Bird Intelligence

Bird intelligence has been dramatically underestimated for most of scientific history — the pejorative 'bird-brained' reflected the assumption that small bird brains, lacking a neocortex (the mammalian seat of complex cognition), could not support sophisticated thought. Research since 2000 has overturned this: corvids (crows, ravens, jays, magpies) and parrots demonstrate cognitive abilities comparable to great apes, despite having brains the size of a walnut. Key findings: scrub jays hide food caches and re-hide them if watched by competitors (episodic memory, theory of mind); New Caledonian crows manufacture novel tools from unfamiliar materials (hooks from wire); rooks solve multi-stage cooperative problems (with 'collaborators' who can choose not to cooperate); Betty the crow made a hook spontaneously; Alex the African grey parrot understood numerical concepts including 'zero' (asked how many objects there were in an empty container, he said 'none' — demonstrating concept of absence); ravens plan for the future (choosing a tool now for a task they'll need tomorrow over an immediate food reward). The avian pallium (the forebrain region homologous to the mammalian cortex) has an extremely high neuron packing density — small brains can be efficient brains.