Researchers studying killer whales near Iceland spotted an unusual thing: An adult female orca was acting like a mother to a baby pilot whale. In fact, "unusual" is an understatement—it's the first such case on record, reports Insider. The young pilot whale was swimming right along side the adult orca, in the same way that an orca infant would, Marie Mrusczok, lead researcher of the study in the Canadian Journal of Zoology, tells Newsweek. How the unusual pairing came to be remains unclear. Both orcas and pilot whales have strong family relationships in the wild, though one researcher tells the CBC that the tale might not be as heartwarming as it sounds.
One possibility is that "she came across this orphan pilot whale calf that wasn't doing well, and that's the story we all think about, right?" says Elizabeth Zwamborn of Dalhousie University in Halifax. "This lovely warm adoption story. But there's also a decent chance that she actually abducted this calf from a group of pilot whales." The female orca, named Sædis, never had calves of her own, and it's possible that played a role. The pairing was spotted in 2021, and the calf was not seen with Sædis the following year. That raises the grim possibility the calf died because Sædis was unable to nurse it. About all researchers can be sure of that the relationships between killer whales and pilot whales "might be more complex than previously thought," per the study. (Read more orca stories.)