Dolphins have been observed playing with their food before they eat it. They rip off the heads and tentacles from cuttlefish before feeding it to their young.
The research published in the Australian Journal of Zoology says that dolphin mothers are trying to teach their calves how to kill their prey properly. They were spotted killing cuttlefish and squid in a number of stages – looking like they were playing with it. This is the first time this type of predatorial behaviour has been seen in dolphins in Western Australia.
The researchers from Murdoch University observed 15 dolphins carrying out this practice off the coast of Bunbury, Western Australia. Their study ran from 2007 to 2013. The mother would begin by catching a cuttlefish or squid, and bring it to the surface. They would then remove its head and tentacles, before squeezing the ink out of its neck from inside its body.
Then, in one sharp dive underwater, the dolphin would force the flesh away from the bone by using the pressure of the water. The bones would float to the surface, and the young calf would enjoy its meal of flesh.
"Dolphins often develop complex ways to find food that is unique to their habitat," Kate Sprogis, co-author of the report, told news.com.au. "However, consuming cuttlefish in [this] manner has only been reported in two other places around the world."
Cuttlefish are near-threatened in Australia, and their falling population numbers may have a knock-on effect to dolphins, the researchers say.
"Our study contributes valuable information to the limited knowledge of the complex prey-handling by [bottlenose dolphins]," the study authors wrote.
They will continue to observe bottlenose dolphins around Australia, as well as develop their knowledge of cuttlefish species. They will study their abundance, distribution and egg-laying to further understand the importance of cuttlefish in dolphin's diet.