The researchers from the Australian National University (ANU), who are working with local guides, said in an ANU statement that the blue whale’s reproductive and calving behaviour was “largely unknown in the scientific community until now.

The footage was recorded off the coast of Dili as part of the annual monitoring of the Australi-Indonesian population of pygmy blue whales.

“From newborn calves and nursing mothers to amorous adults in courtship, the waters of Timor-Leste really are providing blue whale scientists with some of our first glimpses into the private lives of one of the world’s largest but most elusive animals,” said Professor Karen Edyvane, Program leader and marine ecologist, who has been conducting research from Dili since 2006.

The scientific milestone was achieved by researchers swimming with snorkels alongside the birthing and nursing whales.

In the statement, a clear video of a blue whale and calf feeding was shared.

Marine scientists sounded positively relieved about their discoveries in Timor-Leste.

“It’s very exciting,” said Professor Edyvane. “Our decade-long project has documented some of the lesser-known intimate reproductive behaviours of blue whales, some for the very first time.”

International marine scientists, including Edyvane, have identified the waters around Timor-Leste’s as a global cetacean hotspot and potential major migration corridor for whales and dolphins.