Dolphin watchers discovered a rare occurrence recently off the New Zealand coast: A bottlenose dolphin adopted an abandoned common dolphin pup.
According to The New Zealand Herald, Kiwi made headlines five years ago when she lost her own baby, named Squirt, after getting stranded in a muddy inlet. Rescuers were able to return the mother to the ocean, but Squirt, which was nowhere to be found, was believed to have been eaten by an orca during the separation.
Since January Kiwi has been spotted swimming with a baby common dolphin, which has been given the name Pee-wee. Last week a group on a dolphin-watching trip in the Bay of Islands confirmed that some saw Kiwi nursing Pee-wee.
“It’s just so unusual,” marine mammal expert Jo Halliday told The New Zealand Herald. “The crew is ecstatic.”
Halliday believes that Kiwi hasn’t had another baby since Squirt, but the dolphin is producing milk.
“There’s so many things these guys are capable of doing. They may be able to switch on lactation on demand,” Halliday said.
Interspecies adoption among dolphins is not unheard of, but it’s rare. Scientists aren’t sure why, but Halliday thinks that the marine mammals are just inclined to help others during tough times. (Dolphin pups drink milk until about the age of six months, when they start fishing, a skill they likely learn by watching their mothers.)
According to Jenny Holland, author of the 2011 book Unlikely Friendships, interspecies adoptions are more common among domestic and captive animals, but they also occur in the wild. She told National Geographic that "mammals have the same brain structures, the same system, related to emotion that we have,” and that they “may take in another to relieve its pain, hunger, or loneliness.”
Kiwi's adoption of Pee-wee is yet more proof of the marine animals' intelligence and social nature, which have been well documented by scientists. Yet every year, Japanese fishermen in Taiji continue to slaughter hundreds of dolphins, sparing only some of the young ones to be sold to aquariums.
“Sometimes we don’t give them as much credit as they deserve for being complex, thinking, empathic beings,” said Holland.