(CNN) - Two years ago, the world was stunned as an orca mother carried her dead newborn for more than two weeks. Now, that same killer whale is pregnant again.
Tahlequah, or J35, as researchers know it, is not the only southern orca resident to be pregnant.
According to the drone photos, she is just one of several pregnant killer whales that have been identified by investigators since early July, according to SR3, a marine life research, rehabilitation and response group.
In 2018, Tahlequah swam for 17 days with her dead newborn. Refusing to allow it to sink, she pushed her calf toward the surface of the Pacific off the coast of Canada and the Northwest United States.
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Aerial images of L72, another pregnant killer whale, in September 2019 and now in July 2020.
The killer whale population is a large extended family made up of three social groups, called herds, and killer whales from each herd are pregnant, according to SR3. However, it is unclear how many are waiting.
It is not unusual for females from all three herds to be pregnant at the same time, but the group said that most recent pregnancies have been unsuccessful.
"Studies by our colleagues at the University of Washington have shown that these reproductive failures are related to nutrition and access to their prey, Chinook salmon," the online statement said. "Therefore, we hope that our aquatic friends can give residents of the south plenty of space to feed at this important time."
The space to feed on these killer whales is crucial since the southern resident population is in a minimum of 73 of these animals, according to the Whale Research Center.
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SR3 shared online photos of J35 and L72, another pregnant killer whale. Aerial images of both killer whales show the size of their bodies in September, when they had spent several months in their pregnancies, and recently in July, with a greater width in the central part of the body, revealing that they are in their final stages.
Orcas are generally pregnant for 17-18 months, according to SR3.
- CNN's Darran Simon contributed to this report.
Orca whales
