Dolphins are marine mammals and share several characteristics found among almost all mammals, including breathing air, being warm-blooded, and carrying offspring in their womb.
Also, like other mammal species, dolphins typically give birth to a single offspring once every 1 – 6 years; however, on rare occasions, a dolphin may give birth to twins.
This type of reproduction is very different from other aquatic animals such as fish and amphibians as they are known to lay eggs that hatch (usually externally), meaning that the bond between child and mother is much less significant and unlike dolphins, fish and amphibians do not feed or nurture their child through an umbilical cord.
Additionally, these animals can lay thousands of eggs yearly rather than give birth to a single offspring every 1 to 6 years.
For dolphins, the average gestation period (from conception to birth) can vary significantly depending on the species, from 9 months up to 17 months!
As a species, dolphins are highly sexual and non-monogamous animals.
One dolphin can mate with many partners throughout its life.
During mating periods, when male dolphins compete with one another to find a mating partner, these marine mammals can become aggressive.
They may try to outperform one another through mating rituals or by fighting with each other.
In some cases, males may even become a horde of the female dolphin to prevent her from being impregnated by another male.
Researchers have also observed instances where whole groups of male dolphins may form a faction to fend off competing male dolphins from mating with a female or group of females.
In less competitive groups, males may attempt to court the female by bringing her gifts, singing, or displaying their youth and fitness through various acrobatic and water stunts.
What’s more interesting is that, unlike other marine mammals, dolphins don’t just mate during mating season.
Dolphins can mate any time of the year; some will mate just for pleasure.
As with their gestation period, the mating habits of dolphins can vary considerably between species and groups.
After giving birth, the female dolphin feeds her young by producing thick paste-like milk, which her child suckles from her nipple.
Dolphin milk usually has a high concentration of fat which allows the milk to travel through the water and into the baby’s mouth without breaking up in the water.
In some cases, the dolphin milk may have a thick paste-like consistency.
In addition to producing thick milk (which can travel short distances without breaking up), baby dolphins will create a very tight seal around the mother’s nipple to prevent it from contacting the salty ocean water.
Dolphin milk is full of nutrients and healthy fats, which are essential for ensuring that the baby dolphin gets the nutrients it needs to grow into a healthy adult.
Depending on the dolphin species and the baby dolphin feeding on the mother’s milk, suckling may continue anywhere between 6 months to 2 years or until the child can hunt for food on its own.
In some cases, a baby dolphin may continue to suckle from its mother even after the mother stops lactating until it can fully separate from its psychological bond and dependency on its mother.
Once the young dolphin reaches sexual maturity, it can begin looking for a mating partner and begin the process all over again.
Regarding characterizing dolphins as a family, the female dolphin is referred to as the cow, the male is called the bull, and the child is known as the calf.