Off the coast of Cambodia, a rare, endangered baby dolphin has been spotted swimming with a group of a different species.
Scientists from Marine Conservation Cambodia (MCC) stated that the interaction was strange because the two species only come together if they are foraging for food in the same area.
The calf was an Irrawaddy dolphin (Orcaella brevirostris). It was likely with its mother in a group of Indo-Pacific humpback dolphins (Sousa chinensis).
Irrawaddy dolphins have squished faces and dark-colored bodies, while Indo-Pacific humpback dolphins are pink with elongated noses. The sighting was announced on May 31 of 2024. It is unclear why they were together.
“It is a bit of a mystery,” said Becky Chambers, the lead scientist at MCC’s Cambodian Marine Mammal Conservation Project.
“These are both highly threatened populations of dolphins, and the fact that they’re having interactions is, at the moment, I would say neither good nor bad.”
Irrawaddy dolphins are known for spitting water out of their mouths and helping humans catch fish. They are at risk of extinction, and one of the contributing reasons is that they get tangled up in fishing gear.
The number of Irrawaddy dolphins left in the wild is unknown, but their population is small. Chambers and her team had been conducting dolphin surveys off southern Cambodia when they came across the Irrawaddy dolphin calf.
It is common to see juvenile dolphins, but this one was a newborn. Irrawaddy dolphins have mated with Indo-Pacific humpbacks to produce hybrid offspring before, but such occurrences are very rare.
Sign up for Chip Chick’s newsletter and get stories like this delivered to your inbox.
The young calf had all the features of an Irrawaddy dolphin, so it was most likely not a hybrid and was born from two Irrawaddy dolphin parents.
Both species are capable of alloparenting, which is when they provide care to young that are not their own direct offspring. In rare cases, it may even extend to other species altogether.
However, the researchers don’t know if the Indo-Pacific humpback dolphins were trying to care for the calf or cause harm to it.
Chambers pointed out that the Indo-Pacific dolphins could have been trying to separate the calf from its mother in an act of aggression.
But it seems that the calf was able to survive during the time it spent with the Indo-Pacific dolphins. A month later, the research team observed the calf again. This time, it was in a group of Irrawaddy dolphins.
“They didn’t have a good camera, so no photo ID could be taken on that occasion, but it would be likely that is the same individual, which is good if it is because it means the calf is still alive,” Chambers said.
They also noticed a single Indo-Pacific humpback dolphin swimming to the Irrawaddy group, which was another equally puzzling phenomenon.
