Nature

Grieving ordeal of mother orca, who carried her dead calf for 17 days and 1,600km, is finally over

J35 is back to frolicking with her pod, looking ‘vigorous and healthy’

PUBLISHED : Monday, 13 August, 2018, 10:45am
UPDATED : Monday, 13 August, 2018, 10:45am

A grieving mother orca has finally dropped her dead calf after carrying the body for 17 days, drawing worldwide concern.

“J35 frolicked past my window today with other J pod whales, and she looks vigorous and healthy,” Ken Balcomb, founding director of the Centre for Whale Research in Friday Harbour, Washington, wrote in an email. “The ordeal of her carrying a dead calf for at least seventeen days and 1,000 miles (1,600km) is now over, thank goodness.”

J35 is part of the critically endangered southern-resident killer-whale population. Balcomb said J35 probably has lost two other offspring since giving birth to a male calf in 2010.

J35 showed no signs of “peanut head,” a condition that betrays malnutrition in an orca, as cranium bones begin to show. “She’s been eating,” Balcomb said.

People around the world were moved by the plight of the southern residents as J35 carried her dead baby, a female, day after day.

Another member of the population, a 4 1/2-year-old known as J50, also is ailing. Biologists were working over the weekend to monitor her condition.

The Lummi Nation was standing by to feed J50 live salmon.

A veterinary review of J50 Thursday night encouraged veterinarians and biologists who said her condition is better than they expected. But she remains terribly thin and severely malnourished.

Lack of food also has been linked to the southern residents’ failure for three years now to produce offspring.

“The reason J35 lost her baby and the others are losing their babies is there is not enough salmon,” Balcomb said of the whales’ primary food source. “Hopefully we will do something about that.”

It is possible that rather J35’s the baby simply finally fell apart. When the calf was sighted last Thursday, it was beginning to decompose.

J35 had emphatically clung to the calf, diving deeply to retrieve it each time it slid from her head.

Biologists tracking her worried she might not be getting anything to eat, and might also be slipping into danger.

At 20, J35 is an extraordinarily valuable member of the critically-endangered southern-resident clan, potentially with years of reproductive potential ahead of her if she can get enough to eat.

Scientific research has shown that at least three problems are causing the decline of the southern-resident clan, in the J, K, and L pods of orca whales.

Vessel noise interrupts their foraging behaviour. Toxins are released from their blubber when they burn their fat because they are hungry. And malnutrition in a top predator that needs to swim 120km a day is a devastating blow. Hunger also makes their other problems worse.

J35’s behaviour was not unusual. Orcas, dolphins and other mammals, including gorillas, are known to carry their deceased young in what is widely believed by scientists to be an expression of grief.

But J35’s action was extraordinary in its duration – unprecedented among documented examples.

Sheila Thornton, lead killer-whale biologist for Fisheries and Oceans Canada, said strong social bonds between the families of orcas drive much of their behaviour. The southern residents share food, a language, a culture of eating only fish and an ecological knowledge of where to find it in their home range.

Today, with only 75 members left in the southern-resident clan, the question is what now will be done to save them from extinction.