Researchers at the Far out Ocean Research Collective earlier this month were surprised to see a female bottled dolphin swim with a swimming pilot whale calf off the shores of New Zealand. Far from being lost, the young whale has been seen conversing with female bottlenecks like mother and baby, indicating that the little one has been adopted. Clearly, there are examples of unusual cross-species interactions. “Bottlenose dolphins are known as the adoption or‘acquisition ’of other species of calves,” the researcher wrote in an email to IFLScience with collective Jochen Zaeschmar.
“There are various records around the species boundary. However, adopted calves are usually species that are the same size or smaller than bottled dolphins as normal dolphins. Apparently, there has been at least one other incident of a pilot whale taking a calf in the Straits of Gibraltar, although it still surprised us.” While tissue-clutching-staffs may seem, Zaeschmar says the need to acquire such calves is not what they seem to be altruistic work. Bottled dolphins are known to steal calves, although this is probably the result of maternal instinctual misconduct without immediate thought before slander. In a Facebook post, Collective reported that the adoptive mother was spotted in a mixed group of liar killers and pilot whales; it could be where she chose the goat calf.
Fortunately, the mixing of this species in New Zealand waters is not uncommon so the calf may be adopted by its birth parents or others of the same species in the coming months. Zaeschmar explains that such eclipses usually don’t last more than a few months – and that a pilot whale will be much larger than a dolphin calf, eventually needing more milk than its bottled mother can deliver.
“The two are likely to reunite with the pilot whale again, and the calf may reunite with its own species even if it is not the mother of its birth,” Zaeschmar wrote. “Pilot whales communally leave their calves behind, which means even females can breastfeed without their own calves.”
