Free condition: Number of push and pull actions for ‘all actions’ and ‘successful actions’.

aAbsolute numbers of pushing and pulling for ‘all actions’ and ‘successful actions’.
bpercentages of ‘push’ in relation to the sum of pushing and pulling behaviours.
caverage percentage across individuals of a group.
dcalculation of significance of preference: binomial test p<0.05; expected proportion 0.5.
Action type with which the animal was first successful with is indicated in bracket: ps – push, pl – pull.
Animal names in bold indicate preference for the action the individual was first successful with.
Groups are indicated by the first letter of an individual's acronym. Group averages are shown below each group.