VICTORIA -- A second new baby orca has been born to a pod of endangered southern resident killer whales off Victoria.

The Pacific Whale Watch Association and the Washington-based Center for Whale Research say J-pod orca J41, also known as Eclipse, gave birth Thursday in waters southwest of B.C.'s capital city.

It's the second calf born to J-pod in September after a male calf was born to Tahlequah, or J35, approximately three weeks ago.

Tahlequah gained international attention for carrying her dead calf more than 1,600 kilometres across the ocean for 17 days back in 2018.

The newest calf is Eclipse's second after the birth of J51 in 2015.

Researchers say the birth was witnessed by naturalists Talia Goodyear and Leah Vanderwiel, as well as those aboard a whale watching vessel from Orca Spirit Adventures.

The vessel was returning from viewing dozens of humpbacks in the region when it came upon the lone pregnant orca southwest of Race Rocks, according to the association.

"After going under for several minutes, she reappeared, and this time it looked like she was pushing something with her rostrum [nose]," Goodyear said in a statement.

The naturalist described an "emotional rollercoaster" as observers initially thought the pregnant orca might be entangled.

"At which point the little one started surfacing on its own," Vanderwiel said. "It appeared to be a rambunctious little bundle of baby, as every surface was exaggerated and playful."

The naturalists say the mother and calf then headed southwest.

Baby orca

"It took a few minutes to realize what was actually happening, but then it was pure excitement realizing that it was a birth and the baby was very alive and boisterous," said Vanderwiel.

The Center for Whale Research says 40 per cent of newborn calves do not survive their first few weeks.

"It's too soon to determine the status of the calf, and further observations are necessary before we'll make an announcement of the new baby's health," said the centre's founder and executive director, Ken Balcomb.

Researchers have yet to identify the sex of the newborn. There are an estimated 74 southern resident orcas in the wild.