Mother Dolphins Perform Signature Whistles, Sing To Their Babies In Their Wombs

A study reveals that dolphins perform a signature whistle or 'sing' to their unborn calves just like some parents, who talk or play music to their unborn children. The mother dolphins do this while the unborn calves are still in their wombs running up to the birth and up to two weeks after.

The study was led by researchers from the University of Southern Mississippi. Audra Ames, a doctoral student at the University of Southern Mississippi said that it's been theorized that this is part of an imprinting process. She further said that in the earlier studies, the mother dolphins begin shrilling their signature whistle more in the days before the delivery, and then in the calf's first two weeks of life. Many theories state that probably the mother dolphins are trying to get their babies to develop their own signature sound, according to Live Science.

Signature whistles are a type of vocalization send out by bottlenose dolphins. They are usually used in communication within the species. They also have specialized functions, properties and for locational purposes. The signature whistles are significant in group cohesion and social interaction. Each dolphin has a unique signature whistle.

In the 2012 and 2014 studies, Ames and her colleagues examined the signature whistle rates of the dolphins through a baby dolphin named Mira, which was born to a 9-year-old mother at Six Flags Discovery Kingdom in Vallejo, California. The team took 80 hours of recordings from the two months before and the two months after the dolphin's birth. These involve the mom and the calf together with the five dolphins. Ames explained that it is important to capture the noises of the mother's peers to comprehend whether the communication is exclusive to the mother-baby pair.

The researchers discovered that the mother dolphin began augmenting her signature whistle two weeks before the birth. This is also observed in human pregnancies. Ames stated that they actually do see that human babies develop a preference for their mother's voice in the last trimester. She further stated that they don't know if that's something that's going on here, but it could be something similar.