The bond between the four generations is just another example of the strong mother-calf bonds in orca societies -- another aspect that marine parks have been criticized for disregarding. Recently, SeaWorld in particular touted the fact that it doesn't separate mothers and calves on Twitter, using a photo of a mother and calf pair that they had in fact separated. According to OrcaLab, pod continuity extends across several generations. Because orcas live so long and changes to pod composition are slow, development of new pods can take many generations.
Granny's adoption of Onyx is an example of how the orca family structure works when the mothers die or are taken from the pod. According to MacIntyre, being a surrogate mother isn't unusual for Granny.
"Granny did a lot of babysitting," she told The Dodo. "She's not even of reproductive age, but she's been helping care for other animals for years."
Thanks to these matriarchs' care, Onyx is happily swimming in his new J pod: