Pink dolphins spotted with baby from completely different species in 'mystery' encounter

A rare, endangered baby dolphin has been spotted swimming with members of a different species in Cambodia, leaving scientists puzzled. 

The Irrawaddy dolphin (Orcaella brevirostris) calf was likely with its mother in a group of Indo-Pacific humpback dolphins (Sousa chinensis). Irrawaddy dolphins are dark gray with squished faces, while Indo-Pacific humpback dolphins are pink with long noses, so the calf and mother stuck out like saw thumbs. 

Researchers from Marine Conservation Cambodia (MCC) announced the sighting on May 31, posting on Facebook that the interaction was "extremely unusual" because the two species usually only come together when foraging in the same area. 

Becky Chambers, lead scientist at MCC's Cambodian Marine Mammal Conservation Project, told Live Science that her team was really excited to spot the calf, but they weren't sure why the two species were together.

"It is a bit of a mystery," Chambers said. "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."

Related: Dolphins are 'literally acting like jerks' by beating up baby manatees

Irrawaddy dolphins, known for spitting water out of their mouths and helping humans catch fish, are threatened with extinction partly because they get entangled in fishing gear. Researchers don't know how many Irrawaddy dolphins are left in the wild, but their population is severely fragmented, according to the IUCN Red List.