Table 2. Ethogram for all behavioural observations.

Activity	Description
Stereotypic behaviour1
Locomotor stereotypy	Movement or sequence of whole body movements repeated at least three times consecutively (‘scrabbling’ excluded; see below)
Borderline stereotypy	Apparent locomotor stereotypy interrupted before three repetitions or switching between elements of common stereotypies without repeating a sequence three times
Scrabbling	Repetitive scratching at wall of cage or nest-box
Wire-gnawing	Standing or lying with the mouth closed around the wire front of the cage
Inactivity	Lying still
Social play2*	Rough and tumble play (biting, sparring with paws, chasing, jumping onto cagemate), differentiated from aggression by the absence of hissing, screaming and/or persistent attempts to escape
General activity	Animal neither inactive nor engaged in stereotypic behaviour; includes eating, drinking and grooming, and enrichment use
E use	Mink is interacting with an enrichment while active; includes sniffing, carrying, moving or chewing it (thus excludes e.g. sleeping with an enrichment in the nest-box)
Object play2	A subset of E use excluding sniffing and similar exploratory behaviour: biting, pushing (with paws or nose), lifting, jumping on, manipulating (with paws), or chasing object

¹Assessment required interruption of scan with a focal observation of up to 10 s (cf. e.g. [10]).

²Assessed in juvenile mink only, Experiment 2.