The Center for Whale Research said, external the death of any calf was a “tremendous loss” but added that the death of Tahlequah’s newborn was “particularly devastating” given its history.

The centre, which studies the Southern Resident killer whale and works on its conservation, said Tahlequah had now lost two out of four documented calves – both of which were female.

Both Canada and the US list Southern Resident killer whales as endangered.

The whales depend on Chinook salmon – which have been in dramatic decline in recent years – for food.

Failures to reproduce are linked to nutrition and access to these salmon, according to research from the University of Washington, external.

Whales can travel an average of 120km (75 miles) a day.

The 2018 sighting of Tahlequah pushing a dead calf happened when it was off the shores of Victoria, British Columbia.