The female calf recently born to orca Tahlequah in Puget Sound, Washington, has died – and the grieving mother is once again reported to be keeping the body with her, as she famously did with a previous dead calf seven years ago.
Researchers from the Centre for Whale Research (CWR) had reported that the mother, officially designated J35 among the J pod of Pacific North-west killer whales, had given birth – but they had also warned that her behaviour and that of her calf J61 had given rise to health concerns, as Divernet reported on 27 December.
“The death of J61 is particularly devastating, not just because she was a female who could have one day potentially led her own matriline but also given the history of her mother J35, who has now lost two out of four documented calves – both of which were female,” stated the CWR.
It added that J35 had first been seen using her rostrum or a fin to carry J61’s body on New Year’s Day. Such mourning behaviour was known about, although her actions in 2018, when she covered a distance of 1,600km ln this way for 17 days, had drawn international attention because they were so extreme.
Killer whale pods are extended families that stay together for life. Grieving mothers can further express their emotions by altering their calls, reducing food intake or slowing their movements, while other orcas in the pod often stay close to provide support.
Shortage of salmon
J35’s first calf is now 14 and her third, born in 2020, is also alive. They form part of the critically endangered southern resident killer whale (SRKW) population, which is suffering from a shortfall in supplies of the Chinook salmon that provide their primary food source, combined with the effects of pollution, vessel noise and climate change.
The population has been reduced to 75, including what are believed to be only 23 breeding females.
NOAA Fisheries had previously reported that J35’s body condition had appeared ‘subnormal’, suggesting that she might not have been able to store enough fat for successful lactation, and that the calf was probably born prematurely and had not looked lively.
There were grounds for consolation for J35’s loss on the last day of 2024, however, with confirmation of the birth of another SRKW orca, designated J62. Seen among a number of adult females, its gender and the mother’s identity had yet to be established. “The calf appeared physically and behaviourally normal,” reported the CWS.
The researchers plan to conduct follow-up observations of both of J35 and new calf J62 as conditions and the orcas’ movements allow.
Also on Divernet: Bereaved killer whale surfaces with new calf, Did orca kidnap pilot whale calf?, Orca smashes record – but at what cost?, Diver’s orca binge brings record fine
