A species of Indonesian parrot can solve complex mechanical
problems that involve undoing a series of locks one after another, revealing
new depths to physical intelligence in birds.
A team of scientists from Oxford University, the University
of Vienna and the Max Planck Institute report in PLOS ONE a study in which ten
untrained Goffin's cockatoos faced a puzzle box showing food (a nut) behind a
transparent door secured by a series of five different interlocking devices,
each one jamming the next along in the series.