Off the coast of Portugal, a pod of sperm whales was seen adopting a lone bottlenose dolphin with a deformed, S-shaped spine that its own kind had apparently rejected, letting it swim, forage and nuzzle among them for weeks, the first time these deep-diving giants had ever been recorded forming a bond with another species, and no one can say what the whales got out of it.

What drove these massive deep-diving whales to nurture a disabled stranger when their own species abandoned it—and what did they gain in return? The post Off the coast of Portugal, a pod of sperm whales was seen adopting a lone bottlenose dolphin with a deformed, S-shaped spine that its own kind had apparently rejected, letting it swim, forage and nuzzle among them for weeks, the first time these…