Interspecies Rivalry: Dolphins Defend Imperiled Humpback Whale Calf

A mother humpback whale found her young calf imperiled while swimming off Australia's southwest coast on Sunday.

In a mating attempt, five male whales surrounded Spirit, the mother, and Sunny, the calf in Flinders Bay near Augusta.

Help arrived from an unexpected source: a pod of bottlenose dolphins. Between 10 and 15 dolphins arrived to help Sunny and Spirit, who was attempting to disperse the males before her calf was injured.

The incident was reported by Whale Watch Western Australia, a tour agency whose passengers and staff saw the interaction.

After watching a video of the event, Director of the Marine Mammal Research Unit at The University of British Columbia Andrew Trites said the calf was "remarkably young" and perhaps only a month old.

A Humpback whale jumps in the surface of the Pacific Ocean at the Uramba Bahia Malaga National Natural Park in Colombia, on August 12. MIGUEL MEDINA/AFP/Getty Images

The drama began with the male group pursuing two mother-and-calf duos, according to a description of the event posted by the tour agency. After thirty minutes of pursuit, Sunny and Spirit separated from the other pair of humpbacks and swam toward the tour boat.

"For 40 minutes the Mother and calf kept very close to our vessel," a posting on the Whale Watch Western Australia website said. "The intensity and focus diminished from the males until one left the area and the lone male then behaved himself enough to be welcomed as an escort."

Trites described the reported interaction as "very puzzling" and said, "I haven't heard of that sort of thing happening before." The dolphins "responded as though it was an attack on one of their own. I'm not so sure it's altruistic, as in the dolphins know they're going to save another species," he told Newsweek. "They're acting instinctively without realizing the threat isn't a killer whale," Trites said, adding that curiosity could have also factored into the dolphins' response.

While remarkable, researchers have previously noted interactions between bottlenose dolphins and humpback whales. In 2004 and 2006, scientists documented two cases in which a humpback seemed to be playing with a bottlenose by lifting the dolphin out of the water.

This type of ostensibly playful interaction has also been documented with a number of other species, as well. A photo from September 2015 showed a seal surfing on a humpback whale, while a July 2015 video showed a genet in South Africa hitching a ride atop a black rhino.

Photographers have additionally captured images of some surprising collaboration among birds. Martin Le-May also captured a midflight picture showing a weasel riding a green woodpecker, and a photographer in California produced an image showing a crow riding on an eagle.