Difficult Births in Killer Whales

Difficult Births in Killer Whales

J50, a southern resident killer whale that was featured much in the news lately, was instantly recognizable by the scars on her back, and many people attributed them to having a difficult birth. It was speculated that a family member may have acted as a “midwife” by physically pulling her out of the birth canal with their teeth. 

J50′s extensive scarring. Photo by Gary Sutton.

She is not, however, the only calf to have been documented with scars at birth. AB37, pictured at the top of this post, was a Southern Alaska resident killer whale born to AB6. AB37 was photographed shortly after birth with extremely severe scarring, even more prolific than J50′s. There was not much to be said about AB37 and her scars apart from the short description in the book “Killer Whales of Southern Alaska.” AB37 unfortunately was a likely victim of the Exxon Valdez oil spill as she disappeared soon after the spill at the young age of 3. Her entire family is now deceased, many of them also being lost to the oil spill. 

Might these scars be evidence of true killer whale “midwifery?” It’s virtually impossible to know. A killer whale birth has never been closely observed in the wild. The recent discovery of infanticide in transient killer whales has brought up the possibility that these scars are not necessarily from a family members aiding in a birth but actually something more far sinister. While infanticide hasn’t yet been observed in resident killer whales, it’s entirely possible the scars on these infants are in fact the result of marauding males attempting to kill them in order to force their mothers back into estrous so he could father calves instead of his rivals. Or perhaps these scars are from something else entirely that we still have yet to discover. 

One thing is certain: the first moments of life for these tiny whales were full of mystery and difficulty.