Sperm whales have the largest brains of any animal and live in complex matriarchal societies with cultural traditions passed between generations.
Sperm whale cognitive complexity and social bonds make welfare harms from social disruption particularly significant. The cultural transmission of coda dialects between generations means that disruption of social groups eliminates accumulated cultural knowledge alongside individual welfare harm. Ship strikes and entanglement cause traumatic injuries and death. Noise pollution from shipping and seismic surveys interferes with echolocation and communication. Their large brains and complex social lives create welfare needs that are genuinely comparable to those of great apes.