Newly published research shows that: marmosets know how to call their mother from the moment they are in the womb

A study published in eLife found that marmosets begin to practice facial and mouth movements to call for help before they are born.

This finding may also hold true for humans. Ultrasound images in the third trimester of pregnancy show that the fetus in the womb makes movements that look like crying.

The first calls of humans and other primates are essential to survival. Calls allow marmosets to call family members for help. This interaction also lays the groundwork for more complex interactions later in the marmoset's life.

In the study, marmosets were ultrasounded 14 to 17 times.

Lead author Darshana Narayanan, who conducted the research at the Department of Psychology and the Princeton Neuroscience Institute, Princeton University, New Jersey (USA), said: 'We wanted to know the first voices of how babies develop'.

Narayanan and colleagues performed ultrasound scans two to three times per week in four pregnant marmosets. Each marmoset was ultrasounded a total of 14 - 17 times. This process begins when the fetus first appears on ultrasound and ends the day before they are born.

The team longitudinally tracked the head, face and mouth movements of developing marmosets. They then compared them to the meowing movements of newborn marmosets.

Using frame-by-frame analysis, the team found that, initially, the fetal head and mouth movements work together. However, mouth movements become distinct over time. In addition, the research results also show that the crying movement pattern before and after birth of the marmoset is different from the movement of licking or twisting.

'Our experiments show that marmosets begin to practice the movements necessary for important social interactions, before they can make sounds,' said researcher Narayanan.

According to the expert, further studying those movements of marmosets could help scientists learn more about the development of voices in other primates, including humans.

Study author Asif Ghazanfar, a professor at the Princeton Institute of Neuroscience, Princeton University concluded: 'The marmoset offers a unique opportunity to study vocal development in primates. Like humans, marmosets are very active. They learn to communicate through interaction with their parents'.