The bottlenose dolphins of Shark Bay on the west coast of Australia sometimes hunt fish using shells.
Dolphins seem to be learning this technique not from their parents, but from their peers of the same generation, according to a new study. The transmission of technology in the same generation has been confirmed only by humans and apes and is the first dolphin to be. The paper was published in the journal Current Biology on June 25.
The researchers focused on the hunting technique they call “shelling.” First, dolphins drive fish into a large shell that has fallen to the bottom of the sea. Next, lift this shell to the surface of the sea and catch the fish that flows down by shaking it with their nose.
In the case of dolphins, it’s usually the mother who teaches its infants how to hunt. For example, the mother dolphin in Shark Bay teaches the child how to use another tool called “sponging”. It is a method to protect it by attaching a sponge to the mouth when searching for food in the rock.
“The discovery that Schelling is not between mothers and children, but is transmitted within the peers is revolutionary. It highlights the similarity to primates in the sense of learning feeding behavior from both vertical and horizontal connections,” Michael Klewzen, an anthropologist at the University of Zurich, Switzerland, co-author of the paper, said in a press release.
Dolphins and apes have very different evolutionary histories and habitats. But they are mammals that live long and have big brains, and have the ability to create innovation and culture, he said.
Maggie Stanton, a psychologist at Franklin Marshall University who studies dolphins from Shark Bay and chimpanzees in Tanzania, also agrees. A chimpanzee family in Tanzania may have learned how to use tools to pull ants out from a female who joined the herd.
In 2007, Mr. Kleutzen began his research on dolphins in Shark Bay and identified more than 1,000 dolphins in 11 years. During this time, 19 dolphins were observed with 42 shellings. Half of that was seen in two years after the ocean heatwave in 2011. Marine heatwaves may have caused the mass death of shells, causing more shells to roll to the bottom of the ocean.
A long-term study also helped Schelling study that detailed information on the family history, age, gender, and behavior of individual dolphins was stored.
For example, shelling dolphins were acting with other Shelling dolphins. It’s likely that she imitated a fellow who spends time with her, said Sonya Wilde, a postdoctoral researcher at The University of Constance, Germany, the lead author of the paper. According to the paper, dolphins that do Schelling are always with their generation.
What factors are involved in this technology transmission? One is considered to be environmental factors. In other words, dolphins began to shelling simply because they lived in areas rich in shells. There is also the possibility that genetic factors are involved.
The researchers then created a computer model of various patterns that combine dolphin sightings with genetic and environmental data to transmit shelling between dolphins. As a result, the horizontal transmission model was the most powerful according to the paper.
Although 42 observations are few for datasets, researchers say Shelling is actually a common behavior. It’s only a few seconds of action, so it might just be hard to find it from the boat.
Like chimpanzees, dolphins live in a society that has led to a gradual. Among them, each individual moves freely between groups. That is, compared to, for example, a herd of baboons members of the group is fixed, it is to touch more in a variety of individuals and actions.
Mr Wild says it is similar to that of a human being. “Sometimes I’m with friends, sometimes I’m with my family. It’s going to change over the day.”
The new study is excellent in taking into account environmental and genetic factors related to shelling, he adds. “The results of this long-term field survey are irreplaceable data. You can’t get this data in any other way.”
Reference and Citations:
” Shelling out for dinner – Dolphins learn foraging skills from peers ” – University of Leeds