?

Mothers frequently lick and groom their pups to prevent their babies from crying or making noise. Sea otters’ mother-baby attachment and bonding are strengthened by grooming and bonding. 

Baby sea otters usually cry when asking for food, excitement, or attention. When the mother licks her baby’s head, it reduces stress and provides comfort.

In some instances, sea otter mothers have been observed lightly putting their little paws over their babies’ screaming mouths in order to silence them. This might look like the wrong way to raise your children, but for sea otters, it’s essential that babies learn to stay silent when danger is near.

It also looks quite cute to see a mother sea otter use alternative methods for getting a bit of calm after a long day of mothering!

What Do Baby Sea Otters Eat?

While they are still blind, baby otters rely on their mother’s milk as their only source of nutrition. Pups will begin weaning at the age of two months. The pups will slowly start weaning when they are 2 months old and continue until they reach 11 months.

During the weaning period, the pup will eat what the mother provides during the hunt. This consists of a solid diet such as aquatic invertebrates, sea urchins, various kinds of seafood, and some fish. When the weaning period is over, the young sea otter will begin to hunt on its own.                                                      

How Long Do Baby Sea Otters Stay With Their Mother?

The baby sea otters will stay with their mother for a minimum of 6 months to a year. The mother must constantly eat to nurture her pup for four to twelve months and educate them to survive and grow. This will continue until the baby sea otter develops its survival skills.

How Can You Tell The Difference Between A Male And A Female Sea Otter?

A male sea otter’s regular weight ranges from 50 to 100 pounds (23 to 45 kilograms), whereas a female’s average weight is 45 pounds (20 kilograms). 

Otter males are known as boars, females as sows, and their babies as pups or kittens. You can distinguish female sea otters when they are resting or grooming. 

Since females nurse their young, the presence of their udder (mammary gland) is visible when they float in the water. You’ll notice that they have four permanently extended teats due to prolonged lactation. However, adult females who haven’t given birth are hard to identify because they have not lactated yet.

On the other hand, a male otter can be distinguished through the presence of its testes and scrotum.

What Should I Do If I Find A Baby Sea Otter?

Call the wildlife rehabilitator in your area if you find an abandoned baby sea otter. Female sea otters who are unhealthy and can’t care for their puppies are more inclined to leave them after birth to improve their chances of having a successful litter. 

To preserve and not threaten future reproductive efforts, the mother can leave their child earlier to be independent. However, this method puts the young in increased danger as they leave their mother’s care earlier than intended.

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