Springer, an orphaned killer whale rescued by humans and reintroduced to her pod, has given birth in the wild, marking the only known occasion where an orca put back into the wild after human intervention has given birth.

Graeme Ellis, a research technician with Fisheries and Oceans Canada's Pacific Biological Station, told National Geographic that finding Springer with a baby is "the ultimate sign that this whole reintroduction was a success. It was very exciting."

"Her calf was healthy and active and energetic," Ellis said, adding that the calf was about seven feet long.

Paul Spong, director of the research station OrcaLab, said that learning a released orca had successfully given birth in the wild was a confirmation of everything the orca research community believed about the possibility of the whale resuming a normal life.

In 2002, Springer was found orphaned in the waters of Puget Sound about 300 miles from her pod. Local media named the whale "Little Orca Annie." Orca researchers worried about the mental health of the whale. Usually social animals, the orphaned whale had resorted to interacting with pieces of driftwood instead of other whales, according to National Geographic.

After Springer, now 13, was first released back into the wild, her caregivers became concerned after the whale chose not rejoin her nearby pod, but went straight to to a piece of driftwood instead.

However the whale slowly became reintegrated with her pod and began travelling with them.

Orca experts say that because Springer is swimming among and mating with other whales in the pod, it's a sign of successful reintegration.

"The social system these whales live in is so closed that if we could not get her back to her own pod, it is unlikely she would have been accepted," said John Ford biologist with Cetacean Research Program at Fisheries and Oceans Canada, according to the Seattle Times. 

"It gives us hope that if such an event happens in the future, provided that all the right bits are in place-that is, knowing who the animal is and what group it comes from-that these kinds of efforts can be successful," he said.