Orca kills calf so it can mate with its mother [Video]

• This is the first-ever recorded instance of an orca killing a newborn
• Scientists recorded this whole scene that lasted about 10 to 12 minutes
• The grieving mother fought back and bumped the killer hard enough to send plumes of blood into the air 
• Scientists were unable to confirm if the mother and the whale did end up mating after this incident

In a first, a male orca is seen killing and dragging a baby calf to the depths of the sea while its mother fights and wounds the killer whale.

Scientists off the coast of Vancouver recorded this behavior and the reason they say why a male orca would do this is most likely for sex. When a baby dies, it gives the female, or the mother of the dead calf, an opportunity to mate and reproduce again, speculate the scientists. The report was first published in the journal Nature.

The incident was documented in December 2016, but the study has only been published now. A report by The Washington Post (WP) pointed out that the orca calf that was murdered could not have been more than a few days old. It reportedly still had fetal folds on its body and its dorsal fins weren't fully erect as yet.

Just as the research team was wrapping up for the day, they reportedly heard a commotion in the water. "We got a little closer and realized that the baby whale we observed earlier wasn't surfacing," said Jared Towers, a cetacean researcher with Fisheries and Oceans Canada, who witnessed the event.

Just then, the 32-year-old male swam by with the baby lodged firmly in its teeth. "I knew right off the bat — I study killer whales pretty intensively — that this was a 'first of its kind' kind of observation," said Towers.

For the next five hours, the team collected data from inside the water as well as with photographs and video. "We were a bit horrified, but more so I think we were fascinated," Towers said. "We knew that it was time to just collect as much data as we could to accurately record our observations."

While rare, this kind of infanticidal behavior has been observed in mammals like primates and rodents. Some Dolphins have also been seen killing their infants. As to why an animal will kill a baby of its own species, Towers explains that it is, "a behavior that leads to sexual behavior".

This incident, however, is also notable because the male orca that killed the calf was aided by his mother. The baby's mother fought back, mentions the report. There was a lot violent bumping and biting, enough for the grieving mother to draw blood from the killer, but the mother of the killer whale intervenes.

This altercation ended about 10 to 12 minutes later. Till then, the dead baby was still being held by the male orca between his teeth, but the mother gave up, seeing her calf was already dead.

It is not known if the male orca was able to successfully mate with the female afterward as the researchers couldn't get enough samples.