close up of a dolphins head underwater
Do dolphins lay eggs?

Do Dolphins Lay Eggs?

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  • Post category:Dolphins
  • Post last modified:11 January 2022
  • Reading time:7 mins read

Dolphins do not lay eggs. They are aquatic mammals, and just like most other mammals, dolphins give birth to their babies live.


On average, male dolphins reach their sexual maturity between 9 to 15 years of age, while female dolphins reach sexual maturity between 5 to 13 years of age.


Female dolphins do not have a set ovulation cycle. Female dolphins can ovulate spontaneously, meaning they can start to ovulate at any time. Female dolphins can also ovulate after the mother dolphin loses her baby.


Dolphins are not monogamous animals, so they do not stick to one mate. Dolphins have several breeding partners in a particular breeding season. In this case, dolphins are perhaps the only animal, except for humans and chimpanzees, that engages in sexual activity without having any goal of reproduction. 

Homosexual Behaviour

Dolphins also perform homosexual behaviours with other members of their group. 

The male-to-male sexual activity is considered a good sign of bonding.

Sexual encounters between females are also common among dolphin species. 

Sexual Aggression 

When two or more male dolphins want a female dolphin for mating purposes, in some instances, the male dolphins can stop the female from mating other potential partners except them. 

Also, If the female dolphin is not interested in sexual activities, she often tries to prevent the male dolphin from mounting her. In such a situation, the male dolphins can physically gang up and hurt the female dolphin to maintain control. 

Although in some groups observed, female dolphins of the same group will work cooperatively to help other female members escape such harassing situations from the males.

How long are dolphins pregnant? 

The gestation period of the dolphins lasts between 12 to 18 months. Generally, dolphin mothers carry a single baby dolphin and go through the normal labour process like any other mammal.

Recommended Read: Can you milk a dolphin?

Where do dolphins give birth?

The birthing process is completed in the water while the mother is swimming. Once the baby is out of the uterus, the mother dolphin quickly cuts off the umbilical cord and helps the calf come up to the water’s surface to take the first breath of air. 

The Big Birthing Difference Between Mammals and Dolphins

Mammals and dolphins have a big difference when they give birth. When a dolphin gives birth, the baby comes out tail first, not head first.

The Only Mammals Exceptions: Echidna and Platypus give birth to eggs

How often do dolphins give birth?

The dolphin mother does not engage in sexual activity when it nurses its baby. Dolphin babies keep breastfeeding until about 2 to 3 years of age. That means a female dolphin can be ready to give birth to another baby dolphin every 3 to 4 years. However, this timeframe can change depending on the dolphin species. In some cases, if the mother dolphin loses its baby early, it can become ready to give birth to another baby dolphin.

Do dolphins have a belly button?

Yes, dolphins have a belly button. The belly button marks indicate an umbilical cord connection between a mother dolphin and the baby. The babies stay connected with their mothers through the umbilical cord during pregnancy. The belly button of the dolphins is smooth and flat, which makes sure that the dolphins have a streamlined body, which helps them swim.

Baby Dolphin Dependency

Right after birth, dolphin calves become entirely dependent on their mothers. If their mother does not help the babies come up to the surface right after the birth, the baby dolphins can’t survive. 

As the baby dolphins do not have much body fat right after birth, if the mother dolphin does not help it to swim, it can drown just as quickly.

Massive Bond

That is why the babies form a strong bond with their mother right after birth. The bond between the dolphin mothers and babies is so strong that there is evidence that the mother dolphin will keep near the dead body of their babies for days to grieve.


After the calf is born, they always stay close to the mother. They remain in the low-pressure area that the mother creates while it swims. Staying close to the mother also helps the baby dolphin breastfeed whenever necessary. 

Slipstreaming also enables the baby dolphins to survive in the waters without the help of protective fat.

Nursing Time Length

The baby dolphin keeps on nursing until about 2 to 3 years. However, after they become a couple of months old, the baby dolphin starts to hunt small fishes under the close supervision of their mother. 

As the calf dolphin grows, they become less and less dependent on their mothers’ milk. 

Dolphin Milk

Dolphin milk is loaded with colostrum that helps to protect the baby dolphins from various kinds of infection. Whilst they are young, they need this milk to survive.

Recommended Read: Do dolphins have nipples?

Can The Dolphins Recognise Their Mother?

Baby dolphins can recognise their mothers during the nursing years. But they will eventually leave them when they are fully independent. They might not recognise their mothers if they meet them later in life.

That is why breeding between close relatives can also occur quite frequently. 

Although the ocean is a vast place itself reduces the chance of this kind of family reunion.

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Teresa Milne

Teresa is learning zoology and loves to share her knowledge through her articles. She has some pets that she adores two dogs, two cats, and one hamster. Teresa has also studied canine behaviour and canine nutrition.