The team observed six different types of grips: insertion (where the stick is entered into the cavity), lever (where the stick is used like a spoon to extract the food source from the cavity), prodding (where the stick pokes the inside of a cavity), screwing (where the stick is rotated with wrist movements in the cavity), stirring (where the stick is rotated in the cavity) and pounding (where the stick is used to hit the food source).
Birdily
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