It's long been understood that dolphins and whales are incredibly intelligent, playful creatures. They regularly interact playfully with humans, and they've been seen doing the same with other species too.

However it's become apparent that all along the coast of Hawaii, bottlenose dolphins and humpback whales have formed a special kind of bond.

Lori Mazzuca. Marine Mammal Biologist at US Navy SPAWAR Systems Centre Pacific.

The initial image that sparked interest in the friendship was captured by Lori Mazzuca in Hawaii and posted on the Facebook page The Whale and Dolphin People Project. Mazzuca explained that she observed the dolphin and whale, shown above, seemingly playing with each other – the dolphin testing how long it could stay balanced on the humpback whale's head as it swam along. A powerful swimmer, the dolphin would eventually slide down the whale's back, tail-first before maneuvering its way back on top for another ride.

Photographer and marine biologist Mazzuca also coauthoured a paper studying the behaviors between the pair, suggesting "play by the whale and social play by the dolphin seem to be the most plausible explanations for the interaction."

More pictures of these two aquatic mammals having fun in the sun together began to surface all along the coasts of Hawaii's islands, showing that the event seen wasn't in isolatation.

When asked about the unusual behavior by Discovery, Ken Ramirez, vice president of animal care and training at Chicago’s Shedd Aquarium stated that “based on the description, I believe play would be the best explanation. If this were a video, there would be far more information to allow for better interpretation. But it is believed that the “surfing” or bow riding that dolphins exhibit in front of boats may have had its genesis in riding in front or in the wake of big whales.”

The American Natural History Museum has put together the following video, taking you on a guided tour around the islands and the images captured there.

It would appear that we are beginning to notice more and more interspecies relationships in the wild, with animals not just assisting each other for mutually beneficial reasons – like baboons and impala in Africa who help to alert each other to danger, but creatures simply enjoying each other’s company.

Who knows what other unusual partnerships occur away from the prying eyes of us humans?

[H/T Techly]