I was lucky enough to be in Bali recently on a dolphin-watching trip. I wanted to know how dolphins breastfeed their young underwater, so I asked one of the guides. His answer left me with some questions, so I looked into this further when I got back to shore.
Dolphins have inverted nipples inside mammary slits. When the calf is ready to feed, they dive underneath the mother and nudge the mammary slits. The nipple is released, and the mother provides milk to the calf that rolls its tongue into a U-shaped tube.
Dolphins are mammals and milk is essential for the growth and well-being of them as they grow. The water provides challenges that are different from land mammals, but dolphins use several adaptations to feed underwater.
How Do Dolphins Breastfeed Underwater?
All mammals have developed different, unique mechanisms that enable them to survive in their environments. Dolphins are surrounded by water, and breastfeeding in this environment is not as easy as it would be for a land mammal.
Dolphins have two mammary slits on their underside, with an inverted nipple inside. The nipples do not protrude the same as terrestrial mammals, and young dolphins can not feed at any time as land mammals can.
When the calf is ready to feed, they dive underneath the mother and nudge the mammary slits. This signals to the mother that the calf is ready to feed. This also stimulates the mammary slit to release the nipples.
Whereas the young of land mammals will regulate the amount of milk they take from their mother, marine mammals are different.
The young calf wraps its mouth around the teat, rolling its tongue into a U-shaped tube. The rolled tongue is pressed onto the upper palate and placed around the nipple.
Dolphin calves do not control how much milk they take, leaving the mother to decide. The female’s mammary glands have muscles that contract and then shoot milk straight into the mouth.
This ensures that the milk is channeled directly into the mouth and that none is lost in the water.
The mother will lay on her side during the first few weeks after birth to help the young find the mammary glands. After the first few weeks, the calf will swim on its side to drink the milk, and the mother slows down their swimming.
One of the main reasons dolphins can successfully breastfeed underwater is due to the milk’s consistency. Whale milk has an unusually high fat content.
High-fat concentration in the milk is necessary because the adult female whale can eject liquid into the calf’s mouth without dissolving into the water around their lips.
Do Dolphins Produce Milk?
Dolphins are marine mammals and possess the typical characteristics of all mammals. This means they have mammary glands and produce milk to feed and grow their young.
With all species of dolphins, calves require plenty of milk for them to grow and stay healthy. A newborn consumes milk every 20 minutes, 24 hours a day. As they get older, this happens less frequently.
Dolphins have been seen to nurse their young for up to four and a half years, although this normally stops after a minimum of two years.
Do Dolphins Have Nipples?
Whales do have nipples, but they are not on the outside of the body as in humans. Nipples can also be found on most male whales as well as females. As they spend their entire life in water, any protrusions such as nipples could get damaged outside. Whales have inverted nipples, different from terrestrial mammals that have protruding nipples.
Dolphin nipples are enclosed within skin folds, referred to as mammary slits. Whenever a calf wants milk, it nudges the mammary slits, stimulating the mother to expose the nipples.
What Is The Consistency Of Whale Milk?
Dolphin milk has a very thick consistency. The thickness is because of the high-fat concentration which reaches approximately 3.8 to 6.4 ounces per liter. Full-fat cow milk typically contains around 3.5% fat. This means that there are approximately 1.23 to 2.08 ounces of fat in one liter of full-fat cow milk.
Dolphin milk is white with a yellowish tinge and a creamy consistency. The taste is oily and lacks sweetness, and has a fishy odor and taste. (Yes, I have tried it!!)
How Long Do Dolphins Breastfeed?
Baby dolphins need milk to survive and grow. Once they are large enough to survive without the milk, they change to a diet consisting mainly of fish.
Most dolphins will stay with their mothers for at least three years. Calves can grow extremely fast in their first year, reaching seven times as large as when firstborn due to the milk’s high-fat content.
Dolphins only give birth to their next calf when the last calf has been fully weaned. Due to this, dolphins will only have another calf after at least three years.
Dolphins do not reproduce very often, which allows plenty of time for the calves to grow fully and increase their survival chances. The mother will lactate and produce milk until the calf has been weaned.
What is the Importance of Milk to the Young Dolphins?
As with land mammals, milk is vital to a young dolphin’s existence. Baby dolphins need milk for healthy nourishment and to grow.
Dolphin calves survive on milk until they are ready to wean. Without milk, dolphins have low survival rates, and will starve to death. A newborn dolphin consumes large amounts of milk daily and is their sole source of food at this time.
The milk is nutrient-rich for the baby dolphin to grow and thrive. The liquid is packed with healthy fats that provide energy to the calf. Other nutrients needed to boost the immune system, support bone development, and ensure the brain functions properly are all included.
Breastfeeding creates a bond that is unbreakable between the mother and her calf. This bond is essential for the development of the young dolphin.
Research has proved that the relationship between marine mammals and their parents is crucial for survival. Marine mammals living in captivity have shorter lifespans than their counterparts in the wild. In captivity, dolphins cannot nurture naturally as they would in the wild.
Dolphin milk contains a high concentration of fatty acids. The fat in the milk helps develop blubber, a thick layer of fat under the skin of dolphins.
Blubber develops as the dolphin grows. Since dolphins spend all their time underwater, they must prevent heat loss and keep their body temperatures constant.
Blubber acts as an insulating layer against the coldness of the water. The high-fat content from the milk allows the blubber to develop.
References And Further Reading
Bryan Harding is a member of the American Society of Mammalogists and a member of the American Birding Association. Bryan is especially fond of mammals and has studied and worked with them around the world. Bryan serves as owner, writer, and publisher of North American Nature.