Table 1.

Behavioral ethogram for human intruder

Category and specific behaviorsMeasurementBrief descriptions
FreezeDurationRigid, motionless posture except slight head movement
HostileCumulative frequency
    Threat barkFrequencyLow pitch, high intensity, rasping, guttural
    ThreatFrequencyAny of the following: open mouth (no teeth exposed), head bobbing, or ear flapping
    Cage aggressionFrequencyVigorously slaps, shakes, or slams body against cage
    LungeFrequencyA quick, jerky movement toward the stimulus
VocalizationsCumulative frequency
    CooFrequencyClear soft pitch and intensity, sounds like “ooooh”
    ScreamFrequencyHigh pitch, high-intensity screech or loud chirp
AnxietyCumulative frequency
    ScratchFrequencyRapid scratch of body with hands or feet
    Body shakeFrequencyShake of the whole body or just head and shoulders region
    Tooth grindaFrequencyRepetitive, audible rubbing of upper and lower teeth
    YawnFrequencyOpen mouth widely, exposing teeth
AffiliativebCumulative frequency
    LipsmackFrequencyRapid movement of pursed lips, accompanied by a smacking sound
    PresentFrequencyRigid posture (knees locked) with tail elevated and rump oriented toward the stimulus object
FearfulbCumulative frequency
    WithdrawalFrequencyQuick, jerky motion away from the stimulus object (jump back)
    GrimaceFrequencyRefracted lips, exposed clenched teeth
StereotypiesbCumulative duration
    PacingDurationRepetitive motor pattern around the test cage
    Motor stereotypyDurationRepetitive, abnormal voluntary or involuntary motor patterns (e.g., swinging, twirling, flipping)

  • List of all behaviors scored, how they are measured and a brief definition.

  • aBehavior for which total duration was also measured.

  • bBehavior that was rarely or never seen in the current study.