Dolphin calves left to fend for themselves stand little chance of surviving the perils of the wild - but fortunately, the ocean isn't always as unforgiving as it might seem. In an extremely rare show of empathy between marine mammals, wild bottlenose dolphin off the coast of New Zealand has been spotted playing ‘mom' to a helpless offspring that's of a type different from her own.
Marine experts say that the female dolphin, named Kiwi, is a regular visitor to the Bay of Islands, but she's recently been seen with an unlikely companion under her care - a baby common dolphin, dubbed Pee-wee. Bottlenose and common dolphins typically avoid one another at sea, which makes the apparent interspecies adoption all the more surprising.
"It's just so unusual," says local dolphin specialist Joanne Halliday, to the New Zealand Herald, describing reaction to the oddball family as "ecstatic."
While it's unclear how Pee-wee came to be orphaned, the calf looks to be well taken care of regardless. Kiwi appears to have taken on parenting duties full-time, and has even been observed nursing the calf with her own life-giving milk, suggesting a strong maternal bond has been formed.
Interestingly, the bottlenose dolphin's willingness to rear a common dolphin baby might stem from the tragic loss of her own calf. Five years ago, as a new mother, Kiwi made headlines after getting stranded on a sandbar in the Bay of Islands, becoming separated from her offspring. Although she was successfully rescued and refloated, Kiwi was never seen in the company of the calf again.
Interspecies adoptions aren't entirely unheard of among dolphins and other cetaceans. In 2011, biologists were surprised to discover a pod of sperm whales in the North Atlantic which had welcomed a dolphin with a deformity into their group, likely after he had become unable to keep up with his own kind.
The reasons behind such shows of solidarity between species is not fully understood, but researcher Jenny Holland suspects that, like humans, animals feel empathy too, and are inspired to "take in another to relieve its pain, hunger, or loneliness."
"Mammals have the same brain structures, the same system, related to emotion that we have," Holland writes in National Geographic. "So why not?"