According to Lori Mazzuca of Kallua Kona, Hawaii who won First Place for this photo in the Mammals category of the National Wildlife Awards:
“I was observing a strange interaction between a pair of bottlenose dolphins and a humpback whale, when it became apparent that the two species were collaborating in some way. The dolphin was lying on a humpback whale’s head while it was slowly swimming along. Looking through my camera lens the stunt appeared to be orchestrated by mutual “agreement.” The whale very slowly—and vertically—lifted the dolphin into the air. I expected the dolphin to wriggle atop the humpback’s head to get off, but it just laid still and arched, trying to stay on top of the whale’s snout. In this frame the dolphin was beginning its slippery return to the sea. Once back in the ocean, the dolphin swiftly swam away with the other dolphin, leaping joyfully as if they had just scored a coup!”
Mazzuca took this picture with a Canon EOS 10D; 70-200mm lens with 1.4x extender; digital capture.