Previous research found that dolphins have specific ‘names’ for themselves that consist of specific whistles. Researchers say that this ‘signature whistle’ basically tells other dolphins who he is.
Back in February, a research team at the University of St. Andrews found that dolphins actually call each other by those names. If loved ones become separated, they copy the lost dolphin’s signature whistle.
Just a few weeks ago, that team found even more evidence that dolphins really do call each other by name.
Researchers recorded a group of bottlenose dolphins and captured each individual’s signature whistle. They then played the calls back to the group as the “ultimate test” to see if the dolphins really react and respond to their own name. The researchers found that individuals responded only to their own call, definitively demonstrating that signature whistles function as names.
Now, the latest research shows that in addition to calling each other by name (a very human-like trait) dolphins also have incredibly good memories–probably the best in any non-human species.
After being apart for more than 20 years, dolphins can still recognize their old tank mates’ whistles. This is the longest social memory recorded in a non-human species.
Jason Bruck, who conducted the study and received his PhD from the University of Chicago’s program in Comparative Human Development says this shows that dolphins operate “cognitively at a level that’s very consistent with human social memory.”
Bruck collected data from 53 different captive bottlenose dolphins located at six facilities that have rotated dolphins and kept a record of which dolphins spent time together.
He played recordings of ‘signature whistles’ to dolphins that had previously lived with the ones who made those whistles. He then compared their reactions after hearing familiar calls to their reactions after hearing calls from dolphins they had never met. Bruck found that the dolphins responded immediately to the familiar calls.
“When they hear a dolphin they know, they often quickly approach the speaker playing the recording,” Bruck said in a news release. “At times they will hover around, whistle at it, try to get it to whistle back.”
The best example in the study was one dolphin named Bailey who recognized and responded to the recording of another dolphin that she hasn’t had contact with in 20 years and six months.
Bruck’s next project will be to see if those calls make one dolphin “picture another dolphin in its head.”
To learn more, check out some of these links:
- Dolphins keep lifelong social memories, longest in a non-human species
- Dolphins Call Each Other By Name
- The old grey whistle test
- Dolphins respond to individual names
Copyright © 2013 by Marine Science Today, a publication of Marine Science Today LLC.