by Chimpanzees who live in Africa in a sanctuary have developed a “fashion trend” for the dangling grass sheets or sticks of their ear caves and their lagging behind, shows a new study.
In 2010 zagen onderzoekers die werkten bij Chimfunshi Wildlife Orphanage Trust Chimpanzee Sanctuary in Zambia hoe een vrouwelijke chimpansee objecten van haar oor begon te bengelen, en het gedrag werd al snel gekopieerd door andere leden van haar groep, studie -auteur Ed Van Leeuwen, een assistent -professor van gedragsbiologie aan de Utrecht University in de Netherland, verteld CNNN op woensdag.
There was no evidence that the chimpanzees used the grass or sticks to deal with pain or itching, and they were “very relaxed” when they did it, Van Leeuwen said.
The behavior is more a “fashion trend or social tradition,” he added.
Aimi, a female chimpanzee, who wears a stick in her ear- Jake Brooker/Chimfunshi Wildlife Orphanage Trust
Interestingly, chimpanzees in another group in the sanctuary started demonstrating the same behavior more than a decade later, with some also inserting objects in their rectums.
Because this group lived about nine miles from the first group, they could not have copied it from them, so that Van Leeuwen was asked whether the caregivers of the chimpanzees could have influenced them.
It appears that the staff in part of the reserve had developed the habit of cleaning their ears with matches or twigs, while those on the other side did not do that.
Van Leeuwen believes that the behavior was picked up by chimpanzees of caregivers in the first area before it was passed on to other members of their group.
The caregivers then also influenced the behavior in the second group, which they foreseen years later, before this group also developed the practice to put sticks and grass in their rectums.
“This is a trend that goes viral through social learning,” he added.
An adult male chimpanzee shows the same behavior in a wooded sanctuary for rescued large monkeys. – Jake Brooker/Chimfunshi Wildlife Orphanage Trust
Van Leeuwen also quoted the example of a group of chimpanzees in a zoo in the Netherlands where a woman started walking as if she was wearing a baby, although she wasn’t.
Soon all women had taken over this walking style, he said. Moreover, when two new women were brought into the group, the style that De Stijl took quickly was quickly integrated, while the one who refused to walk in the group style lasted longer to be accepted.
For Van Leeuwen, this behavior is about adjusting social relationships and smoothing out social relationships, just like in humans.
The grass behavior was usually observed on leisure time, when the chimpanzees come together to groom and play.
Living in the sanctuary, the chimpanzees do not have to worry about predators or competition with other groups, which means that they have more free time than their wild counterparts.
“They have a lot of time to just hang around,” said Van Leeuwens.
Nevertheless, his wild chimpanzees probably able to develop such behavior, he said, adding that it may not have been documented yet.
Subsequently, Van Leeuwens intends to study or can repeat new foraging techniques repeatedly to investigate whether they can develop cumulative culture in the same way as people.
Elodie Freymann, a postdoctoral branch of the primary models of the University of Oxford for Behavioral Social Lab, which was not involved in the study, said CNN that these types of observations are the key to promote our understanding of the origin and transmission patterns of cultural behavior in chimpanzees and other non-human animals.
“The finding of this study that perhaps interspecies have been copied between chimpanzees and their human carers is quite surprised,” she said.
“If chimpanzees can copy people, they could learn from and also copy other non-human species? It is an exciting moment in primatology,” Freymann added.
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