Mr. Hanson said on Thursday that he did not know why the female calf, who lived for a few days during the last weeks of December, had died. The mother, one of only a few dozen of its type of orca, was seen carrying the dead female calf on Wednesday, though might have been doing so for longer.

The southern resident killer whale that carried its dead calf for more than two weeks in 2018 recently gave birth and has been spotted with the baby swimming healthily alongside it.