It is with great pleasure that we welcome the newest addition to the Dolphin Island family. On the 17th December 2014, one of our Indo-Pacific bottlenose dolphins gave birth to a beautiful female calf. The mother dolphin is called Tian Tang (天堂), which means ‘heaven’ in Chinese.
Our veterinary staff and marine mammal team are closely monitoring the new arrival and her mother, and we have been very pleased with their progress over the last four months.
Here are 10 interesting facts about dolphin calves:
Tian Tang carried her calf for 12 months before giving birth, which is the normal pregnancy period for Indo-Pacific bottlenose dolphins. They typically carry single calves, and go through a similar pregnancy to other mammals. Ultrasound scans were conducted every two weeks throughout Tian Tang’s pregnancy to check on the development of the calf inside.
With dolphins, birth takes place in the water while the mother is swimming. The umbilical cord breaks as the calf descends through the birth canal, and once the calf is completely out of the canal the mother helps the calf to the surface to take its first breath.
Calves are typically born tail first, although head-first births (also known as breach births) have been observed. This is the opposite way round from human babies. The tail (fluke) is curled inside the mother’s uterus, and when the calf exits tail first the coolness of the water helps to harden the flukes, making it easier for the calf to swim to the surface.
As highly social animals, pregnant females are usually accompanied by small groups of males and other females. Some females have been seen taking on the role of ‘midwife’, assisting the mother during birth, and others act as ‘aunts’, taking care of the calf once it is born.
The newborn calf will swim near its mother to nurse. It will also learn to stay in mum’s ‘slip-stream’, tucked between her body and her dorsal fin. This provides protection for the calf, and pulls the calf along so that it can keep up with mum without too much effort.
Size at birth
When dolphin calves are born they are perfect miniature versions of their parents.
Our new arrival at Dolphin Island weighed around 7 to10 kilograms at birth, compared to a typical adult weight of 100 to 130 kilograms.
For several weeks our new calf had lightly-coloured, vertical creases in the skin on her sides.
These are ‘fetal folds’, which are caused by the way the calf is curled up inside the mother’s womb.
A newborn calf will start feeding from its mother anywhere between 2 and 6 hours after birth. The calf will continue to feed day and night for around 18 months. The mother’s milk is about 30 to 40% fat, and contains all the essential nutrients and vitamins necessary for growth and development, as well as antibodies to protect against disease.
Marine mammals have small feather-like projections on their tongue. They are able to roll their tongue like a straw which causes those projections to act like a zip, keeping the milk in and the salt water out.
Typically, a dolphin calf’s teeth begin to emerge at about 4 to 5 weeks. The calf will usually start eating solids at around 4 to 6 months, but this is very dependent on the individual. Even then the calf will continue to take milk until it is completely weaned onto solid food, much like a human baby.
Watching our new dolphin calf grow and develop over the last four months has been a remarkable experience. We will continue to document the calf’s developmental milestones, which will allow us to learn even more about this species of bottlenose dolphin. She is extremely interactive, and regularly engages socially with other members of our Dolphin Island family.
Update July 2015: Our dolphin calf has been named Isabelle.