World Bulletin / News Desk
A small population of dolphins in Western Australia state not only use sponges to help catch fish but the rare hunting technique has been passed from mother to daughter for generations, Australian researchers said.
Sightings of dolphins carrying sponges on their snouts to protect their sensitive noses while dislodging fish and crustaceans from the rocky ocean floor has been recorded since the 1980s.
But researchers at the University of New South Wales added a new dimension to their research by using computer modelling of behaviour and genetics to estimate how long the technique, which they call "sponging", has gone on.
"What's unique about the sponging behaviour is that only about five percent of dolphins use the sponges as a tool, and it's only one maternal line," said Anna Kopps at the University of New South Wales Evolution Ecologist Research Centre.
"What's new about this study now is we've got the time perspective," she told Reuters.
Scientists believe one single female started sponging in Shark Bay, Western Australia, and all her descendants in that area learned the behaviour from their mothers.
Knowing this, and that the sponging was done 30 years ago, computer modelling allowed them to study the spread of the behaviour over the past three decades -- and then reverse the process using genetics and behaviour to figure out when it might have begun.
Ultimately, they estimated that sponging has been going on for some 180 years, or roughly eight generations of dolphins.
"It's interesting that the behaviour doesn't spread to the entire population and it doesn't go extinct either," said Kopps.
Dolphin offspring are dependent on their mothers for about four years, giving them ample time to observe and learn survival techniques. The maximum lifespan of a dolphin is about 40 years.
"We don't know if it's teaching or other forms of learning," Kopps said.
While male dolphins also learn sponging from their mothers, the study found they don't pass the technique on.
"Some males use it but not many and it will be a dead end because they don't learn from the dads," Kopps said.
Last year 1.5 billion smartphones were sold around the world, according to research firm Gartner.
Russia's space agency said the unmanned Progress freighter carrying 2.5 tonnes of supplies including air, food and fuel "successfully docked" with the orbiting station at 0830 GMT.
Company givng $11.5M in grants to groups studying disparities in justice system
Firm joined forces with tech giants Ericsson, Intel, Qualcomm, and Samsung
NASA has made a major announcement in regard to search for life in the solar system
Demonstrations have been staged in Milan and Turin, where taxis blocked a main square for several days.
Dwarf planet in asteroid belt harbors ‘key ingredients for life’, researchers believe
Mark Zuckerberg writes an "essay" on Facebook, which offers a detailed, idealistic vision of the role of the world's biggest social network
Scientists who were at the launch in the southern spaceport of Sriharikota burst into applause as the head of India's Space Research Organisation (ISRO) announced all the satellites had been ejected.
The new apps -- for Apple TV, Amazon's Fire TV and Samsung Smart TV -- will provide a more convenient way for users of the social network to view videos on a large screen.
Ford said the investment would help it to realize a previously announced plan to introduce an autonomous vehicle for ride-hailing or ride-sharing service in 2021.
Assoc. Prof. Onay achieves to make DNA profiling in 34 minutes
Chan Zuckerberg Biohub promises 47 California scientists as much as $1.5 million each
In documents filed with the Securities and Exchange Commission, Snap said it took in $404 million in revenue last year but lost $515 million.
'There's a growing fear the U.S. is no longer a place that welcomes immigrants,' CEO Travis Kalanick says