The whale was spotted on Saturday, September 2, on the southwest side of the island.
The calf had a large gash on its back. However, it is believed to have died from natural causes and it is unlikely a boat’s propeller caused the injury.
Whale biologist Nan Hauser said it washed up on the reef among rocks, which may have contributed to its many cuts and abrasions.
Hauser was asked to fly out to Mauke to assess the whale and offer advice in how to dispose of its body.
However, because of prior commitments she was unable to leave Rarotonga, but instead talked to the head of the Environment Service on Mauke, Basilio Kaokao, by phone.
With the help of Air Rarotonga, Kaokao received a cooler kit with scalpers, containers and sterile instruments from Hauser and her team.
“We ran him through what samples we needed from the whale,” Hauser said. “The samples have been frozen.
“We will run all the lab and genetics tests and from there we will help Kaokao decide what to do with the animal.”
The 4.2-metre-long calf was reported to island officials who are yet to move the carcass.
“If they decide they want to get rid of it altogether, they will have to take it out some 4 miles so that sharks may feed off it,” Hauser said..
The whale expert said that by now the carcass would be emitting a strong odour, as it “cooks from the inside out”, saying that a decision would need to be made soon about the next step.
Hauser also said it had been quite some time since a dead whale had washed ashore in the Cook Islands, noting that normally the body would have been eaten by sharks before it reached the reef.
Hauser said residents had witnessed the calf’s mother returning to the carcass every day for the first half of the week.
“This is not unusual behaviour for whales, especially mother whales who have amazing bonds with their offspring.
“Humpback whales particularly, exhibit an immense amount of altruism.
“You know, we have had cases of humpback whales protecting and watching out for species that are not their own.
“There have been cases where they hide seals away from killer whales.
“It’s really beautiful.”
Hauser said her team unfortunately didn’t have sufficient funds in order to run an autopsy on the whale so they could understand exactly what happened with the whale, which was only a few weeks old.
Though upset at the loss of the young whale, Hauser said the prospect for incidents like this increased through winter.
Humpback whales arrive and breed within Cook Islands waters from around July to October each year.