Herman Melville’s Moby Dick may paint a picture of the sperm whale as a terrifying, ferocious creature that destroys ships and attacks the sailors on them, but modern research shows thatsperm whales are compassionate and social creatures, dangerous only to the fish and squid that the giant whale feasts on for dinner, or to the orca whales that prey on sperm whale calves. A heartwarming and unusual recent discovery does even more to distinguish the sperm whale from its deadly reputation, as a group of sperm whales were observed “adopting” a bottlenose dolphin with a spinal malformation.

Behavioral ecologists Alexander Wilson and Jens Krause discovered this unique phenomenon when they set out to observe sperm whales off the island of Pico in the Azores in 2011. Upon arriving there, they discovered a whale group of adult sperm whales, several whale calves, and an adult male bottlenose dolphin. Over the next eight days, the pair observed the dolphin with the whales six more times, socializing and even nuzzling and rubbing members of the group. At times, the sperm whales seemed merely to tolerate the dolphin’s affection, while at others, they reciprocated. “It really looked like they had accepted the dolphin for whatever reason,” Wilsonreports to ScienceNOW. “They were being very sociable.”

This gregarious dolphin was easily recognizable by its spinal malformation, a rare spinal curvature that gave the dolphin’s back half an “S” shape. This malformation did not seem to affect the dolphin’s overall health, but  was likely the reason that the dolphin joined up with the sperm whales in the first place. In the highly social and clique-based world of dolphins, such a disfigurement could have given the dolphin low social status, or may have prevented the dolphin from fitting in and keeping up with its peers.