Confectionery Company Will Pay You $ 30 An Hour To Sample Trial Sweets, Plus This Week’s Weirdest News | New
Marmosets can understand conversations between other monkeys and judge whether they want to interact with them, new research shows.
Scientists at the University of Zurich played marmosets audio recordings of voice interactions between their peers and recorded their behavior and body temperature to gauge their reaction, said the American Association for the Advancement of Science in a press release issued on Wednesday.
Animals reacted differently depending on their gender and social status – those with offspring, called breeders, or those without offspring, called helpers.
The researchers showed 21 adult marmosets recordings of an adult of the opposite sex interacting with a begging infant, making food offers or aggressive calls.
Scientists also played the baby beggar, and the adult’s food offering and aggressive reminders individually as a control.
The noses of marmosets and other monkeys change temperature depending on their emotional state, with stress causing the temperature to drop as blood rushes to central organs, Rahel Brügger, a doctoral student in anthropology at the University of Zurich.
The researchers measured the change in temperature when the marmosets listened to both individual calls and the two interacting marmosets.
Scientists found that the temperature change in the nose was greater when the marmosets listened to an interaction than the sum of the temperature changes when they heard the individual calls, which led to the conclusion that the marmosets interpret the interactions as conversations.
“These marmosets aren’t just passive observers of interactions with third parties, they actually interpret and understand what the third parties are doing,” Brügger said.
In general, helper marmosets experienced greater temperature changes than their breeding peers.
The noses of female helper marmosets have cooled after listening to the males interact with the infants, as this indicates a nearby group with young monkeys and the presence of competing females. “In the wild, this would be difficult for these marmosets,” Brügger said.
The nasal temperature of male assistants rose after listening to aggressive interactions or a female call per se, as this could indicate a potential mating partner, Brügger explained.
“Different stimuli for different people can mean different things,” Judith Burkart, university researcher and doctoral director at Brügger, told CNN.
The team then tested whether the marmosets would seek to interact with the sharer or aggressive monkey by simultaneously opening two compartment doors.
One door would allow them to return to the original enclosure, while the other opened to an additional compartment from which a hidden speaker played either food sharing or aggressive interaction.
Marmosets showed a preference for cooperative adults because they were more likely to walk through the door where the food-sharing call was played, Brügger explained.
“They are even more curious about the potential mating partner if they assume (based on the reading) that the potential mate is a cooperative rather than a competitive mate,” she said.
The research published Wednesday in the journal Science Advances.