Table 1. Ethograms for behavioral assays.

Dominance Tube Test
Win	Subject animal remains in tube and the stimulus animal has fully exited the tube with all four paws on the ground.
Lose	Subject animal fully exits the tube with all four paws on the ground while the stimulus animal remains in the tube.
Tie	Neither animal fully exits tube within 3 minutes.
Novel Object Investigation
Latency to approach	Time at which subject’s nose is first within 1 cm of the object.
Time near object *	Subject is within one body length of the object but does not need to be oriented towards or actively investigating the object.
Time investigating object *	Subject’s nose is within 1 cm of the object.
Social Approach Test
Latency to approach	Time at which subject is first within one body length to the barrier.
Time near stimulus *	Subject is within one body length of the barrier but does not need to be oriented towards or actively investigating the subject.
Time investigating stimulus *	Subject’s nose is within 1 cm of the barrier.
Resident Intruder & Social Interaction Tests
Prosocial Behavior
Allogrooming	Subject grooms the stimulus animal.
Huddling	Subject and stimulus animals are either touching flanks or laying on top of each other.
Positive investigation	Subject sniffs or investigates stimulus animal without apparent aggression.
Positive side-by-side contact	Subject and stimulus animal are passively touching sides without apparent aggression.
Aggressive Behavior
Aggressive side-by-side contact	Subject and stimulus animals are touching flanks in an aggressive manner, sometimes between aggression bouts.
Biting	Subject bites the stimulus animal.
Chasing	Subject is aggressively chasing the stimulus animal and is the initiator for the entire event. Does not include non-aggressive following.
Lunging/Attacking/Rolling	Subject lunges at, swipes paws at, or rolls around with stimulus vole in aggression.
Pinning	Subject pins stimulus down.
Rearing	Subject is rearing up on hind paws in either offense or defense.
Nonsocial Behavior
Autogrooming	Subject grooms itself while not in contact with the stimulus animal.

* denotes that the behavioral state can co-occur with other states within an assay. Otherwise, all behavioral states are mutually exclusive.